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Publisher: Elsevier   (Total: 3031 journals)

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Showing 1 - 200 of 3031 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 79, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 22, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 303, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 196, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 21, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 4)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 119, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 38, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 41, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 33, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 7, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 6, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 20, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 14)
Advances in Pharmacology     Full-text available via subscription   (Followers: 13, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 17, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 56)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 1, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 332, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Surgery     Full-text available via subscription   (Followers: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 28, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 14)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 42, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 303, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 388, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 29, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 36, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 48, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 3, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 7, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 45, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 45, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 47, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 25, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 48, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 173, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 51, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 22, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 32, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 13, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 52, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 3)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 151, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 7, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 141, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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Journal Cover Agricultural Systems
  [SJR: 1.275]   [H-I: 74]   [29 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0308-521X
   Published by Elsevier Homepage  [3031 journals]
  • Performance of process-based models for simulation of grain N in crop
           rotations across Europe
    • Authors: Xiaogang Yin; Kurt Christian Kersebaum; Chris Kollas; Sanmohan Baby; Nicolas Beaudoin; Kiril Manevski; Taru Palosuo; Claas Nendel; Lianhai Wu; Munir Hoffmann; Holger Hoffmann; Behzad Sharif; Cecilia M. Armas-Herrera; Marco Bindi; Monia Charfeddine; Tobias Conradt; Julie Constantin; Frank Ewert; Roberto Ferrise; Thomas Gaiser; Iñaki Garcia de Cortazar-Atauri; Luisa Giglio; Petr Hlavinka; Marcos Lana; Marie Launay; Gaëtan Louarn; Remy Manderscheid; Bruno Mary; Wilfried Mirschel; Marco Moriondo; Isik Öztürk; Andreas Pacholski; Dominique Ripoche-Wachter; Reimund P. Rötter; Françoise Ruget; Mirek Trnka; Domenico Ventrella; Hans-Joachim Weigel; Jørgen E. Olesen
      Pages: 152 - 165
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Xiaogang Yin, Kurt Christian Kersebaum, Chris Kollas, Kiril Manevski, Sanmohan Baby, Nicolas Beaudoin, Isik Öztürk, Thomas Gaiser, Lianhai Wu, Munir Hoffmann, Monia Charfeddine, Tobias Conradt, Julie Constantin, Frank Ewert, Iñaki Garcia de Cortazar-Atauri, Luisa Giglio, Petr Hlavinka, Holger Hoffmann, Marie Launay, Gaëtan Louarn, Remy Manderscheid, Bruno Mary, Wilfried Mirschel, Claas Nendel, Andreas Pacholski, Taru Palosuo, Dominique Ripoche-Wachter, Reimund P. Rötter, Françoise Ruget, Behzad Sharif, Mirek Trnka, Domenico Ventrella, Hans-Joachim Weigel, Jørgen E. Olesen
      The accurate estimation of crop grain nitrogen (N; N in grain yield) is crucial for optimizing agricultural N management, especially in crop rotations. In the present study, 12 process-based models were applied to simulate the grain N of i) seven crops in rotations, ii) across various pedo-climatic and agro-management conditions in Europe, iii) under both continuous simulation and single year simulation, and for iv) two calibration levels, namely minimal and detailed calibration. Generally, the results showed that the accuracy of the simulations in predicting grain N increased under detailed calibration. The models performed better in predicting the grain N of winter wheat (Triticum aestivum L.), winter barley (Hordeum vulgare L.) and spring barley (Hordeum vulgare L.) compared to spring oat (Avena sativa L.), winter rye (Secale cereale L.), pea (Pisum sativum L.) and winter oilseed rape (Brassica napus L.). These differences are linked to the intensity of parameterization with better parameterized crops showing lower prediction errors. The model performance was influenced by N fertilization and irrigation treatments, and a majority of the predictions were more accurate under low N and rainfed treatments. Moreover, the multi-model mean provided better predictions of grain N compared to any individual model. In regard to the Individual models, DAISY, FASSET, HERMES, MONICA and STICS are suitable for predicting grain N of the main crops in typical European crop rotations, which all performed well in both continuous simulation and single year simulation. Our results show that both the model initialization and the cover crop effects in crop rotations should be considered in order to achieve good performance of continuous simulation. Furthermore, the choice of either continuous simulation or single year simulation should be guided by the simulation objectives (e.g. grain yield, grain N content or N dynamics), the crop sequence (inclusion of legumes) and treatments (rate and type of N fertilizer) included in crop rotations and the model formalism.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.eja.2016.12.009
      Issue No: Vol. 84 (2017)
       
  • Freshwater use in livestock production—To be used for food crops or
           livestock feed?
    • Authors: Ylva Ran; Corina E. van Middelaar; Mats Lannerstad; Mario Herrero; Imke J.M. de Boer
      Pages: 1 - 8
      Abstract: Publication date: July 2017
      Source:Agricultural Systems, Volume 155
      Author(s): Ylva Ran, Corina E. van Middelaar, Mats Lannerstad, Mario Herrero, Imke J.M. de Boer
      Current approaches to estimate freshwater use in livestock production systems generally fail to consider the competition for water resources with alternative uses, such as production of food crops food or other ecosystem services. This article presents a new method to account for the competition for freshwater use between food crops and animal feed, while assessing freshwater use in livestock production systems. The developed water use ratio (WUR) is defined as the maximum amount of human digestible protein (HDP) derived from food crops from the consumptive water use (CWU) appropriated to produce 1kg of animal-source food (ASF) over the amount of HDP in that 1kg of ASF. The CWU for livestock production is first categorized according to the land over which it is consumed, based on the suitability of that land to produce food crops. Then, the method assesses food-feed competition by determining the amount of HDP that could have been produced from food crops, using the same CWU currently used to produce ASF. The method enables identification of livestock production systems that contribute to global food supply without competing significantly over water resources with food production, based on their CWU. Three beef production systems in Uruguay are used to illustrate the method. During the backgrounding and the finishing stages, which are analyzed in this study, cattle can be kept on natural pasture (NP), seeded pasture (SP) or in feedlots (FL). The following three systems were analysed: i) NP-NP, ii) SP-SP and iii) SP-FL. Results show that the NP-NP system uses the largest amount of water per kg of beef output. However, results also show that the SP-SP and SP-FL systems can potentially produce more HDP by growing food crops than by producing beef. Based on the traditional measure for water productivity, i.e. the quantity of CWU per kilo of beef produced, we would conclude that the NP-NP system is least efficient, whereas based on the WUR the NP-NP system is the only system producing HDP more efficiently than food crops. Sustainable intensification not only implies improving agriculture and livestock productivity per unit of resource used, but also improving the number of human beings nourished. Results from this study illustrate the importance of considering competition and trade-offs with other uses when evaluating water use efficiency of livestock systems to promote sustainable intensification.

      PubDate: 2017-04-11T18:44:05Z
      DOI: 10.1016/j.agsy.2017.03.008
      Issue No: Vol. 155 (2017)
       
  • Gauging the sources of uncertainty in soybean yield simulations using the
           MONICA model
    • Authors: Rafael Battisti; Phillip S. Parker; Paulo C. Sentelhas; Claas Nendel
      Pages: 9 - 18
      Abstract: Publication date: July 2017
      Source:Agricultural Systems, Volume 155
      Author(s): Rafael Battisti, Phillip S. Parker, Paulo C. Sentelhas, Claas Nendel
      Crop models are an important tool to evaluate crop management strategies and simulate yield for present and future scenarios, however, much uncertainty is present within model parameters, approaches and input variables. Therefore, it is important to quantify the uncertainties in simulated yields as a function of input details from field management decisions and their effect on simulated regional soybean yield. To investigate this, the Model for Nitrogen and Carbon in Agroecosystems (MONICA), calibrated with experimental data, was used in this study. Four sources of uncertainty relevant to field management were considered in simulating soybean yields: technological level, soil type, sowing date and cultivar maturity group. The uncertainties in yield simulation were investigated for 14 sites in Southern Brazil, comparing results to governmental statistics for the crop seasons from 1989/1990 to 2013/2014. The MONICA model was able to simulated soybean grain yield efficiently after calibration of crop phases, growth and root-development parameters. The technological level (TL) was the yield factor with the highest coefficient of variation (CV) among the fourteen sites, with an average of 31.4%, while cultivar maturity group and sowing date both had a CV of 10%, and soil 4.4%. However, uncertainties varied with climate conditions in each crop season, with sowing date and cultivar maturity group both showing higher CV than technological level in some crop seasons. In some cases, for regional yield level, the model demonstrated varied performance by location. The most accurate performance was in simulating yields in the municipality of Passo Fundo (r=0.87), while in Bagé, the lowest accuracy was achieved (r=0.07), across all factors. However, in Bagé, when the lower yields simulated by MONICA, for all source of uncertainties were considered, simulated yields were close to those observed for most of the crop seasons. Based on these results, it is important to consider these different sources of uncertainty that stem from farmer decision-making in order to simulate regional soybean yield efficiently.

      PubDate: 2017-04-19T19:04:48Z
      DOI: 10.1016/j.agsy.2017.04.004
      Issue No: Vol. 155 (2017)
       
  • Farm types and farmer motivations to adapt: Implications for design of
           sustainable agricultural interventions in the rubber plantations of South
           West China
    • Authors: James Hammond; Mark T. van Wijk; Alex Smajgl; John Ward; Tim Pagella; Jianchu Xu; Yufang Su; Zhuangfang Yi; Rhett D. Harrison
      Pages: 1 - 12
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): James Hammond, Mark T. van Wijk, Alex Smajgl, John Ward, Tim Pagella, Jianchu Xu, Yufang Su, Zhuangfang Yi, Rhett D. Harrison
      Tropical land use is one of the leading causes of global environmental change. Sustainable agricultural development aims to reduce the negative environmental impacts of tropical land use whilst enhancing the well-being of the smallholder farmers residing in those areas. Interventions with this goal are typically designed by scientists educated in the Western tradition, and often achieve lower than desired uptake by smallholder farmers. We build on work done in farm type classification and studies of factors that influence adaptation, trialling a suite of household survey questions to elucidate the motivational factors that influence a farmer's willingness to adapt to external change. Based on a sample of 1015 households in the rubber growing region of Xishuangbanna, South-west China, we found that farm types based on structural characteristics (e.g. crops, livelihoods) could not be used to accurately predict farmers' motivations to adapt. Amongst all six farm types identified, the full range of motivational typologies was found. We found six motivational types, from most to least likely to adapt, named: Aspirational Innovators, Conscientious, Copy Cats, Incentive-centric, Well Settled, and Change Resistant. These groups roughly corresponded with those identified in literature regarding diffusion of innovations, but such classifications are rarely used in development literature. We predict that only one third of the population would be potentially willing to trial a new intervention, and recommend that those sectors of the population should be identified and preferentially targeted by development programs. Such an approach requires validation that these motivational typologies accurately predict real behaviour – perhaps through a panel survey approach. Dedicated data gathering is required, beyond what is usually carried out for ex-ante farm typologies, but with some refinements of the methodology presented here the process need not be onerous. An improved suite of questions to appraise farmers' motivations might include value orientations, life satisfaction, and responses to various scenarios, all phrased to be locally appropriate, with a scoring system that uses the full range of potential scores and a minimum of follow up and peripheral questions.

      PubDate: 2017-03-04T05:50:03Z
      DOI: 10.1016/j.agsy.2017.02.009
      Issue No: Vol. 154 (2017)
       
  • Prioritizing investments for climate-smart agriculture: Lessons learned
           from Mali
    • Authors: N. Andrieu; B. Sogoba; R. Zougmore; F. Howland; O. Samake; O. Bonilla-Findji; M. Lizarazo; A. Nowak; C. Dembele; C. Corner-Dolloff
      Pages: 13 - 24
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): N. Andrieu, B. Sogoba, R. Zougmore, F. Howland, O. Samake, O. Bonilla-Findji, M. Lizarazo, A. Nowak, C. Dembele, C. Corner-Dolloff
      Agricultural productivity and growth in Mali are under threat from erratic rainfall, resulting in more frequent dry years. The national economy is vulnerable to climate change due to 50% of the gross domestic product coming from the agricultural sector and 75% of the population living in rural areas. The Climate-Smart Agriculture (CSA) concept arises from a need to provide innovative solutions towards the complex and integrated goals of increasing yields, improving resilience, and promoting a low emissions agricultural sector. A major challenge for policymakers to operationalize CSA is the identification, valuation (cost-benefit), and subsequent prioritization of climate-smart options and portfolios (groups of CSA options) for investment. This paper presents the process, results, and lessons learned from a yearlong pilot of the Climate-Smart Agriculture Prioritization Framework (CSA-PF) in Mali. Key national and international stakeholders participated in the co-development and prioritization of two CSA portfolios and related action plans for the Malian Sudanese zone. Initial steps towards outcomes of the process include inclusion of prioritized CSA practices in ongoing development projects and prompting discussion of modifications of future calls for agricultural development proposals by regional donors.

      PubDate: 2017-03-09T13:17:04Z
      DOI: 10.1016/j.agsy.2017.02.008
      Issue No: Vol. 154 (2017)
       
  • Diversity of high-latitude agricultural landscapes and crop rotations:
           Increased, decreased or back and forth?
    • Authors: Pirjo Peltonen-Sainio; Lauri Jauhiainen; Jaana Sorvali
      Pages: 25 - 33
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Pirjo Peltonen-Sainio, Lauri Jauhiainen, Jaana Sorvali
      Land use change is a continuously on-going process that has many impacts on the environmental footprint of agriculture and especially on the biodiversity of agricultural landscapes. This study used field scale data from 1995 to 2011 (165,760 field parcels) on a study region that represents the prime crop production area of Finland, to assess how agricultural land use has changed since the launching of the EU Common Agricultural Policy. Six five-year crop rotation types were identified: cereal species monoculture, cereal monoculture, rotation with a break-crop, diverse crop rotation, perennial, non-permanent grassland rotation and environmental fallow rotation. Shifts in the frequencies of different crop rotation types and composition of their crop species were monitored. Furthermore, the contribution of different field characteristics, on a farmer's land allocation to different rotation types, was assessed. The ultimate goal was to understand whether land use changes, in general, have contributed to any increase in heterogeneity of landscapes and whether they have impacted diversity of crop rotation types. We found that different crop rotation types were applied on a farm, but that farmers have quite consistent drivers for land allocation to different rotation types; although, economic incentives influence the introduction, expansion and/or withdrawal of crops from rotations. The farmers' readiness to implement land use changes was dependent on farm size. There has been a shift towards lower shares of cereal species monocultures, grassland rotations and diverse crop rotations, while environmental fallow rotations have increased. According to the five-year rotation plans shared by 16 interviewed farmers, there was a noted desire for more diverse rotation types originating from adverse experiences with cereal monocultures and soil degradation; however, they were keen on reducing the number of environmental fallows and concentrating on food production. It is important to carry out follow-up studies to understand the impacts of the demonstrated and anticipated land use changes on biodiversity. Future policy development should benefit from a gained understanding of the drivers of farmers' decisions for facilitating unimpeded implementation.

      PubDate: 2017-03-09T13:17:04Z
      DOI: 10.1016/j.agsy.2017.02.011
      Issue No: Vol. 154 (2017)
       
  • On-farm compliance costs and N surplus reduction of mixed dairy farms
           under grassland-based feeding systems
    • Authors: Gabriele Mack; Robert Huber
      Pages: 34 - 44
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Gabriele Mack, Robert Huber
      Grassland-based feeding systems have the potential to reduce N input in agriculture through lower use of concentrates. Switzerland has recently introduced a new voluntary grassland-based milk and meat programme that restricts the concentrate and maize use in milk production systems. We analysed the on-farm compliance costs and the N surplus reduction potential for a sample of 2004 mixed dairy farms using farm-optimisation models implemented in the agent-based agricultural sector model SWISSland. Based on the simulation results, we used regression analysis to identify driving forces for the level of compliance costs and the reduction in N surplus of farms which allowed to investigate the effectiveness and the efficiency of the programme for the whole farm population. Our results imply that a payment for reducing the on-farm consumption of concentrate and maize feed does not substantially reduce N surpluses in Swiss agriculture. The heterogeneity of farms results in a distribution of compliance costs with a large group of farms having no or minimal costs. With the current payment of 200 CHF per hectare, reductions of 10.7 and 26.3tonnes of N can be achieved at high costs of 57 and 161 CHF per kg N in the lowland and mountain region respectively. Results also imply that specialisation represented by a high proportion of milk production, high levels of milk yields per cow as well as high milk prices increases the on-farm compliance costs of the programme. In contrast, diversification strategies that focus on intensive milk production in combination with additional low N fed livestock to optimise the use of grass at farm level reduces the compliance costs.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.003
      Issue No: Vol. 154 (2017)
       
  • Forecasting sugarcane yields using agro-climatic indicators and Canegro
           model: A case study in the main production region in Brazil
    • Authors: Valentina Pagani; Tommaso Stella; Tommaso Guarneri; Giacomo Finotto; Maurits van den Berg; Fabio Ricardo Marin; Marco Acutis; Roberto Confalonieri
      Pages: 45 - 52
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Valentina Pagani, Tommaso Stella, Tommaso Guarneri, Giacomo Finotto, Maurits van den Berg, Fabio Ricardo Marin, Marco Acutis, Roberto Confalonieri
      Timely crop yield forecasts at regional and national level are crucial to manage trade and industry planning and to mitigate price speculations. Sugarcane is responsible for 70% of global sugar supplies, thus making yield forecasts essential to regulate the global commodity market. In this study, a sugarcane forecasting system was developed and successfully applied to São Paulo State, the largest cane producer in Brazil. The system is based on multiple linear regressions relating agro-climatic indicators and outputs of the sugarcane model Canegro to historical yield records. The resulting equations are then used to forecast the yield of the current season using 10-day period updated values of indicators and model outputs as the season progresses. We quantified the reliability of the forecasting system in different stages of the sugarcane cycle by performing cross-validations using the 2000–2013 time series of official stalk yields. Agro-climatic indicators alone explained from 38% of inter-annual yield variability (at State level) during the boom growth phase (i.e., January–April) to 73% during the second half of the harvesting period (i.e., September–October). When Canegro outputs were added to the regressor set, the variability explained increased to 63% for the boom growth phase and 90% after mid harvesting, with the best performances achieved while approaching the end of the harvesting window (i.e. at the beginning of October, SDEP=0.8tha−1, R2 cv =0.93). It is concluded that the overall performances of the system are satisfactory, considering that it was the first attempt based on information exclusively retrieved from the literature. Further improvements to operationalize the system could be possibly achieved by the use of more accurate inputs possibly supplied by the collaboration with local authorities.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.002
      Issue No: Vol. 154 (2017)
       
  • Ecosystem-based interventions and farm household welfare in degraded
           areas: Comparative evidence from Ethiopia
    • Authors: Kindie Getnet; Wolde Mekuria; Simon Langan; Mike Rivington; Paula Novo; Helaina Black
      Pages: 53 - 62
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Kindie Getnet, Wolde Mekuria, Simon Langan, Mike Rivington, Paula Novo, Helaina Black
      Agricultural productivity and farm household welfare in areas of severe land degradation can be improved through ecosystem-based interventions. Decisions on the possible types of practices and investments can be informed using evidence of potential benefits. Using farm household data together with a farm level stochastic simulation model provides an initial quantification of farm income and nutrition outcomes that can be generated over a five year period from manure and compost based organic amendment of crop lands. Simulated results show positive income and nutrition impacts. Mean farm income increases by 13% over the planning period, from US$32,833 under the business as usual situation (application of 50kg DAP and 25kgureaha−1 yr−1) to US$37,172 under application of 10tha−1 yr−1 farm yard manure during the first three years and 5tha−1 yr−1 during the last two years. As a result of organic soil amendment, there is an associated increase in the available calorie, protein, fat, calcium, and iron per adult equivalent, giving the improvement in farm household nutrition. The evidence is substantive enough to suggest the promotion and adoption at scale, in degraded ecosystems, of low cost organic soil amendment practices to improve agricultural productivity and subsequent changes in farm household welfare.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.001
      Issue No: Vol. 154 (2017)
       
  • Potential benefits of diverse pasture swards for sheep and beef farming
    • Authors: Iris Vogeler; Ronaldo Vibart; Rogerio Cichota
      Pages: 78 - 89
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Iris Vogeler, Ronaldo Vibart, Rogerio Cichota
      To investigate the potential use of diverse pasture swards to reduce nitrate leaching from intensive sheep and beef farms while maintaining economic viability, an integrated modelling assessment was conducted for the Canterbury region, New Zealand. The biophysical Agriculture Production Systems Simulator (APSIM) was used to obtain pasture growth curves for simple and diverse pastures over 10 different years, and the whole-farm system models FARMAX® and OVERSEER® were used to examine feed flow, nutrient balance, profitability, and nitrate leaching. The N leaching estimates obtained from OVERSEER® nutrient budget model (Overseer) were compared to estimates from APSIM. Five farm scenarios were explored, including three different proportions of the flat farm area under simple and diverse pastures (100% simple, 100% diverse, 50/50), two different stocking policies (without and with adjustment of livestock numbers), and three different years (an average, a best and a worst year, based on annual pasture yields). In the average year pasture growth was similar for the simple and diverse pasture swards, with annual pasture yields of 8.98 and 9.23tDM/ha. The simple pasture had slightly higher growth in winter due to lower sensitivity to cold temperatures, whereas the diverse pasture showed higher growth during summer, which is frequently prone to water limitations. However, in the best year modelled pasture growth as well as profit were higher for the simple compared with the diverse pasture sward. Pasture N concentrations ranged from 2.5 to 3.5% of dry matter (DM) in the simple pasture, and from 2.2 to 3.1% in the diverse pasture sward, mainly due to a lower proportion of legumes. For the average year, having a diverse pasture on 50% of the farm area without changing the stocking policy of the farm, increased farm profit by 16%, due to the sale of surplus pasture. The total farm N leaching values predicted by APSIM, based on excretal N amounts obtained from Overseer, showed that the use of diverse pastures on 100% of the flat area decreased N leaching in an average year by 35%. In the worst year however, N leaching under the diverse pasture was slightly higher, and in the best year it decreased by 14% compared with the simple pasture. Corresponding reductions in N leaching estimated from Overseer were 6, 5 and 13% for the diverse pasture, primarily due to the lower N concentration of the diverse pasture. In contrast to APSIM, Overseer does not take into account the higher uptake of N of diverse pastures from the urine patches compared to simple pastures, which is mainly due to increased pasture growth in summer of the species included in the diverse pasture. This potential of diverse pastures to decrease N leaching needs to be evaluated via experimental studies, which should also include other aspects such as pasture persistence, and address the need for accurate model parameterisation. The modelling work also provided guidance for model refinement.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.015
      Issue No: Vol. 154 (2017)
       
  • Disentangling agronomic and economic yield gaps: An integrated framework
           and application
    • Authors: Michiel van Dijk; Tom Morley; Roel Jongeneel; Martin van Ittersum; Pytrik Reidsma; Ruerd Ruben
      Pages: 90 - 99
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Michiel van Dijk, Tom Morley, Roel Jongeneel, Martin van Ittersum, Pytrik Reidsma, Ruerd Ruben
      Despite its frequent use in policy discussions on future agricultural production, both the concept of the yield gap and its determinants are understood differently by economists and agronomists. This study provides a micro-level framework that disentangles and integrates agronomic and economic approaches to yield gap measurement. It decomposes the conventional yield gap indicator into four components that together provide a better understanding of why actual farm yield falls below potential: (1) the technical efficiency yield gap, (2) the allocative yield gap, (3) the economic yield gap and (4) the technology yield gap. The results can be used to inform targeted policy and farming recommendations at plot, farm household, local and national level. The framework is operationalised and tested by combining results from crop models with detailed farm and plot level survey data for maize production in Tanzania.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.004
      Issue No: Vol. 154 (2017)
       
  • CCAFS-MOT - A tool for farmers, extension services and policy-advisors to
           identify mitigation options for agriculture
    • Authors: Diana Feliciano; Dali Rani Nayak; Sylvia Helga Vetter; Jon Hillier
      Pages: 100 - 111
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Diana Feliciano, Dali Rani Nayak, Sylvia Helga Vetter, Jon Hillier
      CCAFS-MOT is a tool to support farmers, policy advisors and agricultural extension services on the choice of management practices that reduce greenhouse gas emissions (GHG) without risking food security. It is an Excel-based tool which brings together several empirical models to estimate GHG emissions in rice, cropland and livestock systems, and provides information about the most effective mitigation options. Greenhouse gas emissions are estimated in terms of carbon dioxide equivalent per hectare (kgCO2eqha−1) and carbon dioxide equivalent per unit of product (kgCO2eqkg−1). Baseline management practices are chosen by the user and a set of mitigation options are ranked according to their mitigation potential. The tool allows different levels of input to be specified from an introductory to detailed level, depending on objectives and issues like to accommodate users with different backgrounds and details concerning input data. As such it allows for product and region specific assessments of GHGs and mitigation potentials to be made without the need for expert knowledge or for lengthy model set-up and calibration.
      Graphical abstract image

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.006
      Issue No: Vol. 154 (2017)
       
  • Incorporating grain legumes in cereal-based cropping systems to improve
           profitability in southern New South Wales, Australia
    • Authors: Hongtao Xing; De Li Liu; Guangdi Li; Bin Wang; Muhuddin Rajin Anwar; Jason Crean; Rebecca Lines-Kelly; Qiang Yu
      Pages: 112 - 123
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Hongtao Xing, De Li Liu, Guangdi Li, Bin Wang, Muhuddin Rajin Anwar, Jason Crean, Rebecca Lines-Kelly, Qiang Yu
      Grain legumes, such as lupins and field peas, are one of key rotation components in Australian agricultural systems, supplying nitrogen (N) to following crops, and potentially increasing farm profitability. In this study, we used a modelling approach to investigate the profitability of incorporating field pea (Pisum sativum) and narrowleaf lupin (Lupinus angustifolius) in cereal-based (wheat/canola) cropping systems in southern New South Wales (NSW), Australia. We calibrated and validated the Agricultural Production Systems sIMulator (APSIM) with three-year's experimental data to predict yields of field pea and lupin, and N contribution of grain legumes in cereal-based (wheat/canola) crop rotations. We conducted a gross margin analysis to analyse the profitability of adding grain legumes into cereal-based crop rotations at both crop and rotation levels. The simulated results showed that field pea and lupin could contribute 30–65kgNha−1 to the next crop and 60–110kgNha−1 to subsequent crops (wheat/canola) for two years, corresponding to 30–55% and 60–86% of net N inputs of legume-fixed N, respectively. This greatly increased the yields and profitability of wheat/canola in the following two years. Including grain legumes in cereal-based crop rotations was more profitable than non-legume crop rotations, even though the grain legumes were less profitable than wheat/canola in the year of growing. However, N and economic benefits would be reduced to zero if N fertilizer applied to wheat/canola was over the optimal level, i.e. 100–125kgNha−1 in terms of N benefit, or 75kgNha−1 for farm-economic profit. In general, incorporation of grain legumes into cereal-based crop rotations offers an obvious N benefit to subsequent crops and provides an economic benefit for farmers (reduced N applications). This suggests that the contribution of grain legumes to cereal-based cropping systems should be assessed as part of a rotation rather than as a stand-alone crop.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.010
      Issue No: Vol. 154 (2017)
       
  • An economic and greenhouse gas emissions evaluation of pasture-based dairy
           calf-to-beef production systems
    • Authors: Brian Murphy; Paul Crosson; Alan K. Kelly; Robert Prendiville
      Pages: 124 - 132
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Brian Murphy, Paul Crosson, Alan K. Kelly, Robert Prendiville
      The objectives of the current study were to investigate the effects of production system on Holstein-Frisian bulls and steers and also to evaluate the profitability and greenhouse gas (GHG) emissions of these production systems. Calves were assigned to one of five production systems; bulls finished indoors on a concentrate ad libitum diet for 200days and slaughtered at 15months of age (15MO); bulls finished indoors on a concentrate ad libitum diet for 100days and slaughtered at 19months of age (19AL); bulls supplemented with 5kg of concentrate dry matter (DM) per head daily at pasture for 100days and slaughtered at 19months of age (19PC); steers supplemented with 5kg DM of concentrate per head daily at pasture for 68days and slaughtered at 21months of age (21MO) and steers finished indoors on grass silage plus 5kg DM of concentrate per head daily for 92days and slaughtered at 24months of age (24MO). All calves were rotationally grazed at pasture, supplemented with 1kg DM of concentrates per head daily, during the first season. With the exception of 15MO all production systems were fed grass silage and 1.5kg DM of concentrate during the winter period and returned to pasture for a second season. The Grange Dairy Beef Systems Model was used to simulate whole-farm system effects of production systems while GHG emissions associated with production were simulated using the Beef Systems Greenhouse Gas Emissions Model. Carcass weight was lowest for 21MO, greatest for 19AL and 24MO with both 15MO and 19PC intermediate. Conformation score was greater for bull (15MO, 19AL and 19PC) compared to steer production systems (21MO and 24MO). Fat score was greatest for 24MO and lowest for both 15MO and 19PC; 19AL and 21MO were intermediate. Concentrate feed costs represented 68, 59, 47, 39 and 39% of the total variable costs for 15MO, 19AL, 19PC, 21MO and 24MO, respectively. The most profitable production system was 19PC, while the least profitable systems were 15MO and 24MO. Greenhouse gas emissions, on a per kg live weight and carcass weight basis were lowest for 15MO and 19AL and greatest for 21MO and 24MO. The current study showed that slaughtering bulls at 19months of age and finishing at pasture was the most profitable production system with moderate GHG emissions.

      PubDate: 2017-03-28T13:42:08Z
      DOI: 10.1016/j.agsy.2017.03.007
      Issue No: Vol. 154 (2017)
       
  • Homegardens and the future of food and nutrition security in southwest
           Uganda
    • Authors: Cory W. Whitney; John R.S. Tabuti; Oliver Hensel; Ching-Hua Yeh; Jens Gebauer; Eike Luedeling
      Pages: 133 - 144
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Cory W. Whitney, John R.S. Tabuti, Oliver Hensel, Ching-Hua Yeh, Jens Gebauer, Eike Luedeling
      Governments around the world seek to create programs that will support sustainable agriculture and achieve food security, yet they are faced with uncertainty, system complexity and data scarcity when making such choices. We propose decision modeling as an innovative approach to help meet these challenges and offer a case study to show the effectiveness of the tool. We use decision analysis tools to model the possible nutrition-related outcomes of the Ugandan government's long term agricultural development plan termed ‘Vision 2040’. The analysis indicates potential shifts in household nutritional contributions through the comparison of the current small-scale diverse systems and the envisioned industrial agricultural systems that may replace them. A Monte Carlo simulation revealed that Vision 2040 plans outperform homegardens in terms of energy and some macronutrients, yet homegardens are likely to be better at producing key vitamins and micronutrients, such as Vitamin A. Value of information calculations applied to Monte Carlo outputs further revealed that gathering more data on the annual yields and nutrient contents of staples, pulses, vegetables, and fruits could improve certainty about the nutrition contribution of both scenarios. We conclude that the development of Uganda's agricultural sector should consider the role that agrobiodiversity in the current small-scale agricultural systems plays in national food and nutrition security. Any changes according to Vision 2040 should also include farmers' voices and current crop management systems as guides for a sustainable food supply in the region. This modeling approach may be a tool for governments to consider agricultural policy implications, especially given the data scarcity and agricultural variability in regions such as East Africa.

      PubDate: 2017-04-11T18:44:05Z
      DOI: 10.1016/j.agsy.2017.03.009
      Issue No: Vol. 154 (2017)
       
  • Environmental impact trade-offs in diet formulation for broiler production
           systems in the UK and USA
    • Authors: C.W. Tallentire; S.G. Mackenzie; I. Kyriazakis
      Pages: 145 - 156
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): C.W. Tallentire, S.G. Mackenzie, I. Kyriazakis
      The environmental impacts associated with broiler production arise mainly from the production and consumption of feed. The aim was to develop a tool for formulating broiler diets designed to target and reduce individually specific environmental impact categories in two contrasting regions, the UK and USA. Using linear programming, least cost broiler diets were formulated for each region, using the most common genotype specific to each region. The environmental impact of the systems was defined using 6 categories calculated through a Life Cycle Assessment (LCA) method: global warming potential (GWP), fresh water eutrophication potential (FWEP), marine eutrophication potential (MEP), terrestrial acidification potential (TAP), non-renewable energy use (NREU) and agricultural land use (ALU). Diets were then formulated for each region to minimise each impact category, without compromising bird performance. The diets formulated for environmental impact objectives increased their cost in most cases by between 20 and 30% (the cost increase limit), with the exception of the least GWP (+16%) and the least NREU (+4%) diets in the UK, and the least TAP diet in the USA (+14%). The degree of flexibility to reduce simultaneously several environmental impact categories in the UK and the USA differed due to the different feed ingredients available to each region. The results suggested there was potential to minimise several impact categories simultaneously by reducing the impact of one impact category compared to least cost, through diet formulation in the UK; this was shown to a greater and lesser extent in the least FWEP and the least NREU diet formulations respectively. In the USA, there was no way to minimise one impact category through diet formulation without increasing other impact categories caused by the system. Employing a multi-criteria approach to diet formulation methodologies, where environmental impact as well as economic implications are considered, will form an important pillar in broader efforts to improve the sustainability of animal production.

      PubDate: 2017-04-11T18:44:05Z
      DOI: 10.1016/j.agsy.2017.03.018
      Issue No: Vol. 154 (2017)
       
  • Resource basis, ecosystem and growth of grain family farm in China: Based
           on rough set theory and hierarchical linear model
    • Authors: Yang Gao; Xiao Zhang; Lei Wu; Shijiu Yin; Jiao Lu
      Pages: 157 - 167
      Abstract: Publication date: June 2017
      Source:Agricultural Systems, Volume 154
      Author(s): Yang Gao, Xiao Zhang, Lei Wu, Shijiu Yin, Jiao Lu
      Based on resource-based theory and enterprise ecosystem theory, this paper used the sample of Huang-huai-hai plain 487 grain family farms, in the basis of attribute reduction by rough set theory, introduce the important individual-level and provincial-level factors into hierarchical linear model, in order to reveal different level factors affect growth of grain family farm in structural differences and interaction. The results showed that 65.68% of the differences were caused by individual-level factors, and 34.32% were caused by provincial-level factors. The factors at the individual level, including the improvement of production equipment (IPE), education of farmers (EOF), regularization of management rules (RMR), and difficulty level of getting loans (DLL), had positive effects on growth of family farm, whereas the frequency of staff participating in training (FST) had a negative effect. At provincial level, improvement of the support policy system (IDSPS) could strengthen the positive correlation between RMR and growth of family farm. Moreover, the factor IDSPS combined with ability of agricultural cooperatives providing social services (AACPS) and spacious degree of technology access channel (SDTAC) could strengthen the positive correlation between EOF and growth of family farm, and reduced the negative correlation between FST and dependent variable. The results suggested that government should support farms to improve production equipment and financing pattern, transfer the method of re-education of grain family farmers, promote the standardization of grain family farms, establish a sound policy support system, improve the social service ability of agricultural cooperatives, and broaden the channels of technology acquisition.

      PubDate: 2017-04-11T18:44:05Z
      DOI: 10.1016/j.agsy.2017.03.013
      Issue No: Vol. 154 (2017)
       
  • Could EU dairy quota removal favour some dairy production systems over
           others? The case of French dairy production systems
    • Authors: Thibault Salou; Hayo M.G. van der Werf; Fabrice Levert; Agneta Forslund; Jonathan Hercule; Chantal Le Mouël
      Pages: 1 - 10
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Thibault Salou, Hayo M.G. van der Werf, Fabrice Levert, Agneta Forslund, Jonathan Hercule, Chantal Le Mouël
      Since the 1st of April 2015, European dairy quotas, one of the iconic instruments of the Common Agricultural Policy, have been removed. With this removal, the European Commission expects to develop a more competitive and market-oriented dairy sector in light of increasing world food demand. In countries such as France, where quotas were administratively managed and strongly linked to land, this system maintained dairy production in all regions but also sustained inefficient dairy production systems. With quota removal, changes such as concentration of production in the most favourable areas, enlargement of dairy farms and restructuring of the dairy sector to increase the efficiency of production systems are likely. The impacts of quota removal on markets, as well as the localisation of dairy production, have been widely studied. The impacts on the distribution of dairy production across various production systems have been less studied. We use MATSIM-LUCA, a partial equilibrium economic model, to assess the impacts of dairy quota removal on i) markets and prices and ii) redistribution of production among dairy production systems in France. We consider several world demand scenarios for dairy and meat products to test the sensitivity of our results to future world demand for these products. Our results confirm the findings of previous studies, i.e., quota removal causes an increase in milk production and a decrease in raw milk prices in the European Union. Market effects are similar regardless of the world demand scenario, but they are markedly higher in the high world demand scenario. Our results regarding the impacts of quota removal on the shares of different dairy production systems in France are new and original. We find that quota removal alone has limited impacts on the redistribution of production across dairy systems. Quota removal associated with increased world demand has stronger impacts, but the expected redistribution effects towards more efficient systems remain rather limited even then. Our results show that the very intensive maize system is the most responsive to changes in the production context.

      PubDate: 2017-01-29T18:44:30Z
      DOI: 10.1016/j.agsy.2017.01.004
      Issue No: Vol. 153 (2017)
       
  • Stepwise frameworks for understanding the utilisation of conservation
           agriculture in Africa
    • Authors: Brendan Brown; Ian Nuberg; Rick Llewellyn
      Pages: 11 - 22
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Brendan Brown, Ian Nuberg, Rick Llewellyn
      Despite the large and ongoing investment in the promotion of Conservation Agriculture (CA) to African smallholder farmers, currently available estimates of adoption provide little insight into the realities of their use. Both the technologies and their adoption tend to be poorly defined, leading to large variation in estimates and validity issues. To address this void, we propose two independent but complementary frameworks: the Conservation Agriculture Appraisal Framework (CAAF) is used to quantify the intensity of implementation of CA; and the Process of Agricultural Utilisation Framework (PAUF) is used to classify various types of use and non-use by disaggregating the adoption process into ten stages. These frameworks are applied to household survey data across five eastern and southern African countries from 1,601 village and 6,559 households. Overall, we find a general overestimation of adoption of CA and CA components. By considering in more detail the intensity of implementation and the types of use and non-use, new meaning is found in the status and contributors to limited CA utilisation.
      Graphical abstract image

      PubDate: 2017-01-29T18:44:30Z
      DOI: 10.1016/j.agsy.2017.01.012
      Issue No: Vol. 153 (2017)
       
  • Influence of post-weaning management system during the finishing phase on
           grasslands or feedlot on aiming to improvement of the beef cattle
           production
    • Authors: Rondineli P. Barbero; Euclides B. Malheiros; Renata L.G. Nave; John T. Mulliniks; Lutti M. Delevatti; Jefferson F.W. Koscheck; Elieder P. Romanzini; Adriana C. Ferrari; Diego M. Renesto; Telma T. Berchielli; Ana C. Ruggieri; Ricardo A. Reis
      Pages: 23 - 31
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Rondineli P. Barbero, Euclides B. Malheiros, Renata L.G. Nave, John T. Mulliniks, Lutti M. Delevatti, Jefferson F.W. Koscheck, Elieder P. Romanzini, Adriana C. Ferrari, Diego M. Renesto, Telma T. Berchielli, Ana C. Ruggieri, Ricardo A. Reis
      The effects of differing post-weaning management systems applied during the wet season were evaluated on the performance of 108 young Nelore (Bos taurus indicus) bulls finished on grasslands or feedlot system during the dry season. In Exp. 1, three grazing heights (15cm, 25cm, and 35cm) of Brachiaria brizantha (Hochst ex A. Rich) Stapf Marandu were evaluated during the wet season with bulls receiving 0.3% of body weight (BW) in supplementary feed. In Exp. 2, supplementation levels were decreased as grazing heights were increased such as: (1) low height (15cm) and high supplementation (0.6% BW) (LH–HS); (2) moderate height (25cm) and moderate supplementation (0.3% BW) (MH–MS); or (3) high height (35cm) with no supplementation (HH–NS). In both experiments, at the end of the wet season, a half of the bulls were finished on grasslands and receiving 1.0kg/100kg BW of dietary supplementation while the remaining bulls were placed in a feedlot system. A non-linear regression test was applied (linear plateau) to estimate the point of stabilization of DMI on feedlot. The experimental design was completely randomized in a factorial arrangement 3 (post-weaning system)×2 (finishing systems), consisting of three replicates (lots of three bulls) per treatment (n =18, each Exp.). In the Exp. 1, the post-weaning system using 35cm of grazing height had greater BW (P =0.04) through the finishing phase in comparison with bulls grazing 15cm of grazing height. However, the ADG during the initial 21days of the finishing phase was changed by grazing height used during the post-weaning phase (P =0.004), and by finishing system (P =0.007). The post-weaning system did not alter the carcass weight (P =0.63), but the bulls finished on grasslands exhibited greater carcass weight (P =0.02) than bulls finished on feedlot. In the Exp. 2, non-supplemented bulls (HH-NS) took a longer time (±10%) to DMI stabilization on feedlot (P <0.01). There were no changes in the carcass weight caused by post-weaning system (P =0.84), or by finishing system (P =0.14). The evaluated systems combining increasing grazing height and decreasing supplementation level during the post-weaning phase can be used during the wet season according to the economic background or production target, once these systems do not influence the finishing phase.

      PubDate: 2017-01-29T18:44:30Z
      DOI: 10.1016/j.agsy.2017.01.015
      Issue No: Vol. 153 (2017)
       
  • To mulch or to munch? Big modelling of big data
    • Authors: D Rodriguez; P de Voil; MC Rufino; M Odendo; MT van Wijk
      Pages: 32 - 42
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): D Rodriguez, P de Voil, MC Rufino, M Odendo, MT van Wijk
      African farmers are poorly resourced, highly diverse and aground by poverty traps making them rather impervious to change. As a consequence R4D efforts usually result in benefits but also trade-offs that constraint adoption and change. A typical case is the use of crop residues as mulches or as feedstock. Here we linked a database of household surveys with a dynamic whole farm simulation model, to quantify the diversity of trade-offs from the alternative use of crop residues. Simulating all the households in the survey (n=613) over 99 years of synthetic climate data, showed that benefits and trade-offs from “mulching or munching” differ across agro-ecologies, and within agro-ecologies across typologies of households. Even though trade-offs between household production or income and environmental outcomes could be managed; the magnitude of the simulated benefits from the sustainable intensification of maize-livestock systems were small. Our modelling framework shows the benefits from the integration of socio-economic and biophysical approaches to support the design of development programs. Our results support the argument that a greater focus is required on the development and diversification of farmers' livelihoods within the framework of an improved understanding of the interconnectedness between biophysical, socio-economic and market factors.

      PubDate: 2017-01-29T18:44:30Z
      DOI: 10.1016/j.agsy.2017.01.010
      Issue No: Vol. 153 (2017)
       
  • Capturing systemic interrelationships by an impact analysis to help reduce
           production diseases in dairy farms
    • Authors: Margret Krieger; Susanne Hoischen-Taubner; Ulf Emanuelson; Isabel Blanco-Penedo; Manon de Joybert; Julie E. Duval; Karin Sjöström; Philip J. Jones; Albert Sundrum
      Pages: 43 - 52
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Margret Krieger, Susanne Hoischen-Taubner, Ulf Emanuelson, Isabel Blanco-Penedo, Manon de Joybert, Julie E. Duval, Karin Sjöström, Philip J. Jones, Albert Sundrum
      Production diseases, such as metabolic and reproductive disorders, mastitis, and lameness, emerge from complex interactions between numerous factors (or variables) but can be controlled by the right management decisions. Since animal husbandry systems in practice are very diverse, it is difficult to identify the most influential components in the individual farm context. However, it is necessary to do this to control disease, since farmers are severely limited in their access to resources, and need to invest in management measures most likely to have an effect. In this study, systemic impact analyses were conducted on 192 organic dairy farms in France, Germany, Spain, and Sweden in the context of reducing the prevalence of production diseases. The impact analyses were designed to evaluate the interrelationships between farm variables and determine the systemic roles of these variables. In particular, the aim was to identify the most influential variables on each farm. The impact analysis consisted of a stepwise process: (i) in a participatory process 13 relevant system variables affecting the emergence of production diseases on organic dairy farms were defined; (ii) the interrelationships between these variables were evaluated by means of an impact matrix on the farm-level, involving the perspectives of the farmer, an advisor and the farm veterinarian; and (iii) the results were then used to identify general system behaviour and to classify variables by their level of influence on other system variables and their susceptibility to influence. Variables were either active (high influence, low susceptibility), reactive (low influence, high susceptibility), critical (both high), or buffering (both low). An overall active tendency was found for feeding regime, housing conditions, herd health monitoring, and knowledge and skills, while milk performance and financial resources tended to be reactive. Production diseases and labour capacity had a tendency for being critical while reproduction management, dry cow management, calf and heifer management, hygiene and treatment tended to have a buffering capacity. While generalised tendencies for variables emerged, the specific role of variables could vary widely between farms. The strength of this participatory impact assessment approach is its ability, through filling in the matrix and discussion of the output between farmer, advisor and veterinarian, to explicitly identify deviations from general expectations, thereby supporting a farm-specific selection of health management strategies and measures.

      PubDate: 2017-02-05T19:12:51Z
      DOI: 10.1016/j.agsy.2017.01.022
      Issue No: Vol. 153 (2017)
       
  • Modelling farm-level adaptation of temperate, pasture-based dairy farms to
           climate change
    • Authors: Electra Kalaugher; Pierre Beukes; Janet F. Bornman; Anthony Clark; David I. Campbell
      Pages: 53 - 68
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Electra Kalaugher, Pierre Beukes, Janet F. Bornman, Anthony Clark, David I. Campbell
      Projections indicate that climate change may exacerbate existing challenges to the productivity of New Zealand dairy farming systems. To assess the importance of these projections and understand adaptation challenges at farm level, detailed farm-scale model simulations of climate change impacts were undertaken for six representative pasture-based dairy farms located in the major dairying regions of New Zealand. The analysis suggested that without adaptation, climate change is likely to have a negative impact in most of the study locations. However, the level and type of impact depends to a large degree on regional climate variability as well as on the management practices of each farm. Under current management, responses to projected climate changes ranged from no change to an 18% decrease in average annual pasture production. A number of modelled adaptations demonstrated the potential to reduce climate change impacts under current management. The modelling work, together with farmers' responses, showed the adaptations' potential to provide both benefits and management challenges across different regions and climate conditions. In particular, it highlighted the need for the results of farm systems modelling under climate change scenarios to be considered in the context of their specific and localised climatic and management challenges.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.008
      Issue No: Vol. 153 (2017)
       
  • Big Data in Smart Farming – A review
    • Authors: Sjaak Wolfert; Lan Ge; Cor Verdouw; Marc-Jeroen Bogaardt
      Pages: 69 - 80
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Sjaak Wolfert, Lan Ge, Cor Verdouw, Marc-Jeroen Bogaardt
      Smart Farming is a development that emphasizes the use of information and communication technology in the cyber-physical farm management cycle. New technologies such as the Internet of Things and Cloud Computing are expected to leverage this development and introduce more robots and artificial intelligence in farming. This is encompassed by the phenomenon of Big Data, massive volumes of data with a wide variety that can be captured, analysed and used for decision-making. This review aims to gain insight into the state-of-the-art of Big Data applications in Smart Farming and identify the related socio-economic challenges to be addressed. Following a structured approach, a conceptual framework for analysis was developed that can also be used for future studies on this topic. The review shows that the scope of Big Data applications in Smart Farming goes beyond primary production; it is influencing the entire food supply chain. Big data are being used to provide predictive insights in farming operations, drive real-time operational decisions, and redesign business processes for game-changing business models. Several authors therefore suggest that Big Data will cause major shifts in roles and power relations among different players in current food supply chain networks. The landscape of stakeholders exhibits an interesting game between powerful tech companies, venture capitalists and often small start-ups and new entrants. At the same time there are several public institutions that publish open data, under the condition that the privacy of persons must be guaranteed. The future of Smart Farming may unravel in a continuum of two extreme scenarios: 1) closed, proprietary systems in which the farmer is part of a highly integrated food supply chain or 2) open, collaborative systems in which the farmer and every other stakeholder in the chain network is flexible in choosing business partners as well for the technology as for the food production side. The further development of data and application infrastructures (platforms and standards) and their institutional embedment will play a crucial role in the battle between these scenarios. From a socio-economic perspective, the authors propose to give research priority to organizational issues concerning governance issues and suitable business models for data sharing in different supply chain scenarios.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.023
      Issue No: Vol. 153 (2017)
       
  • Life cycle assessment (LCA) for apple orchard production systems including
           low and high productive years in conventional, integrated and organic
           farms
    • Authors: Y. Goossens; A. Geeraerd; W. Keulemans; B. Annaert; E. Mathijs; J. De Tavernier
      Pages: 81 - 93
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Y. Goossens, A. Geeraerd, W. Keulemans, B. Annaert, E. Mathijs, J. De Tavernier
      Several papers highlight methodological challenges related to the lifecycle assessment (LCA) of fruit production systems. These concern both the limited number of impact categories assessed in current LCA literature and the narrow view on the full production phase of an orchard cycle. This article addresses these challenges and contributes to improving the scientific knowledge on impacts associated with less productive years within an orchard cycle, and how these affect the impact associated with an entire fruit growing cycle. Using apple as a case study, an LCA is performed to obtain the impacts associated with young and old low productive trees, alongside those associated with trees in full production. Using the ILCD impact assessment method, the LCA is based on a large dataset of apple orchards in Flanders (Belgium), covering three production systems (conventional, integrated and organic production) and accounting for input and yield variability. The annual median impact values are used to describe a “typical” orchard for each orchard phase and production system. In conventional farming, lowest annual median impacts are mostly found in the full production phase while highest impacts are observed in the old low productive orchards. In integrated and organic production on the other hand, the lowest annual median impacts mostly occur in the old low productive orchards while highest impacts are found for the young low productive trees. Results for organic farming must however be interpreted with care, following the small sample size of organic producers. To calculate the impacts associated with a full orchard cycle, an orchard model was built based on the annual median impact within each apple bearing orchard phase and production system and using weighting factors based on the yields obtained within each of the orchard phases. Across the three production systems, the two low production phases are responsible for 27 to 38% of the calculated orchard cycle impact. Calculated impacts for the entire orchard cycle are, on average across the impact categories, higher than full production impacts in conventional and integrated farming, while lower in the case of organic farming. A mere focus on high productive trees leads to an underestimation of, on average, 18% in conventional farming and 11% integrated farming, versus an overestimation of 11% for organic farming. Inclusion of non-productive phases such as nursery and planting and destruction of the orchard, would further alter the orchard cycle impacts.

      PubDate: 2017-02-05T19:12:51Z
      DOI: 10.1016/j.agsy.2017.01.007
      Issue No: Vol. 153 (2017)
       
  • Phosphorus dynamics modeling and mass balance in an aquaponics system
    • Authors: B.S. Cerozi; K. Fitzsimmons
      Pages: 94 - 100
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): B.S. Cerozi, K. Fitzsimmons
      Aquacultural effluents are rich in P, a growing concern worldwide for potential environmental pollution. Thus integrating aquaculture with agriculture, e.g. aquaponics, shows promise to enhance nutrient and water use efficiency and overall environmental sustainability. The present study was carried out to quantify a P flow, P mass balance, and evaluate P removal efficiency by hydroponic lettuce integrated with tilapia aquaculture. Also, a phosphorus dynamics simulation model was developed to be a decision support system for phosphorus management. 15 tilapia juveniles (20g) and four 15-day-old lettuce seedlings comprised each aquaponics experimental unit (n=3). At days 0, 7, 14, 21 and 28 after transplanting, water samples were taken from each aquaponics biofilter to determine the reactive and total concentration of phosphorus. The P dynamics model was validated by comparing predicted to observed values of dissolved P over time. The linear regression equations between predicted and measured values were compared with the 1:1 line for statistically significant differences (p<0.05) in slope and intercept values. The adequacy of the model was determined by testing if intercept equals zero and slope equals one separately using the one sample Student t-test. Comparison of simulated and measured values of dissolved P dynamics showed a good fit around the 1:1 line with the slope (b=1.005) and intercept values (a=0.0189) being not statistically different (p>0.05) from 1.0 and 0, respectively. The assimilation of P in the fish and plant components comprised 71.7% of the total P input, indicating high P utilization by the system. The P dynamics model predicted the behavior of dissolved phosphorus in aquaponics systems, which can be used to determine adequate fish:plant ratios, maximize P use efficiency and minimize waste. The overall high P utilization by fish and plants identified in this study showed that aquaponics is an excellent tool for recycling phosphorus while yielding a high-quality crop.

      PubDate: 2017-02-05T19:12:51Z
      DOI: 10.1016/j.agsy.2017.01.020
      Issue No: Vol. 153 (2017)
       
  • Yield comparison of simulated rainfed wheat and barley across Middle-East
    • Authors: Rémy Schoppach; Afshin Soltani; Thomas R. Sinclair; Walid Sadok
      Pages: 101 - 108
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Rémy Schoppach, Afshin Soltani, Thomas R. Sinclair, Walid Sadok
      Rain-fed wheat and barley are key crops in the Middle-East. A slight improvement in the effective use of water and in grain yield could greatly improve lives of subsistence farmers. This study aimed to evaluate the relative merits of wheat and barley in this region by simulating yields across 404 uniformly spread locations across 30 growing seasons. The results emphasized the primary importance of sowing date in each location. In comparison to wheat, barley generally was capable of rapid progress through its development stages allowing it to avoid deleterious late-season droughts and to have greater yields in low rainfall regions. A large part of Middle-East appeared unsuited for rain-fed production of these two grain species if seasonal yield variability is a concern.

      PubDate: 2017-02-05T19:12:51Z
      DOI: 10.1016/j.agsy.2016.12.017
      Issue No: Vol. 153 (2017)
       
  • Impact of alternative cropping systems on groundwater use and grain yields
           in the North China Plain Region
    • Authors: Dengpan Xiao; Yanjun Shen; Yongqing Qi; Juana P. Moiwo; Leilei Min; Yucui Zhang; Ying Guo; Hongwei Pei
      Pages: 109 - 117
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Dengpan Xiao, Yanjun Shen, Yongqing Qi, Juana P. Moiwo, Leilei Min, Yucui Zhang, Ying Guo, Hongwei Pei
      Excessive use of groundwater in irrigation (mainly for production of winter wheat) in the North China Plain (NCP) has resulted in markedly decreased groundwater levels. Alternative cropping systems may have potential to reduce groundwater use in the region. The APSIM (Agricultural Production System Simulator) farming systems model was used to simulate long-term (1981–2015) water use, net overdraft and crop yield for eight cropping systems. The wheat-maize double cropping system (WW–SM) in the study area resulted in overdrafts of 258mmyr−1, about 100mmyr−1 more than estimated groundwater recharge. Although six of eight simulated systems reduced overdrafts below the estimated recharge value of 150mmyr−1, a triple-cropping system consisting of winter wheat/summer maize followed by fallow and early maize (WW–SM/F–EM) in two years appears to be the most viable alternative. Annual grain yield under the triple cropping system was only 13% less than that under the current WW–SM double cropping system. Groundwater overdrafts under triple-cropping system were about equal to lateral recharge from the mountains, water brought in via the South-North Water Transfer (SNWT) project and water from other water-saving measures (e.g. plastic film mulching) in the region.

      PubDate: 2017-02-05T19:12:51Z
      DOI: 10.1016/j.agsy.2017.01.018
      Issue No: Vol. 153 (2017)
       
  • Combined effects of climate change and policy uncertainty on the
           agricultural sector in Norway
    • Authors: Klaus Mittenzwei; Tomas Persson; Mats Höglind; Sigrun Kværnø
      Pages: 118 - 126
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Klaus Mittenzwei, Tomas Persson, Mats Höglind, Sigrun Kværnø
      Farmers are exposed to climate change and uncertainty about how that change will develop. As farm incomes, in Norway and elsewhere, greatly depend on government subsidies, the risk of a policy change constitutes an additional uncertainty source. Hence, climate and policy uncertainty could substantially impact agricultural production and farm income. However, these sources of uncertainty have, so far, rarely been combined in food production analyses. The aim of this study was to determine the effects of a combination of policy and climate uncertainty on agricultural production, land use, and social welfare in Norway. Output yield distributions of spring wheat and timothy, a major forage grass, from simulations with the weather-driven crop models, CSM-CERES-Wheat and, LINGRA, were processed in the a stochastic version Jordmod, a price-endogenous spatial economic sector model of the Norwegian agriculture. To account for potential effects of climate uncertainty within a given future greenhouse gas emission scenario on farm profitability, effects on conditions that represented the projected climate for 2050 under the emission scenario A1B from the 4th assessment report of the Intergovernmental Panel on Climate Change and four Global Climate Models (GCM) was investigated. The uncertainty about the level of payment rates at the time farmers make their management decisions was handled by varying the distribution of payment rates applied in the Jordmod model. These changes were based on the change in the overall level of agricultural support in the past. Three uncertainty scenarios were developed and tested: one with climate change uncertainty, another with payment rate uncertainty, and a third where both types of uncertainty were combined. The three scenarios were compared with results from a deterministic scenario where crop yields and payment rates were constant. Climate change resulted in on average 9% lower cereal production, unchanged grass production and more volatile crop yield as well as 4% higher farm incomes on average compared to the deterministic scenario. The scenario with a combination of climate change and policy uncertainty increased the mean farm income more than a scenario with only one source of uncertainty. On the other hand, land use and farm labour were negatively affected under these conditions compared to the deterministic case. Highlighting the potential influence of climate change and policy uncertainty on the performance of the farm sector our results underline the potential error in neglecting either of these two uncertainties in studies of agricultural production, land use and welfare.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.016
      Issue No: Vol. 153 (2017)
       
  • Towards scientifically based management of extensive livestock farming in
           terms of ecological predator-prey modeling
    • Authors: Francisco Dieguez Cameroni; Hugo Fort
      Pages: 127 - 137
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Francisco Dieguez Cameroni, Hugo Fort
      Grassland production systems have important impact on food supply and in the economy of several countries. In the specific case of Uruguay, located at the Pampa biome, extensive livestock farming represents 80% of the country land use and beef produced in those systems is 90% of the national meat production. Precision livestock production (PLP) or the manipulation of livestock activity taking into account the different components of agroecosystems to improve production has acquired growing importance in recent years within an “ecological intensification” new paradigm. In particular, there has been an increasing interest in applying mathematical modeling to support PLP. Here we develop an integral ecological approach to PLP by modeling the dynamics of the combined grass-animals system as a predator-prey dynamical system or Predator-Prey Grassland Livestock Model (PPGL). The model involves two variables, the grass height and the individual liveweight of animals, as well as the nonlinear interaction between them: animal performance (liveweight) is linked with grass consumption, which depends on forage availability, which in turn is affected by the grazing pressure. To check the PPGL model internal coherence we studied the long-term evolution for its two variables and found oscillations which capture the general observed dynamics both for grass and animal liveweight. From a mathematical point of view this behavior is robust since we show that it corresponds to a frequency locked limit cycle (i.e. forced oscillations). Regarding the quantitative performance of PPGL, the model is able to reproduce known empirical data from extensive grassland farm systems in Uruguay, like the pasture growth rate with a logistic function. Simulations for Basaltic soils of Uruguay resulted in a total production of 3972kg dry matter·ha−1·year−1, with an annual distribution of 20%, 14% 31% and 34% for autumn, winter, spring and summer, respectively. Results for animal liveweight variation, presented a – as expected – high dependence on stocking rate and on initial grass allowance. Winter simulations with low initial grass height (5cm) and high stocking rate (1animal·ha−1) results in a liveweight loss of −0.02kg·animal−1·d−1, whereas spring and summer presented the highest liveweight gain (0.655kg·animal−1·d−1). An annual optimal stocking rate of 0.8Gross Unit·ha−1 for native grassland is supported by short and long-term simulations.
      Graphical abstract image

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.021
      Issue No: Vol. 153 (2017)
       
  • Plant factories; crop transpiration and energy balance
    • Authors: Luuk Graamans; Andy van den Dobbelsteen; Esther Meinen; Cecilia Stanghellini
      Pages: 138 - 147
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Luuk Graamans, Andy van den Dobbelsteen, Esther Meinen, Cecilia Stanghellini
      Population growth and rapid urbanisation may result in a shortage of food supplies for cities in the foreseeable future. Research on closed plant production systems, such as plant factories, has attempted to offer perspectives for robust (urban) agricultural systems. Insight into the explicit role of plant processes in the total energy balance of these production systems is required to determine their potential. We describe a crop transpiration model that is able to determine the relation between sensible and latent heat exchange, as well as the corresponding vapour flux for the production of lettuce in closed systems. Subsequently, this model is validated for the effect of photosynthetic photon flux, cultivation area cover and air humidity on lettuce transpiration, using literature research and experiments. Results demonstrate that the transpiration rate was accurately simulated for the aforementioned effects. Thereafter we quantify and discuss the energy productivity of a standardised plant factory and illustrate the importance of transpiration as a design parameter for climatisation. Our model can provide a greater insight into the energetic expenditure and performance of closed systems. Consequently, it can provide a starting point for determining the viability and optimisation of plant factories.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.003
      Issue No: Vol. 153 (2017)
       
  • Analyzing the economies of crop diversification in rural Vietnam using an
           input distance function
    • Authors: Huy Quynh Nguyen
      Pages: 148 - 156
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Huy Quynh Nguyen
      The farming system in Vietnam is being transformed by integration between a set of cash crops and main food cropping operations. This transformation into diversified farming systems, where smallholders have a production base in rice, can affect output complementarity, technical efficiency, and performance of farms. This study aims to evaluate the economies of crop diversification in rural Vietnam by using the approach of the input distance function. The empirical results reveal that slightly increasing returns to scale are evident in Vietnam's multiple crop production. In addition, the increase in rice production reduces the marginal utilization of inputs for producing other crops. Significant output complementarity is found between rice production and other crops. This finding also implies the potential presence of economies of scope. Another finding is that there is substantial technical inefficiency in multiple-crop farming implying opportunities to expand crop output by 18.7% without greater use of inputs or improved technologies in farm production. The improvement of education, particularly for women and the reduction of the dependency ratio contribute to improving technical efficiency. The estimated result shows that the impact of women's education on technical efficiency is much greater than the impact of men's education. Furthermore, land reforms aimed at the reduction of land fragmentation and proper land rights contribute to improving technical efficiency. Finally, the participation in nonfarm employment and crop diversification are also identified as efficiency policy variables in Vietnam's agricultural development.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.024
      Issue No: Vol. 153 (2017)
       
  • Resource use and economic impacts in the transition from small confinement
           to pasture-based dairies
    • Authors: M. Melissa Rojas-Downing; Timothy Harrigan; A. Pouyan Nejadhashemi
      Pages: 157 - 171
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): M. Melissa Rojas-Downing, Timothy Harrigan, A. Pouyan Nejadhashemi
      In recent years, many livestock farms have transitioned from total confinement housing to a pasture-based system in an effort to reduce labor and production costs and improve profitability. There is a growing interest in biogas recovery among livestock producers to reduce energy costs and manure odors but the economic benefits of anaerobic digestion (AD) on small farms is not well known. A comprehensive analysis was conducted using the Integrated Farm System Model (IFSM), to describe, evaluate and compare the farm performance and economic impacts of representative dairy farms in Michigan transitioning from conventional confinement to seasonal- and pasture-based systems, and evaluate the potential for integration of an AD in the confinement and seasonal pasture systems. The results in farm performance present higher milk production per kilogram of feed in the confinement systems, followed by the seasonal pasture and the annual pasture systems. In the economic analysis, the annual pasture-based system had the greatest net return to management and unpaid factors followed by the seasonal pasture and confinement systems. The addition of an AD on a 100-cow, total confinement dairy decreased the net return to management and unpaid factors by 20%. When anaerobic digestion was added to the seasonal pasture with an increased land base for cash crop production and an imported manure volume equivalent to a 500-cow dairy, the net return to management and unpaid factors increased 269% compared to the seasonal pasture dairy alone.

      PubDate: 2017-02-12T17:04:37Z
      DOI: 10.1016/j.agsy.2017.01.013
      Issue No: Vol. 153 (2017)
       
  • A framework coupling farm typology and biophysical modelling to assess the
           impact of vegetable crop-based systems on soil carbon stocks. Application
           in the Caribbean
    • Authors: Jorge Sierra; François Causeret; Pierre Chopin
      Pages: 172 - 180
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Jorge Sierra, François Causeret, Pierre Chopin
      Agricultural land devoted to vegetable crops in the Caribbean has strongly increased during the past twenty years, which raises major concerns regarding a reduction in soil organic carbon (SOC) stocks because of low C inputs and high SOC outputs from these cropping systems. The aim of this study was to assess the impact of farming practices on SOC stocks at the farm type level. We designed a framework which encompasses a farm typology describing the diversity of farm practices applied to vegetable crops and a model of SOC dynamics to estimate the impact of these practices on SOC stocks. The study was carried out in the Guadeloupe archipelago, which offers a good representation of the variability of Caribbean agriculture, in a context of transition from traditional sugarcane and banana monocultures for export to a more diversified agriculture including vegetable crops. A farm typology was developed from a survey of 71 farmers concerning their socio-economic characteristics and farming practices. The MorGwanik model of SOC dynamics was then used to assess the impact of farming practices on SOC at the farm type level, and to interpret the observed SOC changes. Five farm types were identified varying from traditional export agriculture with low diversification to monoculture of vegetable crops based on compost application and reduced soil tillage. The observed and simulated results indicated that systems with a fallow/vegetables cycle ratio>2 and the monoculture of vegetables including compost applications at ≥10Mgha−1 yr−1 presented C sequestration corresponding to SOC increases of 10% and 3% of the initial stock, respectively. The monoculture of vegetables with a compost rate<10Mgha−1 yr−1 and systems including vegetables in rotation with export crops and a short fallow cycle presented a reduction in SOC that ranged from 10% to 18%. Pedoclimatic conditions had a lower impact on SOC changes. Similar socio-economic profiles of farmers were observed for farm types including very different cropping systems. The model well described SOC changes for each farm type and offered valuable insights about the factors affecting SOC losses and C sequestration. The framework proposed in this study was helpful to identify improved managements that can maintain or increase SOC stocks under tropical conditions.

      PubDate: 2017-02-18T12:25:40Z
      DOI: 10.1016/j.agsy.2017.02.004
      Issue No: Vol. 153 (2017)
       
  • Preliminary analysis on economic and environmental consequences of grain
           production on different farm sizes in North China Plain
    • Authors: Xiaolong Wang; Yuanquan Chen; Peng Sui; Peng Yan; Xiaolei Yang; Wangsheng Gao
      Pages: 181 - 189
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Xiaolong Wang, Yuanquan Chen, Peng Sui, Peng Yan, Xiaolei Yang, Wangsheng Gao
      Due to rapid economic growth and dramatic urbanization in China in the recent 30years, the traditional model for grain production dominated by small-size household farms is gradually being broken, while large-scale farming is becoming increasingly common. However, the information on relationships of environmental and economic consequences of grain production on different farm size has been lacking. In this study, life cycle assessment and economic analysis are used to compare environmental and economic performance of wheat-maize double-cropping system on small, medium and large farm size in North China Plain (NCP). The life cycle assessment indicates that, compared to the small-farm, area-based environmental impact index (EIA) is decreased by 2.4% and 3.4% for the medium-farm and large-farm, yield-based environmental impact index (EIY) is increased by 14.3% for the medium-farm while decreased by 3.4% for the large-farm. The economic analysis shows that the yield-based profits (EPY) for the medium-farm and large-farm are 83.4% and 71.7% lower than that for the small-size farms but the expansion of farm size contributes to the improvement of incomes of workers and owners of the farms together. Generally, the potential environmental impacts of grain production on the same area farmland will possibly change due to the difference of farm size, but expanding farm size will not directly and obviously improve the potential environmental consequences of grain production in the NCP. The larger size farm earns the more net income annually, but the conventional small-farm has the better revenue at the point of yield-based profit. Moreover, a scenario analysis represented that the EIY and EPY for the medium-farm and large-farm would be improved by 1.1%–47.1% and by 11.1–267.3%, respectively, by improved fertilization, irrigation and machines practices. Clearly, the advanced agricultural practice is the key point to improve the environmental and economic consequences for grain production in the NCP. Therefore, it is not scientific to only emphasize the expansion of farm size but, meanwhile, not to promote the implementation of advanced agricultural practices for the environmental and economic consequences of grain production in the NCP.

      PubDate: 2017-02-18T12:25:40Z
      DOI: 10.1016/j.agsy.2017.02.005
      Issue No: Vol. 153 (2017)
       
  • Losses, inefficiencies and waste in the global food system
    • Authors: Peter Alexander; Calum Brown; Almut Arneth; John Finnigan; Dominic Moran; Mark D.A. Rounsevell
      Pages: 190 - 200
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Peter Alexander, Calum Brown, Almut Arneth, John Finnigan, Dominic Moran, Mark D.A. Rounsevell
      Losses at every stage in the food system influence the extent to which nutritional requirements of a growing global population can be sustainably met. Inefficiencies and losses in agricultural production and consumer behaviour all play a role. This paper aims to understand better the magnitude of different losses and to provide insights into how these influence overall food system efficiency. We take a systems view from primary production of agricultural biomass through to human food requirements and consumption. Quantities and losses over ten stages are calculated and compared in terms of dry mass, wet mass, protein and energy. The comparison reveals significant differences between these measurements, and the potential for wet mass figures used in previous studies to be misleading. The results suggest that due to cumulative losses, the proportion of global agricultural dry biomass consumed as food is just 6% (9.0% for energy and 7.6% for protein), and 24.8% of harvest biomass (31.9% for energy and 27.8% for protein). The highest rates of loss are associated with livestock production, although the largest absolute losses of biomass occur prior to harvest. Losses of harvested crops were also found to be substantial, with 44.0% of crop dry matter (36.9% of energy and 50.1% of protein) lost prior to human consumption. If human over-consumption, defined as food consumption in excess of nutritional requirements, is included as an additional inefficiency, 48.4% of harvested crops were found to be lost (53.2% of energy and 42.3% of protein). Over-eating was found to be at least as large a contributor to food system losses as consumer food waste. The findings suggest that influencing consumer behaviour, e.g. to eat less animal products, or to reduce per capita consumption closer to nutrient requirements, offer substantial potential to improve food security for the rising global population in a sustainable manner.
      Graphical abstract image

      PubDate: 2017-02-18T12:25:40Z
      DOI: 10.1016/j.agsy.2017.01.014
      Issue No: Vol. 153 (2017)
       
  • Sustainable intensification of Brazilian livestock production through
           optimized pasture restoration
    • Authors: Rafael de Oliveira Silva; Luis Gustavo Barioni; J. A. Julian Hall; Antonio Carlos Moretti; Rui Fonseca Veloso; Peter Alexander; Mariane Crespolini; Dominic Moran
      Pages: 201 - 211
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Rafael de Oliveira Silva, Luis Gustavo Barioni, J. A. Julian Hall, Antonio Carlos Moretti, Rui Fonseca Veloso, Peter Alexander, Mariane Crespolini, Dominic Moran
      Grassland degradation compromises the profitability of Brazilian livestock production, and pasture recovery is a promising strategy for sustainable intensification of agriculture (SAI). Recovery increases carbon sequestration into the soil and can potentially avoid deforestation; thereby reducing emissions intensity (EI), but only at increased investment cost per unit of area. We develop a multi-period linear programming (LP) model for grazing beef production planning to represent a typical Cerrado stocking and finishing beef farm. We compare economic and environmental performance of two alternative optimized pasture management approaches relative to the traditional practice (TRP), which is based on restoring pasture after a full degradation cycle of 8years. The scenarios considered the difference made by access to subsidized credit through the Low Carbon Agriculture program (“Programa ABC”). The model estimates EI using upstream life cycle assessment (LCA), and dynamically estimates soil organic carbon (SOC) changes as a function of pasture management. The results show net present values (NPV) ranging from −67 Brazilian reals per hectare-year (R$·ha−1·yr−1) to around 300 R$·ha−1·yr−1, respectively for traditional and optimized pasture management strategies. Estimated EI of the TRP is 9.26 kgCO2 equivalent per kg of carcass weight equivalent (kgCO2e/kg CWE) relative to 3.59kgCO2e/kg CWE for optimized management. Highest emission abatement results from improved SOC sequestration, while access to credit could further reduce EI by around 20%. We consider the effects of alternative credit interest on both NPV and EI. The results provide evidence to inform the design of Brazil's key domestic policy incentive for low carbon agriculture, which is an important component of the country's Intended Nationally Determined Contributions (INDC) on emissions mitigation. The results also contribute to the global debate on the interpretation of SAI.

      PubDate: 2017-02-24T17:22:20Z
      DOI: 10.1016/j.agsy.2017.02.001
      Issue No: Vol. 153 (2017)
       
  • Assessing the harvested area gap in China
    • Authors: Qiangyi Yu; Wenbin Wu; Liangzhi You; Tingju Zhu; Jasper van Vliet; Peter H. Verburg; Zhenhuan Liu; Zhengguo Li; Peng Yang; Qingbo Zhou; Huajun Tang
      Pages: 212 - 220
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Qiangyi Yu, Wenbin Wu, Liangzhi You, Tingju Zhu, Jasper van Vliet, Peter H. Verburg, Zhenhuan Liu, Zhengguo Li, Peng Yang, Qingbo Zhou, Huajun Tang
      Total crop production is a function of the harvested area and the yield. Many studies have investigated opportunities to increase production by closing the yield gap and by expanding cropland area. However, the potential to increase the harvested area by increasing the cropping frequency on existing cropland has remained largely unexplored. Our study suggests that the attainable harvested area gap (HAG) in China ranges from 13.5 to 36.3 million ha, depending on the selected water allocation scenario, relative to the current harvested area of 160.0 million ha. Spatially, South China and the Lower Yangtze region have the largest potential to increase harvested area, as these regions allow triple-cropping, have sufficient water available, and have a good irrigation infrastructure. The results imply that management factors are equally important for exploring the potential against the resource endowment: water allocation has a large impact on both the size and the spatial pattern of the attainable HAG. This indicates the necessity of further examining the spatial-temporal dynamics of HAG at national and regional scales, and its potential contribution to food security and sustainable agricultural development.

      PubDate: 2017-02-24T17:22:20Z
      DOI: 10.1016/j.agsy.2017.02.003
      Issue No: Vol. 153 (2017)
       
  • Understanding the role of social capital in adoption decisions: An
           application to irrigation technology
    • Authors: Claudia Hunecke; Alejandra Engler; Roberto Jara-Rojas; P. Marijn Poortvliet
      Pages: 221 - 231
      Abstract: Publication date: May 2017
      Source:Agricultural Systems, Volume 153
      Author(s): Claudia Hunecke, Alejandra Engler, Roberto Jara-Rojas, P. Marijn Poortvliet
      Recently, social capital has gained importance in explaining technology adoption decisions by farmers. In this paper, we examine the impact of social capital on the adoption of irrigation technology and irrigation scheduling among wine producers in Central Chile. We propose three hypotheses: that trust and networks affect positively the adoption of both technologies (H1 and H2) and that trust is positively related to networks (H3). First, we identify seven different components of social capital: general trust, trust in institutions, trust in water communities, norms, formal networks, informal networks, and size of networks. Second, we estimate two Partial Least Squares models using as endogenous variables irrigation technology adoption and adoption of irrigation scheduling. Both models tested confirm the relevance of our interpretation of the use of social capital and its implications in understanding producers' behaviour towards adoption of technologies. The three hypotheses tested positive. Trust in institutions, and formal and informal networks have a positive impact on the adoption of both technologies. General trust has a positive relationship with formal and informal networks. Human capital also has a strong relationship with networks, which allows us to argue that networks are the main catalysts of social capital. As expected, physical and human capital have a positive and significant relationship with adoption. Our results support that extension efforts should consider social networks, not just economic or individual-level predictors, in promoting agricultural innovations.

      PubDate: 2017-03-04T05:50:03Z
      DOI: 10.1016/j.agsy.2017.02.002
      Issue No: Vol. 153 (2017)
       
  • Impact of climate change on farms in smallholder farming systems: Yield
           impacts, economic implications and distributional effects
    • Authors: Lemlem Teklegiorgis Habtemariam; Getachew Abate Kassa; Markus Gandorfer
      Pages: 58 - 66
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Lemlem Teklegiorgis Habtemariam, Getachew Abate Kassa, Markus Gandorfer
      The impact of climate change on farms can be determined by factors such as local climatic changes, farm physical environment, the type of crops grown, and household socio-economic characteristics that limit or increase adaptability to climate change. The current study assesses the impacts of climate and socio-economic changes on smallholder farms in two districts of Ethiopia representing different agro-ecology in a major agricultural region. For this purpose, observed farm production data, simulated yield under climate change and socio-economic scenarios were used. The aim was to produce information that facilitates an understanding of the unequal economic implications of climate change on farms. To this end, the study applied the Tradeoff Analysis for Multi-Dimensional impact assessment (TOA-MD) economic simulation model in combination with the AquaCrop yield simulation model. The findings on climate change impact towards 2030 highlight the uneven implications of climate change on farms and the role that agro-ecology and future socio-economic development scenarios play in determining climate change impact. It is found that, under the climate projections we considered crops such as tef, barley and wheat are found to benefit from the projected climate change in cool regions. In warm regions, tef and wheat are projected to be negatively affected whereas maize would benefit. The proportion of farms that are negatively affected by climate change ranged between 51% and 78% in warm regions under different scenarios; in cool regions, the proportion of negatively affected farms ranged between 10% and 22%. The implications of climate change are found to vary under various socio-economic scenarios, in which positive socio-economic scenarios considerably reduced the proportion of negatively affected farms. The economic implications of climate change also found to differ among farms within agro-ecology because of differences in land allocation to various crops that have different sensitivity to climate change, and due to other farm differences. Thus, the study shows the importance of using farm and site-specific production and climate data to reveal variabilities in climate change impact. It also provides evidence on the relevance of accounting for agro-ecology and crop differences as well as consideration of potential socio-economic changes. Overall, the results suggest that appropriate agricultural interventions that recognize location and crop differences are essential to minimize climate change impact.

      PubDate: 2017-01-06T20:36:39Z
      DOI: 10.1016/j.agsy.2016.12.006
      Issue No: Vol. 152 (2017)
       
  • Climate change and dryland wheat systems in the US Pacific Northwest
    • Authors: T. Karimi; C.O. Stöckle; S. Higgins; R. Nelson
      Abstract: Publication date: Available online 6 April 2017
      Source:Agricultural Systems
      Author(s): T. Karimi, C.O. Stöckle, S. Higgins, R. Nelson
      A regional assessment of baseline (1980–2010) and future (2015–2085) yields of dryland wheat-based cropping systems in the US Inland Pacific Northwest (IPNW) was conducted. The computer simulation-based assessment was done using CropSyst, a cropping systems simulation model, and projected daily weather data downscaled to a 4×4km grid using 12 general circulation models (GCMs) for two atmospheric CO2 representative concentration pathways (RCP 4.5 and RCP 8.5). The study region was divided into 3 agro-ecological zones (AEZs): continuous cropping (CC), continuous cropping-fallow transition (CCF), and crop-fallow (CF), with the following typical rotations assigned to the zones: winter wheat (WW) – summer fallow (SF) (CF zone), WW – spring wheat (SW) – SF (CCF zone), and WW – SW – spring pea (CC zone). By the 2070s (2065–2085), precipitation in the IPNW is projected to increase by about 8 and 12% compared to the baseline period under RCP 4.5 and 8.5, respectively. Mean temperature during the WW growing season will increase about 1.5 and 2.3°C under RCP 4.5 and 8.5, respectively, but will not change noticeably during the SW growing season due to the adaptive early planting used in this study. Concurrently, atmospheric CO2 concentration will increase from today's average of ~400ppm to 532ppm to 801ppm by 2085 depending on future emissions of greenhouse gases. Soil water-crop growth interactions, which show large variation across the region, will modulate crop responses to these changing conditions, with our results showing an overall increase in yield across the IPNW. By the 2070s, the mean ratio of future to baseline WW yield will range from 1.29 to 1.35 under RCP 4.5 and from 1.41 to 1.64 under RCP 8.5 depending on the AEZ. The mean yield ratio for SW across AEZs will range from 1.38 to 1.53 under RCP 4.5 and 1.54 to 1.91 under RCP 8.5. Given substantial climatic heterogeneity in the region, these gains will not be distributed equally across the region or within AEZs, and overall they will not be shared equally by all growers.

      PubDate: 2017-04-11T18:44:05Z
      DOI: 10.1016/j.agsy.2017.03.014
       
  • Climate change impact under alternate realizations of climate scenarios on
           maize yield and biomass in Ghana
    • Authors: Amit Kumar Srivastava; Cho Miltin Mboh; Gang Zhao; Thomas Gaiser; Frank Ewert
      Abstract: Publication date: Available online 31 March 2017
      Source:Agricultural Systems
      Author(s): Amit Kumar Srivastava, Cho Miltin Mboh, Gang Zhao, Thomas Gaiser, Frank Ewert
      Climate change is unequivocal and these changes have increased over the past few years. The recent vulnerability and prospect of climate variability and change impact, thus, warrants measures now to reduce the adverse impacts. This study presents an estimate of the effects of climate variables on potential maize productivity and an assessment of the most limiting climatic drivers in the future climate scenarios for maize production in central Ghana, constituting major maize production areas. The time-slices 2000, 2030 and 2080 were chosen to represent the baseline, near future and end century climate, respectively. Furthermore, two Representative Concentration Pathways (RCPs) namely RCP 4.5 and RCP 8.5 from the GFDL-ESM2M, GISS-E2-H, and HadGEM2-ES, General Circulation Models (GCMs), were selected. Simulations based on the model LINTUL5 were used to estimate the crop responses. There is an average increase in the maize yield and aboveground biomass in the projected scenarios by 57% and 59% respectively under HadGEM2-ES (RCP 8.5) in the time horizon 2030. However, variability in the projected average maize yield and above ground biomass compared to the baseline values, is ranging from 183.6kgha−1 under HadGEM2-ES (RCP 8.5) by time horizon 2080 to a maximum of 1326.8kgha−1 under HadGEM2-ES (RCP 8.5) by 2030 and a minimum increase of 169.9kgha−1 under GFDL-ESM2M (RCP 8.5) by time horizon 2080 to a maximum increase of 2386.1kgha−1 under HadGEM2-ES (RCP 8.5) by time horizon 2030. The reasons for potential benefit in maize yields across the climate scenarios was attributed to the positive effect of CO2, reduced water stress reflected by lower atmospheric water demand during crop growth period. It also indicates that water is the limiting factor for maize production in the study region. However, temperature (through shortening of the maize growing cycle), and solar radiation may remain the limiting factors for maize production.

      PubDate: 2017-04-05T10:51:41Z
      DOI: 10.1016/j.agsy.2017.03.011
       
  • Agricultural intensification scenarios, household food availability and
           greenhouse gas emissions in Rwanda: Ex-ante impacts and trade-offs
    • Authors: B.K. Paul; R. Frelat; C. Birnholz; C. Ebong; A. Gahigi; J.C.J. Groot; M. Herrero; D.M. Kagabo; A. Notenbaert; B. Vanlauwe; M.T. van Wijk
      Abstract: Publication date: Available online 8 March 2017
      Source:Agricultural Systems
      Author(s): B.K. Paul, R. Frelat, C. Birnholz, C. Ebong, A. Gahigi, J.C.J. Groot, M. Herrero, D.M. Kagabo, A. Notenbaert, B. Vanlauwe, M.T. van Wijk
      Rwanda's agricultural sector is facing severe challenges of increasing environmental degradation, resulting in declining productivity. The problem is likely to be further aggravated by the growing population pressure. A viable pathway is climate smart agriculture, aiming at the triple win of improving food security and climate change adaptation, while contributing to mitigation if possible. The Government of Rwanda has initiated ambitious policies and programs aiming at low emission agricultural development. Crop focused policies include the Crop Intensification Program (CIP) which facilitates access to inorganic fertilizer and improved seeds. In the livestock subsector, zero-grazing and improved livestock feeding are encouraged, and the Girinka program provides poor farm households with a crossbred dairy cow. In this study, we aimed at assessing the potential impact of these policy programs on food availability and greenhouse gas (GHG) emissions of 884 households across different agro-ecologies and farming systems in Rwanda. Household level calculations were used to assess the contribution of current crops, livestock and off-farm activities to food availability and GHG emissions. Across all sites, 46% of households were below the 2500kcalMAE−1 yr−1 line, with lower food availability in the Southern and Eastern Rwanda. Consumed and sold food crops were the mainstay of food availability, contributing between 81.2% (low FA class) to 53.1% (high FA class). Livestock and off-farm income were the most important pathways to higher FA. Baseline GHG emissions were low, ranging between 395 and 1506kg CO2e hh−1 yr−1 per site, and livestock related emissions from enteric fermentation (47.6–48.9%) and manure (26.7–31.8%) were the largest contributors to total GHG emissions across sites and FA classes. GHG emissions increased with FA, with 50% of the total GHG being emitted by 22% of the households with the highest FA scores. Scenario assessment of the three policy options showed strong differences in potential impacts: Girinka only reached one third of the household population, but acted highly pro-poor by decreasing the households below the 2500kcalMAE−1 yr−1 line from 46% to 35%. However, Girinka also increased GHG by 1174kg CO2e hh−1 yr−1, and can therefore not be considered climate-smart. Improved livestock feeding was the least equitable strategy, decreasing food insufficient households by only 3%. However, it increased median FA by 755kcalMAE−1 yr−1 at a small GHG increase (50kg CO2e hh−1 yr−1). Therefore, it is a promising option to reach the CSA triple win. Crop and soil improvement resulted in the smallest increase in median FA (FA by 755kcalMAE−1 yr−1), and decreasing the proportion of households below 2500kcalMAE−1 yr−1 by 6%. This came only at minimal increase in GHG emissions (23kg CO2e hh−1 yr−1). All policy programs had different potential impacts and trade-offs on different sections of the farm household population. Quick calculations like the ones presented in this study can assist in policy dialogue and stakeholder engagement to better select and prioritize policies and development programs, despite the complexity of its impacts and trade-offs.

      PubDate: 2017-03-09T13:17:04Z
      DOI: 10.1016/j.agsy.2017.02.007
       
  • Assessing future meteorological stresses for grain maize in France
    • Authors: J. Caubel; I. Garcia de Cortazar-Atauri; A.C. Vivant; M. Launay; N. de Noblet-Ducoudré
      Abstract: Publication date: Available online 3 March 2017
      Source:Agricultural Systems
      Author(s): J. Caubel, I. Garcia de Cortazar-Atauri, A.C. Vivant, M. Launay, N. de Noblet-Ducoudré
      Recent climate change has already affected maize cropping in France allowing for example earlier sowing dates in southern France and the growth of early season varieties in northern parts of the country. The climate will continue to evolve as discussed in all IPCC reports and there is a need for farmers, seed companies and agricultural cooperative corporations to be able to anticipate those changes. The ambition of our work is to provide them with the means to get ready to adapt by analyzing a) the time evolution of meteorological stresses and certain management practices throughout the crop's growth cycle, b) the impacts of climate-induced changes in calculated sowing dates on those stresses and practices. We have applied the method we developed in a former paper to study the climatic suitability of maize in two contrasted areas of France, Ile-de-France in the North and Midi-Pyrénées in the South. Three climate change scenarios, two climate models and two maize varieties distinct in terms of precocity were used to try and ensure meaningful results. Whatever the scenario, model and variety, maize will be sown earlier than it is currently the case in both regions, especially in Midi-Pyrénées. Whatever the sowing date, rising temperatures in the future will be favorable for late varieties in the current cooler areas, and therefore even farmers in Ile-de-France will be able to grow varieties with a wide range of crop cycle length. However heat and water stress will increase in both regions between flowering and maturity, irrespective of the sowing date and scenario, thereby limiting the possibility to achieve potential yields. In Midi-Pyrénées compromises will need to be found between early sowing to minimize some later stress and increasing risks of frost during emergence, that do not currently exist.

      PubDate: 2017-03-04T05:50:03Z
      DOI: 10.1016/j.agsy.2017.02.010
       
  • Mapping of beef, sheep and goat food systems in Nairobi — A framework
           for policy making and the identification of structural vulnerabilities and
           deficiencies
    • Authors: Pablo Alarcon; Eric M. Fèvre; Maurice K. Murungi; Patrick Muinde; James Akoko; Paula Dominguez-Salas; Stella Kiambi; Sohel Ahmed; Barbara Häsler; Jonathan Rushton
      Pages: 1 - 17
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Pablo Alarcon, Eric M. Fèvre, Maurice K. Murungi, Patrick Muinde, James Akoko, Paula Dominguez-Salas, Stella Kiambi, Sohel Ahmed, Barbara Häsler, Jonathan Rushton
      Nairobi is a large rapidly-growing city whose demand for beef, mutton and goat products is expected to double by 2030. The study aimed to map the Nairobi beef, sheep and goat systems structure and flows to identify deficiencies and vulnerabilities to shocks. Cross-sectional data were collected through focus group discussions and interviews with people operating in Nairobi ruminant livestock and meat markets and in the large processing companies. Qualitative and quantitative data were obtained about the type of people, animals, products and value adding activities in the chains, and their structural, spatial and temporal interactions. Mapping analysis was done in three different dimensions: people and product profiling (interactions of people and products), geographical (routes of animals and products) and temporal mapping (seasonal fluctuations). The results obtained were used to identify structural deficiencies and vulnerability factors in the system. Results for the beef food system showed that 44–55% of the city's beef supply flows through the ‘local terminal markets’, but that 54–64% of total supply is controlled by one ‘meat market’. Numerous informal chains were identified, with independent livestock and meat traders playing a pivotal role in the functionality of these systems, and where most activities are conducted with inefficient quality control and under scarce and inadequate infrastructure and organisation, generating wastage and potential food safety risks in low quality meat products. Geographical and temporal analysis showed the critical areas influencing the different markets, with larger markets increasing their market share in the low season. Large processing companies, partly integrated, operate with high quality infrastructures, but with up to 60% of their beef supply depending on similar routes as the informal markets. Only these companies were involved in value addition activities, reaching high-end markets, but also dominating the distribution of popular products, such as beef sausages, to middle and low-end market. For the small ruminant food system, 73% of the low season supply flows through a single large informal market, Kiamaiko, located in an urban informal settlement. No grading is done for these animals or the meat produced. Large companies were reported to export up to 90% of their products. Lack of traceability and control of animal production was a common feature in all chains. The mapping presented provides a framework for policy makers and institutions to understand and design improvement plans for the Nairobi ruminant food system. The structural deficiencies and vulnerabilities identified here indicate the areas of intervention needed.

      PubDate: 2016-12-19T16:29:38Z
      DOI: 10.1016/j.agsy.2016.12.005
      Issue No: Vol. 152 (2016)
       
  • The role and value of diverse sward mixtures in dairy farm systems of New
           Zealand: An exploratory assessment
    • Authors: Alvaro J. Romera; Graeme J. Doole; Pierre C. Beukes; Norman Mason; Paul L. Mudge
      Pages: 18 - 26
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Alvaro J. Romera, Graeme J. Doole, Pierre C. Beukes, Norman Mason, Paul L. Mudge
      New Zealand dairy farm systems mostly rely on ryegrass-white clover pastures. The inclusion of diverse sward mixtures within these systems offers a novel strategy to improve economic and environmental outcomes. However, the degree to which these mixtures offer advantages over traditional pastures is unknown. This analysis seeks to explore the role and value of diverse mixtures to New Zealand dairy farms, through integrating the results of recent experimental research involving diverse sward mixtures with an existing whole-farm model. An exploratory assessment is required to determine further investment in these species, guide further data collection and experimental design, and understand traits of high value to farming systems. Model output suggests that the economic incentives associated with the use of diverse swards are too weak on their own to motivate wide-scale adoption under standard conditions. This finding is highly robust to changes in the milk price. However, given societal concern pertaining to water-quality deterioration, reductions in the levels of nitrogen lost from dairy farms are found to add substantially to the value proposition offered by alternative sward species. Reductions in nitrogen leaching of about 40% were predicted here when all the sward area on the farm is sown to diverse sward mixtures, compared with standard mixtures. This is mainly derived from a reduction in the concentration of nitrogen present in urine, and to a much lesser extent by a reduction in the total amount of urinary nitrogen excreted by cows. Overall, diverse swards appear to be a cost-effective way to reduce nitrogen leaching, which is relevant for a dairy sector facing regulatory constraints. Nevertheless, the need to understand and improve the persistence of diverse swards is important to reduce the cost of pasture establishment.

      PubDate: 2016-12-19T16:29:38Z
      DOI: 10.1016/j.agsy.2016.12.004
      Issue No: Vol. 152 (2016)
       
  • An efficiency-based concept to assess potential cost and greenhouse gas
           savings on German dairy farms
    • Authors: Patrick Johannes Christopher Wettemann; Uwe Latacz-Lohmann
      Pages: 27 - 37
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Patrick Johannes Christopher Wettemann, Uwe Latacz-Lohmann
      This article investigates potential savings of costs and greenhouse gas (GHG) emissions for a sample of 216 dairy farms in northern Germany using Data Envelopment Analysis. Tradeoffs between a cost-efficient and a GHG-efficient production are identified. For this purpose, an environmental-economic farm model is used, which allows ‘pricing’ the input with market prices and CO2 equivalents, respectively. Uncertainty of CO2 equivalents and volatility of input prices are taken into account and therefore efficiency scores are in the form of ranges. The results reveal that the sample farms are more GHG-efficient than cost-efficient. We estimate potential cost savings between 37.2% and 57.4% and potential savings in GHG emissions between 24.9% and 41.3%. Cost and GHG emission reductions are complementary across a wide range: by moving from the status quo to cost-efficient production, at least 87.5% of the GHG saving potential would be tapped. Unlocking the remaining reduction potential comes at a shadow price (abatement cost) of about €165/t CO2 equivalent. From an input allocative point of view, a change from cost-efficient production to GHG-efficient production requires reductions in nitrogen use and an extension of diesel use. Compared to the sample average and the cost-efficient farms, GHG efficient dairy farms are characterized by a higher share of legumes and a longer effective lifetime of cows.

      PubDate: 2016-12-27T03:25:18Z
      DOI: 10.1016/j.agsy.2016.11.010
      Issue No: Vol. 152 (2016)
       
  • Comparison of greenhouse gas emissions from corn- and barley-based dairy
           production systems in Eastern Canada
    • Authors: Jessie Guyader; Shannan Little; Roland Kröbel; Chaouki Benchaar; Karen A. Beauchemin
      Pages: 38 - 46
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Jessie Guyader, Shannan Little, Roland Kröbel, Chaouki Benchaar, Karen A. Beauchemin
      In Canada, corn silage is increasingly fed to lactating dairy cows at the expense of barley silage and other forages, as its high-energy content can improve animal performance. Moreover, corn silage is known to reduce methanogenesis in the rumen compared to barley silage. A life cycle analysis was conducted to compare whole farm total GHG emission and greenhouse gas (GHG) intensity (kilogram CO2-equivalent per kilogram of milk) of corn- (CS) and barley- (BS) based dairy production systems. For this purpose, a virtual farm representative of typical dairy production systems in Quebec was used to simulate the 6-year lifespan of a dairy cow, from calving to culling. Diets fed to lactating cows consisted of 54.4% corn or barley silage, 5.5% grass hay and 40.1% concentrate (dry matter basis). The impact of silage digestibility (measured as total digestible nutrient [TDN] content) on total GHG emissions of the dairy production system was also assessed. From prior experimental data, milk production was assumed to average 34.7 and 31.9kg/day for lactating cows fed corn and barley silages of medium TDN content respectively. Milk production was also assumed to be positively correlated with the TDN content of diets. To compensate for differences in milk production per cow, the number of cows was adjusted to obtain similar total fat- and protein-corrected milk production between farms. Forage (silage and hay) and grain (barley or corn) were cultivated on-farm whereas all other feed ingredients were purchased. Greenhouse gas emissions were estimated with the Holos model using a “cradle-to-farm gate” approach. Methane (enteric fermentation and manure storage), CO2 (farm operations, production and transportation of purchased feed) and N2O (N degradation from crop residue, manure, N leaching and volatilization) emissions were taken into account. Enteric CH4 was predicted from animal energy requirements and diet composition. Percentage of energy intake lost as CH4 was assumed constant regardless of silage TDN content. When silages having medium TDN content were used, total GHG emission was reduced by 13% with CS compared to BS, despite the fact that the reduction of enteric CH4 emissions with corn silage was partially offset by increased CO2 emissions from the additional purchased feed protein sources (+9%). Within a forage type, increasing silage TDN content reduced GHG intensity. Finally, the GHG intensity of dairy production systems was lower with high digestible barley silage compared to low digestible corn silage showing the importance of producing forages with high digestibility that maximize milk production.
      Graphical abstract image

      PubDate: 2016-12-27T03:25:18Z
      DOI: 10.1016/j.agsy.2016.12.002
      Issue No: Vol. 152 (2016)
       
  • Detecting spatial variability of paddy rice yield by combining the DNDC
           model with high resolution satellite images
    • Authors: Quanying Zhao; Sebastian Brocks; Victoria I.S. Lenz-Wiedemann; Yuxin Miao; Fusuo Zhang; Georg Bareth
      Pages: 47 - 57
      Abstract: Publication date: March 2017
      Source:Agricultural Systems, Volume 152
      Author(s): Quanying Zhao, Sebastian Brocks, Victoria I.S. Lenz-Wiedemann, Yuxin Miao, Fusuo Zhang, Georg Bareth
      Yield estimation over large areas is critical for ensuring food security, guiding agronomical management, and designing national and international food trade strategies. Besides, analyzing the impacts of managed cropping systems on the environment is important for sustainable agriculture. In this study, the agro-ecosystem model DNDC (DeNitrification-DeComposition) and FORMOSAT-2 (FS-2) satellite imagery were used to detect spatial variabilities of paddy rice yield in the Qixing Farm in 2009. The Qixing Farm is located at the center of the Sanjiang Plain in north-east China, which is one of the important national food bases of China. The site-specific mode of the DNDC model was adapted due to its advantages of better transferability and flexibility. It was generalized onto a regional scale by programming a set of scripts using the Python programming language. Soil data were prepared as model inputs in 100m raster files. The spatial variabilities in modelled yields were well detected based on the detailed soil data and an accurate rice area map. Rice yield was also derived from multiple vegetation indices based on the FS-2 imagery. The DNDC model integrates environmental factors and predicts yield depending on all model input data, whereas the RS method mainly considers in-season crop information. Based on the vegetation indices, the RS-derived yield represents a response to the environmental factors and human activities which may exceed the DNDC capability. It was found that the highest coefficient of model determination (CD) and index of agreement (IA) for the modelled yield were 2.63 and 0.74, respectively, while for the RS-derived yield, the highest CD and IA were 1.2 and 0.55, respectively. Results from both methods were comparable and each method has its own advantages.

      PubDate: 2016-12-27T03:25:18Z
      DOI: 10.1016/j.agsy.2016.11.011
      Issue No: Vol. 152 (2016)
       
 
 
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