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Publisher: Elsevier   (Total: 3049 journals)

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Showing 1 - 200 of 3089 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 7)
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 25, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 86, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 30, 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: 363, 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   (Followers: 1)
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: 229, 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: 10, 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: 1)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 24, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, 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: 4, 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)
Acute Pain     Full-text available via subscription   (Followers: 13)
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: 6)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 21)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 133, 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: 17, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 9, 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: 26, 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: 11, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22, 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: 25, 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 Cell Aging and Gerontology     Full-text available via subscription   (Followers: 4)
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: 27, 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: 9, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 29, 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 Dermatology     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 7)
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: 45, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 26, 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: 43, 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: 51, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
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: 22, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
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: 36, 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: 6)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
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: 6, 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: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 8, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
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: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, 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: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 62)
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: 2, SJR: 0.1, h-index: 2)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 361, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 7, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 30, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 16)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 44, 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: 331, 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: 5, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 8, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 417, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 16, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 30, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 40, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 2)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 55, 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: 5, 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: 11, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 8)
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   (Followers: 1)
Algal Research     Partially Free   (Followers: 8, 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: 4, SJR: 0.776, h-index: 35)
Alpha Omegan     Full-text available via subscription   (SJR: 0.121, h-index: 9)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 46, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 49, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 48, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 40, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 9, 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: 26, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 32, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 46, 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: 199, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 59, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6)
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: 25, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 25, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 35, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 58, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 12)
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: 4, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 37, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 167, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 8, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 12)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  

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Journal Cover Agriculture, Ecosystems & Environment
  [SJR: 1.879]   [H-I: 120]   [55 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0167-8809 - ISSN (Online) 1873-2305
   Published by Elsevier Homepage  [3049 journals]
  • The significance of climate in the pollinator dynamics of a tropical
           agroforestry system
    • Authors: S.E.J. Arnold; P. Bridgemohan; G.B. Perry; G.R. Spinelli; B. Pierre; F. Murray; C. Haughton; O. Dockery; L. Grey; S.T. Murphy; S.R. Belmain; P.C. Stevenson
      Pages: 1 - 9
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): S.E.J. Arnold, P. Bridgemohan, G.B. Perry, G.R. Spinelli, B. Pierre, F. Murray, C. Haughton, O. Dockery, L. Grey, S.T. Murphy, S.R. Belmain, P.C. Stevenson
      Even though many globally important tropical agroforestry crops are partially or completely dependent on insect pollination, the conditions influencing pollinator abundance in these systems are often incompletely understood. This is particularly the case for cocoa midges (Diptera: Ceratopogonidae), which are essential for cocoa pollination and thus yield, but agro-ecological management frequently neglects them. We report the first assessment of cocoa midge population dynamics from two Caribbean countries across a full year, and relate this to seasonal climate variables. We used static suction traps along transects to sample insects monthly, from six cocoa farms across three Caribbean islands, with a particular focus on known pollinators of cocoa. A total of over 87,000 insects were captured, including more than 1800 cocoa midges. Midges were present in all months of the survey and on all sites, but typically comprised less than 2% of the total insects caught. At least twelve different species of cocoa midges were identified from this survey. The previous month’s rainfall positively predicted cocoa midge absolute abundance and further analysis also revealed a relationship between rainfall and relative midge abundance. In particular, during drought periods, midge numbers were very low, consistent with their larval ecology. Humidity and mean daily maximum and minimum temperatures did not relate to midge abundance. Rainfall negatively influenced the Shannon-Weaver index. The findings highlight the possible threat of droughts to cocoa pollination services and the importance of proactive farm management to support them.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.013
      Issue No: Vol. 254 (2017)
       
  • Tea planting affects soil acidification and nitrogen and phosphorus
           distribution in soil
    • Authors: Peng Yan; Chen Shen; Lichao Fan; Xin Li; Liping Zhang; Lan Zhang; Wenyan Han
      Pages: 20 - 25
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Peng Yan, Chen Shen, Lichao Fan, Xin Li, Liping Zhang, Lan Zhang, Wenyan Han
      Land use change from natural forest to agricultural land often affects the properties of soil, resulting in various environmental problems. A field study was conducted to evaluate the effects of land use change from forest to tea cultivation on soil acidification as well as the nitrogen (N) and phosphorus (P) leaching risk. The soil acidification and nutrient concentrations in soil at a depth of 0–200cm in two tea gardens with differing stand ages (10 and 100 years old), and three different fertilizer input levels (low-input, medium-input, and high-input), and in the forests adjacent to these tea gardens were measured at the Tea Research Institute of the Chinese Academy of Agricultural Sciences. Tea cultivation caused soil acidification throughout the 0–200cm soil profile, and the lowest soil pH was observed in the 20–40 or 40–60cm soil depth. Both nitrate (NO3 −) and ammonia (NH4 +) concentrations increased as the tea stand age and fertilizer input levels increased at the 0–90cm soil depth. Compared to the forests, significantly higher concentrations of NO3 − and NH4 + were observed in the 90–200cm soil of the tea gardens, suggestive of a high risk of N leaching loss in the tea gardens. Longer tea cultivation times and higher input levels also increased the concentration of soil available P and CaCl2-P at 0–90cm soil depth, and a change point was observed in the relationship between soil available P and CaCl2-P. Depending on the relationship between soil available P and soil CaCl2-P, the soil CaCl2-P concentration dramatically increased when soil available P surpassed 75.1mgkg−1. This study also indicated that soil acidification could occur in deep soil profiles as a result of tea cultivation and excessive fertilization; thus, there is a high risk of N and P leaching loss in tea gardens.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.015
      Issue No: Vol. 254 (2017)
       
  • Adaptation of the century model to simulate C and N dynamics of Caatinga
           dry forest before and after deforestation
    • Authors: Tiago Diniz Althoff; Rômulo Simões Cezar Menezes; Alexandre de Siqueira Pinto; Frans Germain Corneel Pareyn; André Luiz de Carvalho; Júlio César Rodrigues Martins; Eric Xavier de Carvalho; Antonio Samuel Alves da Silva; Emmanuel Damilano Dutra; Everardo Valadares de Sá Barretto Sampaio
      Pages: 26 - 34
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Tiago Diniz Althoff, Rômulo Simões Cezar Menezes, Alexandre de Siqueira Pinto, Frans Germain Corneel Pareyn, André Luiz de Carvalho, Júlio César Rodrigues Martins, Eric Xavier de Carvalho, Antonio Samuel Alves da Silva, Emmanuel Damilano Dutra, Everardo Valadares de Sá Barretto Sampaio
      About half of the original one million km2 originally covered by the tropical dry forest of northeastern Brazil (known as “Caatinga”), has been deforested and replaced by crops and pastures. The remaining forest is constantly subjected to firewood removal. Besides that, pastures and cropping fields are often abandoned after a few years, allowing regeneration of secondary forest patches. These patterns create a mosaic of land use types and dry forest fragments under different regeneration stages, but there is little information about biogeochemical cycling in this ecosystem. Understanding the impacts of these changes, especially on carbon and nitrogen cycling, is important to define appropriate policies to preserve soils and vegetation and to contribute to reduce emissions and remove carbon from the atmosphere. Generating data about these processes require monitoring of large areas for long periods, and the use of models can be useful to improve the understanding of such systems. In the present study, the Century model was calibrated and validated to simulate the carbon (C) and nitrogen (N) dynamics in areas of caatinga vegetation before deforestation and during regeneration after abandonment. Calibration data were obtained in field plots in Paraiba state and validation data from plots Rio Grande do Norte state, both areas closely monitored for at least a couple of decades. Two types of deforestation practices were evaluated: clear cutting and cutting with stump removal followed by residue burning. The model files were prepared and calibration parameters were adjusted to represent observed values in the calibration site. Afterwards, the adjusted model was used to simulate the dynamics in the validation site, changing only the site soil and climate characteristics. In areas of preserved native vegetation, the validated C stock values of the woody vegetation biomass (21.0Mgha−1) were similar to the average values observed in the field (20.2Mgha−1). The soil organic carbon stock (SOC) (30Mgha−1) and its C:N ratio (11) were also satisfactorily validated by the Century model, indicating that the model can represent very closely the dynamics in areas under preserved forest vegetation. In areas under regeneration after deforestation, the model also represented well the C accumulation in the biomass of the secondary vegetation and the SOC dynamics for the different firewood harvest practices. The model is very sensitive to the type of deforestation, since the removal of the stumps slows down tree growth during regeneration, therefore it must be well detailed in the site management history during model runs. It is also important to create two different crop files for the herbaceous vegetation within the preserved forest or in the open deforested areas, because they comprise different vegetation types. The model was very sensitive to the KLAI variable, which controls the buildup of leaves during the young phase of the trees. After the necessary adaptations, the Century model simulated adequately C and N cycling in areas of Caatinga vegetation in the semi-arid region of Brazil. The model will now be a useful tool to better understand ecosystem functioning in this region.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.016
      Issue No: Vol. 254 (2017)
       
  • Biological attributes of soil cultivated with corn intercropped with
           Urochloa brizantha in different plant arrangements with and without
           herbicide application
    • Authors: Marco Antonio Moreira de Freitas; Daniel Valadão Silva; Fernanda Rodrigues Guimarães; Patrícia Lopes Leal; Fátima Maria de Souza Moreira; Antonio Alberto da Silva; Matheus de Freitas Souza
      Pages: 35 - 40
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Marco Antonio Moreira de Freitas, Daniel Valadão Silva, Fernanda Rodrigues Guimarães, Patrícia Lopes Leal, Fátima Maria de Souza Moreira, Antonio Alberto da Silva, Matheus de Freitas Souza
      Cultural techniques such as spatial distribution of plants and initial control of the growth rate of forage by applying herbicide sub-doses should be adopted for economic sustainability of intercropping between corn and forage. However, disturbances in the system can affect mycorrhizal colonization, metabolic quotient, microbial respiration, and the number and diversity of arbuscular mycorrhizal fungi (AMF). The objective of this study was to evaluate the effect of nicosulfuron spraying and the seeding density of Urochloa brizantha on soil microbiological attributes. The treatments were arranged in a 2×4 factorial design in randomized blocks. The first factor was nicosulfuron doses (0 and 1/5 of the recommended), and the second factor was the forage seeding densities (0, 2, 4 and 6kg of seeds per hectare). Soil samples were collected 60days after the emergence of corn plants. The respiratory rate, carbon associated with microbial biomass, metabolic quotient, diversity and number of mycorrhizal fungi spores and mycorrhizal colonization were determined in the soil samples. The seeding density of U. brizantha interfered with microbial respiration, metabolic quotient, mycorrhizal colonization and the population of AMFs. A planting density of 8kgha−1 associated with the application of nicosulfuron resulted in a lower metabolic quotient. The increase in forage seeding density linearly reduced corn yield when sub-doses of nicosulfuron were not applied. Management of the spatial distribution of plants and control of initial forage growth by spraying nicosulfuron provide economic and environmental sustainability to the production system.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.10.026
      Issue No: Vol. 254 (2017)
       
  • Cover crop crucifer-legume mixtures provide effective nitrate catch crop
           and nitrogen green manure ecosystem services
    • Authors: Antoine Couëdel; Lionel Alletto; Hélène Tribouillois; Éric Justes
      Pages: 50 - 59
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Antoine Couëdel, Lionel Alletto, Hélène Tribouillois, Éric Justes
      During the fallow period, crucifers grown as catch crops are known to effectively reduce nitrate leaching, while legumes act mainly as green manure by releasing large amounts of mineral nitrogen (N) for the subsequent cash crop once incorporated into the soil. Crucifer-legume cover crop mixtures could be an effective solution for obtaining these two ecosystem services because they combine advantages of both species. However, crucifers might be a poor companion crop due to their high competition for abiotic resources and a potential allelopathic effect on legumes when grown with them. The aim of our study was to assess performances of a wide range of bispecific crucifer-legume mixtures to provide both catch crop and green manure services. A two-year experiment was conducted at two sites (near Toulouse and Orléans, France) where cultivars from eight crucifer species (rape, white mustard, Indian mustard, Ethiopian mustard, turnip, turnip rape, radish and rocket) and nine legume species (Egyptian clover, crimson clover, common vetch, purple vetch, hairy vetch, pea, soya bean, faba bean, and white lupin) were tested in sole-crop and bispecific mixtures (substitutive design of 50%-50% sole crops). We measured cover crop biomass and N acquisition to assess the soil nitrate catch crop service and N green manure service for the subsequent cash crop. In all experiments, compared to bare soil, crucifer-legume mixtures and crucifer sole cover crops provided the same level of nitrate catch crop service by reducing soil mineral N by an average of 59%, while legume sole cover crops reduced it by at least 35%, which is significant. In addition, within 6 months after termination, crucifer-legume mixtures mineralised more N (mean of 22kgNha−1) and thus had a larger N green manure effect for the subsequent cash crop than crucifer sole cover crops (mean of 8kgNha−1). This was due to greater N acquisition and a lower C:N ratio of crucifer-legume mixtures; even though crucifers always had advantage in acquiring N, legumes acquired enough N to provide an effective green manure service. These results were consistent in all of our experiments, which represent a wide range of crucifer-legume cover crops, demonstrating their generality. They also demonstrate the compatibility and complementarity of these species when grown together. In conclusion, combining crucifers and legumes as cover crops is an effective solution for obtaining multi-ecosystem services related to N recycling by providing both nitrate catch crop and N green manure services.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.017
      Issue No: Vol. 254 (2017)
       
  • Rhizosphere soil properties and banana Fusarium wilt suppression
           influenced by combined chemical and organic fertilizations
    • Authors: Jianbo Sun; Liangping Zou; Wenbin Li; Jinghao Yang; Yuguang Wang; Qiyu Xia; Ming Peng
      Pages: 60 - 68
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Jianbo Sun, Liangping Zou, Wenbin Li, Jinghao Yang, Yuguang Wang, Qiyu Xia, Ming Peng
      Combining chemical fertilizer with organic fertilizer is an important management strategy for maintaining soil fertility and disease suppression. Banana is an important cash crop in tropical regions and is severely threatened by Fusarium wilt disease. Little is known about the effects of combined fertilization on rhizosphere soil properties and disease suppression in tropical regions in China. In this study, the effects of combined fertilization on rhizosphere soil properties and the development of banana Fusarium wilt disease were assessed based on key components of soil chemical and biological properties. With chemical fertilization (CF) only, the soil urease, SOC and available nutrients contents were increased continuously, while the soil bacterial diversity, pH, and acid phosphatase activities were initially increased, and then decreased with increasing NPK application rate. Under low NPK application rate (25% CF), the OM addition was more effective in increasing soil bacterial diversity, pH, available nutrients, urease and acid phosphatase activities than NPK fertilization only. However, excessive OM addition had negative effect on soil available P and K content under high NPK application rate (100% CF). The T6 treatment of 50% CF+500 organic matter (OM) had the highest integrated score among the treatments. Path coefficient analysis revealed that soil bacterial diversity plays the most important role in improving soil integrated score. The disease index was significantly and negatively linear correlated with the integrated score (r =−0.92, P< 0.01). These results demonstrate that an appropriate combination of organic and inorganic fertilizer application is effective at improving soil fertility and reduced disease incidence of banana.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.10.010
      Issue No: Vol. 254 (2017)
       
  • Soil nitrous oxide emissions from agricultural soils in Canada: Exploring
           relationships with soil, crop and climatic variables
    • Authors: Philippe Rochette; Chang Liang; David Pelster; Onil Bergeron; Reynald Lemke; Roland Kroebel; Douglas MacDonald; Weikai Yan; Corey Flemming
      Pages: 69 - 81
      Abstract: Publication date: 15 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 254
      Author(s): Philippe Rochette, Chang Liang, David Pelster, Onil Bergeron, Reynald Lemke, Roland Kroebel, Douglas MacDonald, Weikai Yan, Corey Flemming
      National scale emissions of nitrous oxide (N2O) from agricultural soils are often estimated using a unique fertilizer-induced emission factor (EF); thereby neglecting how factors other than nitrogen input could impact emissions. In the present study, we compiled soil N2O flux data collected since 1990 on agricultural soils in Canada, to identify key soil and climate factors, and management practices that explain variations in N2O emissions and in EF. Stepwise regression analysis showed that the growing season precipitation was the most important factor impacting N2O emissions, and that cumulative N2O fluxes and EFs could be predicted using equations (R2 from 0.68 to 0.85) including two to five of the following variables: growing season precipitation, ratio of growing season precipitation to potential evapotranspiration, mean annual air temperature, crop type (annual or perennial), soil pH, texture and organic carbon content. We conclude that N2O EFs could be effectively stratified based on growing season precipitation, soil texture (coarse, medium and fine), type of N (synthetic and organic), and crop type (perennial and annual). We propose EFs that account for the dominant factors that modulate the nitrogen fertilizer-induced emissions and should improve regional and national estimates in Canada. They may also provide useful information for guiding the development of soil N2O emission quantification in other countries.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.10.021
      Issue No: Vol. 254 (2017)
       
  • Effect of grass hedges on runoff loss of soil surface-applied herbicide
           under simulated rainfall in Northern China
    • Authors: Qinghai Wang; Cui Li; Zhuo Pang; Haifeng Wen; Ruilun Zheng; Jie Chen; Xueju Ma; Xiaoe Que
      Pages: 1 - 10
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Qinghai Wang, Cui Li, Zhuo Pang, Haifeng Wen, Ruilun Zheng, Jie Chen, Xueju Ma, Xiaoe Que
      Pesticide loss triggered by runoff is one of the most important sources of non-point pollution. The effects of grass hedges (Melilotus albus and Pennisetum alopecuroides) on atrazine runoff under different rain intensities and slope gradients were evaluated. The plot-scale experiments were carried out on a maize (Zea mays) field on slopes with 15% and 20% gradients using simulated rainfall (rain intensity of 30 and 45mmh−1). Atrazine residues were investigated in runoff water and soil taken from three depths (0–5, 5–10, and 10–15cm) in the middle and base of the slope after runoff events. Total atrazine loss in runoff water ranged from 2.3% to 4.9% of that applied from plots without grass hedges. Grass hedges decreased atrazine loss by 37%-76% and surface runoff by 27%-72%, and Pennisetum showed better efficacy than Melilotus, especially under higher rain intensity. Atrazine loss showed a significant positive linear correlation with surface runoff volume. Grass hedges had a more significant effect on atrazine loss than rain intensity and slope gradient. But they functioned less effectively if used under intense rain or/and steep slope conditions. Atrazine residues remained in the surface 15cm soil were higher for the plots with grass hedges than the control plots. These results suggest that grass hedges not only significantly reduced atrazine loss by reducing the surface runoff, but also reduced the amount of atrazine leaching to deeper soil layer. P. alopecuroides was a suitable grass-hedge species for controlling atrazine losses in northern China and similar regions. Other management practices or control measures should be integrated with grass hedges in strongly sloping cropland in high-rainfall areas to maintain pesticide losses at an acceptable level.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.024
      Issue No: Vol. 253 (2017)
       
  • Mechanism of arsenic uptake, translocation and plant resistance to
           accumulate arsenic in rice grains
    • Authors: Lalith D.B. Suriyagoda; Klaus Dittert; Hans Lambers
      Pages: 23 - 37
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Lalith D.B. Suriyagoda, Klaus Dittert, Hans Lambers
      A global data analysis shows that rice grain arsenic (As) concentrations increase with increasing soil As concentrations until about 60mg As kg−1soil and then decreases. Of the total grain As, 54% is composed of inorganic As. Therefore, when considering the WHO-permissible grain inorganic As concentration, i.e. 0.2mg As kg−1, the permissible grain total As concentrations is 0.37mg total As kg−1grain. Soil total As concentration when grain total As concentration reaches permissible level is 5.5mg As kg−1soil. Therefore, the suitable soil As concentrations for screening rice cultivars in rice agroecosystems for As resistance is 5–60mg As kg−1soil. Rice has traits to reduce uptake and translocation of As to grains. Cultivars with higher root porosity, radial oxygen loss, or formation of iron plaques bind more As to iron plaques, reducing As uptake (i.e. As avoidance). Once taken up, glutathione/glutaredoxin-mediated As reduction, and phytochelatin-dependent complexation and sequestration in vacuoles result in less translocation of As to the grain. Moreover, generation of reactive oxygen species and the production of antioxidant enzymes further reduce As toxicity (i.e. As resistance). These resistance mechanisms in rice agroecosystems are further enhanced when adequate concentrations of silicon and sulfur are present in soils and tissues, and when plants are associated with arbuscular mycorrhizal fungi, particularly under aerobic or intermittent-aerobic soil condition. Therefore, As concentrations in rice ecosystems decrease in the order of: roots > leaves > grains, and in grains: hull > bran polish > brown rice > raw rice> polished rice > cooked rice. Within the grain, As speciation is affected by the location in the grain, forms of As species, the grain-filling stage, geographic origin, ecosystem management and cultivars used. Indica type accumulates more As in their grains than japonica type. Rice grain production, within safe limits of As, requires the consideration of soil As dynamics including soil management, cultivar responses including uptake and translocation, and post-harvest processing techniques.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.017
      Issue No: Vol. 253 (2017)
       
  • Physicochemical characteristics of stored cattle manure affect methane
           emissions by inducing divergence of methanogens that have different
           interactions with bacteria
    • Authors: Chong Liu; Tongjun Guo; Yongxing Chen; Qinghui Meng; Changxiong Zhu; Hongkun Huang
      Pages: 38 - 47
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Chong Liu, Tongjun Guo, Yongxing Chen, Qinghui Meng, Changxiong Zhu, Hongkun Huang
      Greenhouse gas (GHG) emissions from manure management are an environmental concern that hinders the livestock industry. Methane (CH4) is the primary non-CO2 GHG emitted from outdoor manure storage facilities. Understanding the relationship between the microbial community and manure physicochemical characteristics, together with their contributions to CH4 emission during storage are of importance for mitigation and ecological significance. In this study, the archaeal and bacterial communities in manure were investigated using high-throughput sequencing, revealing that manure physicochemical characteristics have a major influence on the distribution and enrichment of methanogenic taxa as well as CH4 emission. Moisture and total phosphorus (TP) were positively correlated with Methanocorpusculum abundance in cow manure with high CH4 emission, while they were negatively correlated with Methanobacterium abundance in heifer manure with low CH4 emission at the species level. Quantitative PCR analysis of transcript abundance of alpha subunit of Methyl coenzyme-M reductase (mcrA) gene in cow manure disclosed relatively strong activity of Methanocorpusculum. sPLS regression and network analyses of microbial taxa revealed that different bacteria–methanogen patterns are associated with CH4 emission. Our data indicates that the manure physicochemical characteristics influence CH4 emissions by altering the divergence of methanogens that differ in transcriptional efficiency of mcrA gene and are correlated with some bacterial taxa, providing insights into the mechanisms of CH4 emission during manure storage.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.020
      Issue No: Vol. 253 (2017)
       
  • Steroid estrogens and estrogenic activity are ubiquitous in dairy farm
           watersheds regardless of effluent management practices
    • Authors: Louis A. Tremblay; Jennifer B. Gadd; Grant L. Northcott
      Pages: 48 - 54
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Louis A. Tremblay, Jennifer B. Gadd, Grant L. Northcott
      Steroid estrogens contamination has been linked to adverse effects on exposed aquatic biota. Steroid estrogens are excreted by all mammals and are found in most agricultural wastes including dairy manure and dairy shed effluent (DSE). Some previous studies have demonstrated elevated levels of free and conjugated estrogenic steroids in DSE and this source has increased as New Zealand has experienced rapid expansion and intensification of dairy farming. This research used an approach incorporating analytical chemistry and bioassays to evaluate the levels of estrogenic activity in environmental samples from representative dairy watersheds with differing DSE management practices: either land-applied or discharged to water. The results demonstrated that estrogenic activity and steroid estrogens were prevalent in the waterways within all the studied dairy watersheds. Estrone was the predominant steroid measured in watershed waters because of its presence in dairy cow wastes and as a degradate of the main dairy cow estrogen, 17α-estradiol. Measurable estrogenic activity (17β-estradiol equivalents, EEq) was found at low levels in 83% of the stream samples (highest 1.44ngL−1 EEq) and 75% of the groundwater samples (≤0.15ngL−1 EEq). While estrogenic activity was generally <1ngL−1, one (of 10) stream with measurable estrone, 17α- and 17ß-estradiol had activity of 1.4ngL−1, a level potentially harmful to aquatic biota. Comparable steroid estrogen concentrations and estrogenic activity were found whether DSE was spray irrigated on farm paddocks or directly discharged into waterways. This suggests that direct access of cattle to streams, the direct input of DSE into waterways and runoff from land application all require more intervention and effective management.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.012
      Issue No: Vol. 253 (2017)
       
  • Contrasting bird communities along production gradients of crops and
           livestock in French farmlands
    • Authors: Camille Dross; Karine Princé; Frédéric Jiguet; Muriel Tichit
      Pages: 55 - 61
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Camille Dross, Karine Princé, Frédéric Jiguet, Muriel Tichit
      Impacts on birds of intensive management practices and of landscape simplification have been widely studied, but there is a lack of knowledge about impacts on birds of landscapes associated with intensive livestock production. The objective of this work was to investigate changes in several bird community descriptors along different production gradients. Production of arable crops and from grazing livestock was computed over French agroecosystems and expressed in terms of edible energy. Using data from the French Breeding Bird Survey along with data from national agricultural statistics, we modeled the relationship between production and five bird community descriptors, namely, community trophic index, community specialization index, and three group-specific species richness indices. Bird communities were shaped by two production gradients. Along a gradient of increasing crop production, we observed a shift from locally species-diverse communities dominated by generalist or grassland specialist species towards species-poor communities dominated by granivorous species specialized in arable habitats (all p-values≤0.002). Second, we observed a shift towards homogenized communities dominated by generalists along a gradient of increasing livestock production (p-values≤0.001). Our research highlights the need to consider crop and livestock separately when investigating their impacts on biodiversity. It also hints towards the need for differentiated strategies to protect farmland birds in crop regions and in livestock regions.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.025
      Issue No: Vol. 253 (2017)
       
  • Critical review of the impacts of grazing intensity on soil organic carbon
           storage and other soil quality indicators in extensively managed
           grasslands
    • Authors: M. Abdalla; A. Hastings; D.R. Chadwick; D.L. Jones; C.D. Evans; M.B. Jones; R.M. Rees; P. Smith
      Pages: 62 - 81
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): M. Abdalla, A. Hastings, D.R. Chadwick, D.L. Jones, C.D. Evans, M.B. Jones, R.M. Rees, P. Smith
      Livestock grazing intensity (GI) is thought to have a major impact on soil organic carbon (SOC) storage and soil quality indicators in grassland agroecosystems. To critically investigate this, we conducted a global review and meta-analysis of 83 studies of extensive grazing, covering 164 sites across different countries and climatic zones. Unlike previous published reviews we normalized the SOC and total nitrogen (TN) data to a 30cm depth to be compatible with IPCC guidelines. We also calculated a normalized GI and divided the data into four main groups depending on the regional climate (dry warm, DW; dry cool, DC; moist warm, MW; moist cool, MC). Our results show that taken across all climatic zones and GIs, grazing (below the carrying capacity of the systems) results in a decrease in SOC storage, although its impact on SOC is climate-dependent. When assessed for different regional climates, all GI levels increased SOC stocks under the MW climate (+7.6%) whilst there were reductions under the MC climate (−19%). Under the DW and DC climates, only the low (+5.8%) and low to medium (+16.1%) grazing intensities, respectively, were associated with increased SOC stocks. High GI significantly increased SOC for C4-dominated grassland compared to C3-dominated grassland and C3-C4 mixed grasslands. It was also associated with significant increases in TN and bulk density but had no effect on soil pH. To protect grassland soils from degradation, we recommend that GI and management practices should be optimized according to climate region and grassland type (C3, C4 or C3-C4 mixed).

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.023
      Issue No: Vol. 253 (2017)
       
  • Can interaction between silicon and plant growth promoting rhizobacteria
           benefit in alleviating abiotic and biotic stresses in crop plants'
    • Authors: Hassan Etesami
      Pages: 98 - 112
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Hassan Etesami
      Increased environmental stresses are among the most limiting factors for agricultural productivity across the world. Reliable, environmentally friendly techniques are needed to sustainably meet growing global food demands. Some plant-microbe interactions can alleviate stress, with the application of plant growth promoting rhizobacteria (PGPRs) that is now widely in use. It has been known that PGPRs enhance plant growth and plant tolerance to biotic and abiotic stresses by different action mechanisms, often more than one mechanism. Application of silicon (Si) can also stimulate plant growth and alleviate an array of biotic and abiotic stresses in plants. In addition, Si is not detrimental to plants and, depending on application method, can be free from pollution even when applied in excess. Here, I compare and contrast the mechanisms, as far as they are known, through which Si and PGPRs can alleviate abiotic and biotic stresses in plants. Both alleviate a similar suite of abiotic and biotic stresses, with a few interesting exceptions, though mechanisms differ. I suggest the combined use of Si and PGPRs can be a powerful and sustainable strategy to enhance plant growth in sub-optimal conditions, and hence experiments assessing the combined use of Si and PGPRs on plants suffering abiotic and biotic stress can be fruitful in the future.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.11.007
      Issue No: Vol. 253 (2017)
       
  • Assessment of site-specific drivers of farmland abandonment in mosaic-type
           landscapes: A case study in Vidzeme, Latvia
    • Authors: Ivo Vinogradovs; Oļģerts Nikodemus; Didzis Elferts; Guntis Brūmelis
      Pages: 113 - 121
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Ivo Vinogradovs, Oļģerts Nikodemus, Didzis Elferts, Guntis Brūmelis
      Farmland abandonment, which causes changes in rural life and farming practices, can be observed throughout Europe. Over the last decades natural afforestation has decreased the area of farmland used for agricultural production, thereby leading to landscape homogenization and polarization. This process is explicitly evident in mosaic type landscapes consisting of highly complex land cover patterns, soil composition and topography. The aim of the study was to determine the site-specific driving forces of farmland abandonment at landscape scale in relation to agro-ecological and geographic factors, in a post-Soviet country in Eastern Europe. An extensive field survey approach with statistical analysis was developed to model landscape change in a case study area in the western part of Vidzeme Uplands, Latvia. The results showed that land quality, proximity to forest edge and distance from farm were strong determinants of farmland abandonment in the mosaic type landscapes and that these parameters can be used to determine probability of occurrence of farmland abandonment. Land quality, a composite indicator, was a robust factor associated with farmland abandonment, in contrast to specific factors like soil texture. The developed model can be employed to assess risk of farmland abandonment in mosaic type landscapes, thus providing valuable information and application as a tool for agricultural policy makers and rural planners.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.016
      Issue No: Vol. 253 (2017)
       
  • Biochar and mill ash improve yields of sugarcane on a sand soil in Florida
    • Authors: Odiney Alvarez-Campos; Timothy A. Lang; Jehangir H. Bhadha; J. Mabry McCray; Barry Glaz; Samira H. Daroub
      Pages: 122 - 130
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Odiney Alvarez-Campos, Timothy A. Lang, Jehangir H. Bhadha, J. Mabry McCray, Barry Glaz, Samira H. Daroub
      The addition of organic residues to sand soils can improve soil properties and sugarcane productivity. However, biochar use can have variable effects on crops, and few studies have evaluated the effect of mill ash applications on sand soils. This study aimed to determine the effect of mill ash, and three biochars on yields of sugarcane grown on sand soils of South Florida near the Everglades Agricultural Area (EAA). Nine treatments and a control were evaluated. Treatments consisted of mill ash (AS) and biochars produced from hardwood yard waste (HY), horse barn shavings (HM), and rice hulls (RH) incorporated at 1% and 2% (by weight) prior to the plant-cane crop of a lysimeter experiment that extended for two crop cycles. A standard practice treatment of mill ash applied at 6% was also included. Results show that mill ash applied at 6% and 2% (AS6 and AS2), and rice hulls biochar applied at 2% (RH2) produced significantly greater biomass and sucrose yields compared with the control in the plant-cane and the first-ratoon crops. Soil silicon concentrations increased with AS and RH in the plant-cane crop, which may have contributed to improved yields. Treatments AS6 and RH2 may have also increased sugarcane yields through improved soil properties. Our results show that mill ash and rice hulls biochar amendments can potentially improve sugarcane yields on sand soils near the EAA.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.11.006
      Issue No: Vol. 253 (2017)
       
  • Farmland heterogeneity benefits bats in agricultural landscapes
    • Authors: Liv Monck-Whipp; Amanda E. Martin; Charles M. Francis; Lenore Fahrig
      Pages: 131 - 139
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Liv Monck-Whipp, Amanda E. Martin, Charles M. Francis, Lenore Fahrig
      Pressure to increase food production poses a challenge for biodiversity conservation in agricultural landscapes. Previous studies suggest that one potential way to enhance biodiversity without taking land out of production is to increase the landscape heterogeneity of farmland by increasing the diversity of crop types in the landscape, and/or the complexity of the spatial pattern of the crop fields (e.g., by decreasing field sizes). Thus we hypothesize that farmland heterogeneity should also increase bat abundance and richness in agricultural landscapes. Here, we use data on bat activity and richness collected using acoustic surveys in rural eastern Ontario, Canada to test the predictions that there should be greater bat activity and greater species richness in agricultural landscapes with higher Shannon diversity of crops and smaller fields, when controlling for the effect of total crop cover. Bat activity increased with farmland heterogeneity, as predicted. Farmland heterogeneity was also positively related to species richness, although the relationship was not statistically supported. Positive effects of farmland heterogeneity on bats will be of interest to farmers and agricultural policy-makers, given the potential economic benefits of pest control by bats.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.11.001
      Issue No: Vol. 253 (2017)
       
  • Plant-pollinator interactions and bee functional diversity are driven by
           agroforests in rice-dominated landscapes
    • Authors: Annika Louise Hass; Bernhard Liese; Kong Luen Heong; Josef Settele; Teja Tscharntke; Catrin Westphal
      Pages: 140 - 147
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Annika Louise Hass, Bernhard Liese, Kong Luen Heong, Josef Settele, Teja Tscharntke, Catrin Westphal
      Wild and domestic bees are essential for the pollination of crops in home gardens, agroforests and vegetable fields of rice smallholders. However, it remains unclear how rice fields and agroforests affect pollinator communities. We investigated the effects of habitat loss and isolation on four different components of bee diversity: abundance, species richness, functional diversity, and plant-pollinator interactions. Flower-visiting bees were recorded in a lowland rice-based production region on the Philippines. We sampled two different land use systems (agroforests and rice fields) and along a gradient of habitat isolation (isolated rice fields and rice fields connected to agroforests). All components of bee diversity were higher in agroforests than in rice fields. Especially above-ground nesting and long-tongued species were adversely affected by rice field habitats and body sizes decreased with isolation from agroforests. For plant-pollinator interactions we found that plants received less diverse pollinator visits in isolated rice fields. In conclusion, agroforests provide important food and nesting resources for bees that translate into taxonomically and functionally diverse pollinator communities as well as stable pollinator visitation networks. These cultivation systems should therefore be maintained or expanded to ensure pollination services and biodiversity conservation. On the contrary, rice fields provide habitat for only few generalist bee species and flower visitation is reduced in isolated rice fields, possibly also leading to impaired pollination of wild plants and crops. Connectivity between bee habitats located in rice production areas is probably disrupted even after a few hundred meters and should therefore be promoted by measures like flower strips in rice fields.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.019
      Issue No: Vol. 253 (2017)
       
  • Indirect interactions between crops and natural vegetation through flower
           visitors: the importance of temporal as well as spatial spillover
    • Authors: Lavhelesani D. Simba; Stefan H. Foord; Elisa Thébault; F.J.Frank van Veen; Grant S. Joseph; Colleen L. Seymour
      Pages: 148 - 156
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Lavhelesani D. Simba, Stefan H. Foord, Elisa Thébault, F.J.Frank van Veen, Grant S. Joseph, Colleen L. Seymour
      As the Anthropocene advances, understanding the complex web of interactions between species has become a central theme in the maintenance of biodiversity, ecosystem functions, and agricultural systems. Plant-flower visitor networks yield insights into how natural vegetation supports crop pollination. Although crops themselves also support pollinators, the importance of spillover of flower-visiting pollinators from natural vegetation into croplands is increasingly appreciated. Natural vegetation not only provides forage and nesting sites, but can also support crop flower visitors when the crop is not flowering. We evaluated indirect effects between mango (the dominant tropical fruit crop globally) and wild plant species in neighbouring vegetation, and the factors determining these indirect effects, by constructing flower visitor networks. We constructed these networks for transects that included mango fields and neighbouring natural vegetation in north-eastern South Africa. Surveys were conducted before, during and after mango flowering, to allow evaluation of the importance of pollinator support when the crop was not in flower. Network analysis showed that potential indirect effects of other plant species on mango increased with flower abundance of those species, although this increase was less marked for species growing in natural vegetation. The cumulative (total, i.e. indirect effects summed) effect of natural vegetation on mango flower visitation was greater both during mango flowering and when it was not flowering. This is likely because of the greater plant diversity in natural systems, and because the combination of these species provided flowers over a protracted period. These positive indirect effects among plants flowering over extended periods of time have to date rarely been considered in crop pollination studies. Given the rapid expansion of high-intensity, high-yield monoculture plantings, such effects warrant further investigation.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.002
      Issue No: Vol. 253 (2017)
       
  • Rotational and continuous grazing does not affect the total net ecosystem
           
    • Authors: Louis Gourlez de la Motte; Ossénatou Mamadou; Yves Beckers; Bernard Bodson; Bernard Heinesch; Marc Aubinet
      Pages: 157 - 165
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Louis Gourlez de la Motte, Ossénatou Mamadou, Yves Beckers, Bernard Bodson, Bernard Heinesch, Marc Aubinet
      Grassland carbon budgets are known to be greatly dependent on management. In particular, grazing is known to directly affect CO2 exchange through consumption by plants, cattle respiration, natural fertilisation through excreta, and soil compaction. This study investigates the impact of two grazing methods on the net ecosystem exchange (NEE) dynamics and carbon balance, by measuring CO2 fluxes using eddy covariance in two adjacent pastures located in southern Belgium during a complete grazing season. Rotational (RG) grazing consists of an alternation of rest periods and short high stock density grazing periods. Continuous grazing (CG) consists of uninterrupted grazing with variable stocking rates. To our knowledge, this is the first study to assess the impact of these grazing methods on total net ecosystem exchange and CO2 exchange dynamics using eddy covariance. The results showed that NEE dynamics were greatly impacted by the grazing method. Following grazing events on the RG parcel, net CO2 uptake on the RG parcel was reduced compared to the CG parcel. During the following rest periods, this phenomenon progressively shifted towards a higher assimilation for the RG treatment. This behaviour was attributed to sharp biomass changes in the RG treatment and therefore sharp changes in plant photosynthetic capacity. We found that differences in gross primary productivity at high radiation were strongly correlated to differences in standing biomass. In terms of carbon budgets, no significant difference was observed between the two treatments, neither in cumulative NEE, or in terms of estimated biomass production. The results of our study suggest that we should not expect major benefits in terms of CO2 uptake from rotational grazing management when compared to continuous grazing management in intensively managed temperate pastures.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.11.011
      Issue No: Vol. 253 (2017)
       
  • Economic, policy, and social trends and challenges of introducing oilseed
           and pulse crops into dryland wheat cropping systems
    • Authors: Tai Maaz; J.D. Wulfhorst; Vicki McCracken; John Kirkegaard; David R. Huggins; Ildiko Roth; Harsimran Kaur; William Pan
      Pages: 177 - 194
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Tai Maaz, J.D. Wulfhorst, Vicki McCracken, John Kirkegaard, David R. Huggins, Ildiko Roth, Harsimran Kaur, William Pan
      The productivity of semi-arid, cereal-based agroecosystems is inherently limited by water and nutrient availability, with water limitations expected to be exacerbated by climate change. While previous studies have identified agronomic, economic, and environmental benefits of rotating oilseed, pulse, and cover crops with cereals for mitigating the effects of increasing temperatures and water shortages, the successful integration of alternative crops into cereal based systems is contingent upon economic, social, and policy conditions. This paper analyses the historical spatial and temporal trends in crop diversification in three distinct cropping regions, including the Canadian prairies, Australian wheat belt, and the inland Pacific Northwest USA (iPNW). The first objective was to identify key sociological, economic, and policy drivers that corresponded with historical crop intensification and diversification in Canada and Australia over the last 50 years. The second objective was to identify key economic, policy, and social constraints that have historically limited intensification and diversification in the iPNW, a cereal-dominated region. In Canada and Australia, public policy played a critical role in the adoption of alternative crops through investments in research and boundary-spanning agencies, as well as extension and grower-led efforts. Policies also provided incentives for market development and risk management strategies. Grower perceptions of risk, the ability to utilize existing resources and knowledge, and access to markets were important social considerations for crop diversification. Given the competitiveness of wheat in the iPNW, the largest opportunities for diversification in the iPNW would be provided by (1) the adoption of a crop rotation approach to the economics that capture relative commodity prices, yield stability, and the effects of alternative crops on subsequent wheat performance, (2) the transition away from coupled crop insurance to income-supported, whole farm risk management, and (3) the establishment of multi-commodity groups that replace single crop commodity commissions in the interest of market-driven crop diversification.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.03.018
      Issue No: Vol. 253 (2017)
       
  • Methods to assess between-system adaptations to climate change: Dryland
           wheat systems in the Pacific Northwest United States
    • Authors: John M. Antle; Hongliang Zhang; Jianhong E. Mu; John Abatzoglou; Claudio Stöckle
      Pages: 195 - 207
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): John M. Antle, Hongliang Zhang, Jianhong E. Mu, John Abatzoglou, Claudio Stöckle
      In this paper we propose to extend methods for agricultural impact assessment to study the adaptations that agricultural producers are likely to consider in response to climate change – i.e., the use of different combinations of crop or livestock species and associated changes in management. Analysis of these kinds of adaptations, referred to here as “between-system adaptations” – requires estimates of the counterfactual productivity and cost of production for prospective systems that are not observable in the locations where they could be used. We propose two methods that we call simulation matching and propensity score matching. We apply and compare the results of these methods in a study of wheat-based systems in the U.S. Pacific Northwest. We find substantial differences between the two methods, but these differences do not appear to be systematic or associated with characteristics of the systems. We conclude that the method used for estimating the productivity of the new system introduces an element of uncertainty into adaptation analysis, in addition to the other data, model and scenario uncertainties. Further research is warranted to evaluate alternative methods for analysis of between-system adaptations and their associated uncertainties.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2017.03.017
      Issue No: Vol. 253 (2017)
       
  • From species distributions to climate change adaptation: Knowledge gaps in
           managing invertebrate pests in broad-acre grain crops
    • Authors: Sarina Macfadyen; Garrick McDonald; Matthew P. Hill
      Pages: 208 - 219
      Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253
      Author(s): Sarina Macfadyen, Garrick McDonald, Matthew P. Hill
      Extensive research has shown that climate change will impact the distribution and outbreak potential of invertebrate pests in broad-acre crops. However, much less attention has been placed on translating these likely changes in pest outbreak frequency into practical management options for growers. Dryland grain production systems are generally predicted to be vulnerable to the effects of climate change. An initial step in understanding changes to outbreak potential of different pests is to describe the spatial distribution of different species and communities. Using a bioclimatic modelling approach, we demonstrate how general patterns of distribution for four major invertebrate pests of Australian dryland grain production systems are likely to be altered by climate change. While such models are useful for predicting the direct impacts of climate change on potential species distributions, they are less useful for assessing pest outbreak frequency from direct or indirect changes. In light of this, we explore different tools that can be used to support adaptive management by farmers to limit the impact of induced pest outbreaks. Primarily, research to increase available information of indirect impacts on the pest species and the communities they interact with, including their natural enemies, is required to extend models of pest outbreak potential. Further, incorporation of pests into global crop models combined with monitoring for existing pests and surveillance for new pests is critical for future pest management decision-making. For natural enemies, generalizations around the impact of climate change and flow on effects for pest control services need to be attempted now. The knowledge of potential management interventions is needed by farmers to support improved management decisions in the short-term, but in some cases will also facilitate adaption to climate change in the long-term.

      PubDate: 2017-11-24T18:02:01Z
      DOI: 10.1016/j.agee.2016.08.029
      Issue No: Vol. 253 (2017)
       
  • Are traditional home gardens in southern Ethiopia heading for
           extinction' Implications for productivity, plant species richness and
           food security
    • Authors: Beyene Teklu Mellisse; Katrien Descheemaeker; Ken E. Giller; Tesfaye Abebe; Gerrie W.J. van de Ven
      Pages: 1 - 13
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Beyene Teklu Mellisse, Katrien Descheemaeker, Ken E. Giller, Tesfaye Abebe, Gerrie W.J. van de Ven
      While home garden systems are acknowledged for their capacity of supporting a very dense population, the productivity of these systems and their contribution to food security and dietary diversity are poorly quantified. Although several articles document the decrease in species richness in home gardens due to processes of modernization, relatively little attention has been given to how the change in diversity impacted productivity. Five predominant home garden systems identified in a previous study were intensively monitored during 12 months within four districts of Sidama and Gedeo zones of southern Ethiopia. Data from 24 farms were collected on plant species, soil characteristics, crop inputs, field sizes and crop yields and livestock production. The productivity of enset for both food and feed was lowest in Enset-coffee home gardens. Barley and khat yielded significantly more per ha in Khat-based systems than in other ones. Maize and coffee productivity did not differ significantly between home garden types. Overall crop productivity was lowest in the traditional Enset-coffee systems (1820kgDMha−1) and highest in the newly evolved Enset-cereal-vegetable systems (3020DMkgha−1). Energy productivity from food crops was higher in Enset-based systems (43GJha−1) than in other systems whereas revenue was lowest in Enset-based systems (719US$ha−1) and highest in newly evolved Khat-based systems (6817US$ha−1). The rate of N application through compost explained 30% of the variability in kocho standing biomass. The rate of N application in inorganic fertilizer explained 43% and 25% of the variability in khat and barley yield respectively. There was no positive effect of plant species richness on total crop and energy productivity except for the revenue in enset-oriented systems. Khat-based and Enset-cereal-vegetable systems were more food secure than the traditional home gardens, and these newly evolved systems also did not lead to a loss in plant species richness. The modification of traditional home garden systems by introducing the high value cash crop khat and annual cereals in response to farmland constraints and market opportunities enabled smallholders to maintain food security and dietary diversity without jeopardizing plant species richness. With population density expected to continually increase in the region, improvement options tailored to the specific systems are required for sustainable development.

      PubDate: 2017-10-14T13:55:41Z
      DOI: 10.1016/j.agee.2017.09.026
      Issue No: Vol. 252 (2017)
       
  • Transport mechanisms for veterinary pharmaceuticals from beef cattle
           feedyards to wetlands: Is aerial deposition a contributing source'
    • Authors: Melissa A. Sandoz; Kimberly J. Wooten; Sheree L. Clendening; Loren L. Hensley; Lucas R. Smith; Philip N. Smith
      Pages: 14 - 21
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Melissa A. Sandoz, Kimberly J. Wooten, Sheree L. Clendening, Loren L. Hensley, Lucas R. Smith, Philip N. Smith
      Veterinary pharmaceuticals from beef cattle feedyards have, with increasing frequency, been identified as contaminants in aquatic systems. Transport of these pharmaceuticals has generally been assumed to be via manure land application, surface runoff, or groundwater percolation. However, veterinary pharmaceuticals in airborne particulate matter downwind of beef cattle feedyards have recently been documented, indicating that aerial transport and deposition are a potential transport mechanism in arid and semi-arid environments. In this study, 35 hydrologically discrete playa wetlands within 15km of beef cattle feedyards were examined for occurrence of six steroid hormones and eight antibiotics. 17α-trenbolone, estrone, estradiol, tetracycline, chlortetracycline, oxytetracycline, tylosin, and monensin were all detected in either water or sediment samples. Concentrations for the majority of analytes were <15ng/g in sediment and <70ng/L in water. Tylosin and monensin were detected at highest concentrations in water, at 3 and 84μg/L, respectively. A correlation between distance from the nearest beef cattle feedyard and concentration of monensin in playa water was observed, similar to correlations observed between pharmaceutical concentrations and distance from feedyard among air samples collected downwind of feedyards. This study suggests that airborne transport and deposition of pharmaceutical-laden particulate matter are a possible contributor to pharmaceutical concentrations in aquatic systems. Aerial deposition of pharmaceutical-laden particulate matter, not typically included in risk assessments, is of yet poorly characterized but may play a significant role in pharmaceutical transport in arid and semi-arid locations and deserves further investigation.
      Graphical abstract image

      PubDate: 2017-10-14T13:55:41Z
      DOI: 10.1016/j.agee.2017.09.016
      Issue No: Vol. 252 (2017)
       
  • Assessing changes in structural vegetation and soil properties following
           riparian restoration
    • Authors: Robin Hale; Paul Reich; Tom Daniel; Philip S. Lake; Timothy R. Cavagnaro
      Pages: 22 - 29
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Robin Hale, Paul Reich, Tom Daniel, Philip S. Lake, Timothy R. Cavagnaro
      Efforts are underway in many areas to restore riparian zones to arrest and/or reverse their degradation and the subsequent loss of the ecosystem services they provide. Despite strong links between edaphic conditions and riparian zone function, limited research has tested how soil properties respond to restoration, especially in an experimental context. With this important knowledge gap in mind, we established a field experiment to asssess structural vegetation and soil responses in the eight years following livestock exclusion and replanting in lowland streams in south-eastern Australia. On three streams, paired restored and control sites were experimentally established and we monitored vegetation (stem density, cover of bare ground and tree canopy, and loadings of organic matter), once beforehand, and then biennually after restoration. Selected soil properties (total carbon, total nitrogen, plant-available phosphorus) were sampled once shortly after restoration, then after another five years. Significant changes in structural vegetation occurred (e.g. decreased bare ground, increased plant stem density, organic matter, and canopy cover). In contrast, those soil properties did not respond. A mega-drought occurred throughout much of the study which was immediately followed by severe flooding. The floods redistributed organic matter at our study sites, with this effect mediated by vegetation structure: the probability of organic matter retention was positively correlated with groundcover and stem density of plants. The timing of flooding was also correlated with increased soil carbon and nitrogen, which could be due to increased productivity in these systems (for the former), or potentially due to increased fertiliser inputs or increased fixation (for the latter). Our study is the first to comprehensively and experimentally test how vegetation, litter layer and surface soil properties respond following riparian restoration, and will help guide the development and implementation of other monitoring programmes.
      Graphical abstract image

      PubDate: 2017-10-14T13:55:41Z
      DOI: 10.1016/j.agee.2017.09.036
      Issue No: Vol. 252 (2017)
       
  • Effectiveness of field isolation distance, tillage practice, cultivar type
           and crop rotations in controlling phoma stem canker on oilseed rape
    • Authors: L. Hossard; V. Souchere; M.H. Jeuffroy
      Pages: 30 - 41
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): L. Hossard, V. Souchere, M.H. Jeuffroy
      Modern agriculture has led to simpler agricultural landscapes that favour the spread of pathogens and increase pressure from pests and diseases. Landscape-dependent interactions between crops and pathogens, including disease related dispersal patterns, and the benefits of reducing pathogen significance call for the design of disease-suppressive landscapes. Model-based assessment is the most efficient method of choosing among management strategies. Based on a case study in France, we ranked the effectiveness of different crop mosaics for control of phoma stem canker on winter oilseed rape (WOSR). Assessed crop mosaics were developed from strategies defined by local stakeholders: (1) isolating target from source fields (all WOSR or only WOSR harbouring RlmX specific resistance), and (2) specifying tillage on WOSR stubble according to cultivar type (with or without RlmX). Model simulations highlighted the effectiveness of WOSR-isolation as compared to RlmX-isolation. Our analyses suggest that tillage (mouldboard ploughing) was the most important factor in explaining the size and genetic structure of the pathogen population (determinant in explaining the breakdown of resistance), and yield loss. While the pathogen population and yield loss decreased with intensive management of non-RlmX-cultivars (85% of WOSR), the same management with RlmX-cultivars modified the genetic structure of the pathogen population. Increasing isolation distances led to reductions in pathogen population and yield loss only in the strategy of WOSR-isolation. Isolating source and target RlmX-cultivar had no effect on the evolution of the population's genetic structure. Although effective in phoma stem canker control, changing tillage can require significant changes for farms. Isolation distance would require extensive information on the landscape, and imply an aggregation of crops that might or might not be possible depending on a farm's spatial organization. This study could lead to the design of a Decision Support System targeting high risk (diseased) WOSR fields to be ploughed or isolated from the following year's cultivation.

      PubDate: 2017-10-14T13:55:41Z
      DOI: 10.1016/j.agee.2017.10.001
      Issue No: Vol. 252 (2017)
       
  • Methane and nitrous oxide emissions from paddy fields in Japan: An
           assessment of controlling factor using an intensive regional data set
    • Authors: Masako Kajiura; Kazunori Minamikawa; Takeshi Tokida; Yasuhito Shirato; Rota Wagai
      Pages: 51 - 60
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Masako Kajiura, Kazunori Minamikawa, Takeshi Tokida, Yasuhito Shirato, Rota Wagai
      Rice paddy fields, producing a major staple food to support growing world populations, represent a major source of greenhouse gases (GHGs) from agricultural ecosystems. The GHG emissions, mainly as CH4 and N2O from paddy ecosystems, are highly sensitive to both environmental and management factors. Yet the identification of specific factors, a fundamental step for GHG inventory and mitigation, is often limited by data availability. Here, we compiled 572 and 174 data on CH4 and N2O emissions, respectively, from paddy fields across Japan, which arguably represents the most intensive GHG data set from paddy fields per region. We hypothesized that statistical analyses of the intensive data set allow the identification of key factors and possible mechanisms that have not been fully appreciated in the previous studies. Important environmental factors newly identified for CH4 emission were soil type and precipitation pattern. The soil emitted CH4 the most was Histosols (172% higher) and the least was Andosols (32% lower) compared to the other soil types. Our analysis also revealed that the region of severe summer rainfall (southwestern Japan) tended to have higher CH4 emission. The most critical management-related factor was straw incorporation and its timing had significant impact as previously reported. Specifically, CH4 emission was 242% and 59% higher by pre-puddling and post-harvest incorporation, respectively. The CH4 response to straw incorporation had relatively large uncertainty, which partly resulted from the variation in straw mass and soil type (esp. Andosols). In addition, the soils having inherently low CH4 emission due presumably to more oxidized conditions had significantly higher response to straw incorporation. Organic amendment increased CH4 by 35%, while water management effect was unclear. We also found that N2O accounted only for 5.5% of total global warming potential from the paddy fields and was mainly emitted in fallow season (84% of annual emission). The amount of nitrogen fertilizer added, the commonly-used factor to estimate N2O emission (e.g., IPCC guideline) showed no significant relationship with the N2O emission in rice growing season, which may be explained by very low level of fertilizer application in Japanese paddy fields (typically<100kgha−1 y−1) compared to other parts of the world. While some of the findings are unique to specific regions (e.g., Andosols), new findings on the factors and potential mechanisms controlling GHG emissions from rice paddy ecosystems would be useful to develop strategies for regional GHG estimate and for modeling biogeochemical cycle in rice paddy ecosystems.

      PubDate: 2017-10-21T01:32:22Z
      DOI: 10.1016/j.agee.2017.09.035
      Issue No: Vol. 252 (2017)
       
  • Alley cropping: Global patterns of species composition and function
    • Authors: Kevin J. Wolz; Evan H. DeLucia
      Pages: 61 - 68
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Kevin J. Wolz, Evan H. DeLucia
      Alley cropping − the intentional integration of trees and crops − is one of the most common agroforestry practices around the world. To better understand its potential to provide economic and ecological benefits over separately cultivated trees and crops, alley cropping research has expanded significantly over the last few decades. While alley cropping is inherently diverse in its composition and function, no comprehensive inventory of its many forms has been performed. We analyzed historical and geo-climatic trends in species composition and function of all alley cropping field experiments in the literature. A total of 1244 publications from 77 countries over the last 35 years were included. Tree diversity was high across all regions, with 410 species utilized from 192 genera. Dominant trees included Populus and Juglans in the temperate zone, Eucalyptus and Populus in the subtropics, and Leucaena and Gliricidia in the tropics. Alley crops were also highly diverse − 276 species within 181 genera − but were dominated by a few annual grains in each region. Despite the diversity in composition across systems, the agricultural functions of both trees and crops were limited. Trees for biomass were utilized in 82% of temperate experiments, while trees for food, fodder, and crop facilitation were more common in the subtropics and tropics. To best orient the growing interest in alley cropping around the world, this inventory was used to identify existing gaps in the literature and inform future opportunities in alley cropping research. Four frontiers in alley cropping research were identified as (1) within-system tree diversity, (2) tree crops for food and fodder production, (3) perennial alley crops, and (4) trees for crop facilitation via shade, nitrogen fixation, and mulch production.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.005
      Issue No: Vol. 252 (2017)
       
  • A re-evaluation of the agronomic effectiveness of the nitrification
           inhibitors DCD and DMPP and the urease inhibitor NBPT
    • Authors: Terry J. Rose; Rachel H. Wood; Michael T. Rose; Lukas Van Zwieten
      Pages: 69 - 73
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Terry J. Rose, Rachel H. Wood, Michael T. Rose, Lukas Van Zwieten
      Increasing evidence is emerging that enhanced efficiency nitrogen (N) fertilisers (EENFs) can lower nitrous oxide (N2O) emissions from soils, but five recently published meta-analyses reported marginal benefits to agronomic efficiency (biomass or grain yields) when assessed against conventional N fertilisers. Closer inspection of the experiments included in these meta-analyses reveals that the vast majority were designed to evaluate N2O emissions, and thus used only one N fertiliser rate, typically the recommended N fertiliser rate for the local crop production system. We suggest that EENFs are unlikely to increase yields beyond conventional N fertilisers when the control fertiliser treatment is applied at the recommended rate for achieving maximum N-limited yield. To demonstrate our perspective, we re-evaluated data from only those studies comparing yield responses to conventional N fertiliser with those of the nitrification inhibitors dicyandiamide (DCD) and 3,4-dimethylepyrazole phosphate (DMPP) and the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) that included a sub-optimal N rate as well as a control ‘recommended’ N rate. While only 11 published studies met these criteria, the available data suggested that EENF products achieve significantly higher yields over conventional N fertilisers at suboptimal N rates, with the greatest yield difference (11%, P<0.05) generated at 50% of the recommended N rate. Due to the additional costs of EENF products per unit N applied, the question asked should not be ‘can EENFs increase yields'’ but rather ‘to what extent can N application rate be reduced by applying EENFs without loss of yield, and is this economically viable'’ To obtain such information, further studies across a range of crops and environments are needed to more accurately derive agronomic response curves for EENFs and simple calculator tools that factor in the cost of a given EENF at a given time can be used to determine economic viability. Finally, holistic assessment should also consider additional benefits of lower N application rates, such as a reduction in the rate of nitrate leaching-induced soil acidification which has associated longer term management costs.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.008
      Issue No: Vol. 252 (2017)
       
  • Agroforestry systems can mitigate the severity of cocoa swollen shoot
           virus disease
    • Authors: Christian Andres; Wilma J. Blaser; Henry K. Dzahini-Obiatey; George A. Ameyaw; Owusu K. Domfeh; Moses A. Awiagah; Andreas Gattinger; Monika Schneider; Samuel K. Offei; Johan Six
      Pages: 83 - 92
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Christian Andres, Wilma J. Blaser, Henry K. Dzahini-Obiatey, George A. Ameyaw, Owusu K. Domfeh, Moses A. Awiagah, Andreas Gattinger, Monika Schneider, Samuel K. Offei, Johan Six
      Currently, the only effective treatment for cocoa (Theobroma cacao L.) infected with the cocoa swollen shoot virus disease (CSSVD) is to cut and replant infected trees. Hence, the development of preventive control measures and strategies to mitigate the severity of the disease are of utmost importance. While past research has mainly focused on resistance breeding, mild strain cross protection and vector control, diversification measures such as agroforestry have received relatively less attention, despite their potential to mitigate CSSVD severity. Therefore, we studied the effects of shade on CSSVD symptom severity, capsid damage and cocoa yield along a gradient of increasing shade tree abundance in smallholder cocoa farms in Ghana. Furthermore, we measured photosynthetic active radiation and assessed soil fertility in order to elaborate on potential causal factors for possible shade effects on CSSVD symptom severity. Both CSSVD symptom severity and cocoa yields followed quadratic curves, and were found to be lowest and highest in plots with 54% and 39% shade, respectively. The simulated optimal shade levels for CSSVD symptom severity and cocoa yield overlapped between 45%–53%, indicating that agroforestry systems with around 50% shade cover may be an optimal coping strategy to balance CSSVD symptom severity versus reduced cocoa yield until diseased cocoa is replaced with more resistant varieties. Furthermore, our results suggest that rather than soil fertility, high-light and possibly also soil moisture stress may have been responsible for the shade effects on CSSVD symptom severity.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.09.031
      Issue No: Vol. 252 (2017)
       
  • Degradation of Tibetan grasslands: Consequences for carbon and nutrient
           cycles
    • Authors: Shibin Liu; Kazem Zamanian; Per-Marten Schleuss; Mohsen Zarebanadkouki; Yakov Kuzyakov
      Pages: 93 - 104
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Shibin Liu, Kazem Zamanian, Per-Marten Schleuss, Mohsen Zarebanadkouki, Yakov Kuzyakov
      The Tibetan Plateau hosts the world’s largest alpine pastoral ecosystems, dominated by the endemic sedges Kobresia pygmaea and Kobresia humilis. Owing to the very harsh environment and also to soil nitrogen (N) and phosphorus (P) limitations, these pastoral ecosystems are very sensitive to disturbances (e.g. anthropogenic activities and climate change) and recover extremely slowly. Overgrazing on the Tibetan Plateau has caused severe degradation of vegetation and soils in the last 30–50years. For the first time, for Kobresia pastures in Tibetan Plateau, we have summarized and generalized the consequences of pasture degradation for soil organic carbon (SOC) and nutrient (N, P) stocks, and evaluated the main biotic and abiotic mechanisms of their loss. Based on 44 literature studies as well as own data, we demonstrated that 42% of SOC stocks were lost, relative to non-degraded pastures. These SOC losses are similar to the decreases in N stocks (-33%), and aboveground (-42%) and belowground (-45%) plant biomass. Although P losses are lower (-17%), its precipitation reduces its availability for plants. These losses are in fact underestimates, since undisturbed natural sites no longer exist on the Tibetan Plateau. The losses are much higher in the upper 10cm and in some areas extend to complete removal of soil cover. This has dramatic repercussions for local livestock, human populations and river pollution. While some rehabilitation projects have shown positive outcomes, the complete recovery of degraded pastures (e.g. soil fertility, ecosystem stability) is infeasible, because of very slow pedogenic processes, slow vegetation restoration, as well as continuously increasing anthropogenic pressure and climate change. Considering the rapid losses of SOC and nutrients, and the very slow recovery potential, Tibetan pastures in some regions may disappear in the next few decades without proper and effective recovery strategies.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.011
      Issue No: Vol. 252 (2017)
       
  • Rangeland vegetation diversity and transition pathways under indigenous
           pastoralist management regimes in southern Ethiopia
    • Authors: Chuan Liao; Patrick E. Clark
      Pages: 105 - 113
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Chuan Liao, Patrick E. Clark
      Woody plant encroachment on the rangelands has been identified as a major threat to subsistence livestock herding globally. Among various determinants, indigenous pastoralist management regime strongly affects rangeland vegetation dynamics at a fine spatial scale. However, mechanisms of how different vegetation functional groups respond to livestock grazing under complex indigenous management regimes are yet to be explored. By integrating plant survey with GPS-tracking of cattle movement, we investigate rangeland vegetation diversity and spatial distribution of grazing intensity in an indigenous pastoralist community in southern Ethiopia, and explore patterns of plant-livestock interaction. The results indicate that vegetation structure and composition are significantly different under three distinct indigenous land use types. Spatial distribution of grazing intensity is heterogeneous under indigenous rangeland management regimes. Both plant diversity and richness are lower given moderate grazing intensity. While herbaceous cover is generally lower at locations with heavier grazing pressure, moderate grazing intensity is associated with the lowest woody cover. The findings imply that maintaining moderate grazing intensity helps to balance pastoralist livelihoods and resource sustainability.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.009
      Issue No: Vol. 252 (2017)
       
  • Initial responses of grass litter tissue chemistry and N:P stoichiometry
           to varied N and P input rates and ratios in Inner Mongolia
    • Authors: Xiao Sun; Yue Shen; Michael J. Schuster; Eric B. Searle; Jihui Chen; Gaowen Yang; Yingjun Zhang
      Pages: 114 - 125
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Xiao Sun, Yue Shen, Michael J. Schuster, Eric B. Searle, Jihui Chen, Gaowen Yang, Yingjun Zhang
      Anthropogenic nitrogen (N) and phosphorus (P) inputs can alter the stoichiometry of senesced plant tissues, a key trait controlling nutrient cycling. However, it is unclear how fertilization rate affects plant litter tissue chemistry under varied N:P supply ratios. In a 2-year study, we investigated the effects of N and P supply rates at three N:P input ratios (4:1, 16:1, and 60:1) on the chemical constitution and N:P stoichiometry of the litter of two grasses: Leymus chinensis and Stipa krylovii. We further evaluated the differential responses of chemical constitution and N:P stoichiometry in leaf and culm litter of L. chinensis. Combined N and P fertilization increased soil acidity and plant-available N, but decreased plant-available P, especially when fertilization occurred at N:P ratio=60:1. Litter N and P concentrations showed positive response to N and P inputs, and N concentration increased with fertilization rate under N:P ratio=4:1, but P concentration decreased under N:P ratio=60:1. Furthermore, we found stronger responses of N and P in L. chinensis and culms than in S. krylovii and leaves. Stoichiometric responses became more positive with increasing N and P fertilization level at each ratio. Nitrogen and P inputs also significantly improved potassium, copper, and sodium concentrations in senesced shoots independent of fertilization rates except for sodium at N:P ratio=16:1, which had weaker responses in L. chinensis and leaves than in S. krylovii and culms. The effects of N and P inputs on other elements were primarily influenced by species and organs, but were also idiosyncratically affected by input levels at each ratio. These results indicate that decreasing evenness of N and P inputs may have increasingly severe non-linear impacts on nutrient cycling and that these impacts will be greater in L. chinensis-dominated ecosystems compared to those dominated by S. krylovii.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.007
      Issue No: Vol. 252 (2017)
       
  • Effects of nitrogen addition on activities of soil nitrogen acquisition
           enzymes:A meta-analysis
    • Authors: Hao Chen; Dejun Li; Jie Zhao; Kongcao Xiao; Kelin Wang
      Pages: 126 - 131
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Hao Chen, Dejun Li, Jie Zhao, Kongcao Xiao, Kelin Wang
      It has been suggested that elevated nitrogen (N) deposition may increase soil N mineralization in N-limited ecosystems, but the underlying mechanisms have been not adequately explored. Soil N-acquisition enzymes play important roles on organic N mineralization. Thus, their responses to N deposition will be crucial for explaining the above phenomenon. Here, we conducted a meta-analysis from 64 studies to synthesize the responses of soil N-acquisition enzyme activities to N addition. Results showed that N addition significantly increased activities of N-acetylglucosaminidase and urease by 5.5% and 11.6%, respectively. However, N addition had negative or negligible effects on activities of protein-depolymerization enzymes, with no response for non-specific protease and leucine aminopeptidase but a significant decrease of 33.0% for glycine aminopeptidase. Because protein comprises more than 60% of the N in plant and microbial cells, and the protein depolymerization is an important rate-limiting step of organic N mineralization, the suppressed protein depolymerization indicates either that the changes to microbial activity may be not a dominant mechanism for the increased N mineralization in N-limited ecosystems with N addition, or that the increased N mineralization may be overvalued in the previous studies.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.09.032
      Issue No: Vol. 252 (2017)
       
  • Can productivity and profitability be enhanced in intensively managed
           cereal systems while reducing the environmental footprint of
           production' Assessing sustainable intensification options in the
           breadbasket of India
    • Authors: Virender Kumar; Hanuman S. Jat; Parbodh C. Sharma; Balwinder-Singh; Mahesh K. Gathala; Ram K. Malik; Baldev R. Kamboj; Arvind K. Yadav; Jagdish K. Ladha; Anitha Raman; D.K. Sharma; Andrew McDonald
      Pages: 132 - 147
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Virender Kumar, Hanuman S. Jat, Parbodh C. Sharma, Balwinder-Singh, Mahesh K. Gathala, Ram K. Malik, Baldev R. Kamboj, Arvind K. Yadav, Jagdish K. Ladha, Anitha Raman, D.K. Sharma, Andrew McDonald
      In the most productive area of the Indo-Gangetic Plains in Northwest India where high yields of rice and wheat are commonplace, a medium-term cropping system trial was conducted in Haryana State. The goal of the study was to identify integrated management options for further improving productivity and profitability while rationalizing resource use and reducing environmental externalities (i.e., “sustainable intensification”, SI) by drawing on the principles of diversification, precision management, and conservation agriculture. Four scenarios were evaluated: Scenario 1 – “business-as-usual” [conventional puddled transplanted rice (PTR) followed by (fb) conventional-till wheat]; Scenario 2 – reduced tillage with opportunistic diversification and precision resource management [PTR fb zero-till (ZT) wheat fb ZT mungbean]; Scenario 3 – ZT for all crops with opportunistic diversification and precision resource management [ZT direct-seeded rice (ZT-DSR) fb ZT wheat fb ZT mungbean]; and Scenario 4 – ZT for all crops with strategic diversification and precision resource management [ZT maize fb ZT wheat fb ZT mungbean]. Results of this five-year study strongly suggest that, compared with business-as-usual practices, SI strategies that incorporate multi-objective yield, economic, and environmental criteria can be more productive when used in these production environments. For Scenarios 2, 3, and 4, system-level increases in productivity (10–17%) and profitability (24–50%) were observed while using less irrigation water (15–71% reduction) and energy (17–47% reduction), leading to 15–30% lower global warming potential (GWP), with the ranges reflecting the implications of specific innovations. Scenario 3, where early wheat sowing was combined with ZT along with no puddling during the rice phase, resulted in a 13% gain in wheat yield compared with Scenario 2. A similar gain in wheat yield was observed in Scenario 4 vis-à-vis Scenario 2. Compared to Scenario 1, wheat yields in Scenarios 3 and 4 were 15–17% higher, whereas, in Scenario 2, yield was either similar in normal years or higher in warmer years. During the rainy (kharif) season, ZT-DSR provided yields similar to or higher than those of PTR in the first three years and lower (11–30%) in Years 4 and 5, a result that provides a note of caution for interpreting technology performance through short-term trials or simply averaging results over several years. The resource use and economic and environmental advantages of DSR were more stable through time, including reductions in irrigation water (22–40%), production cost (11–17%), energy inputs (13–34%), and total GWP (14–32%). The integration of “best practices” in PTR in Scenario 2 resulted in reductions of 24% in irrigation water and 21% in GWP, with a positive impact on yield (0.9t/ha) and profitability compared to conventional PTR, demonstrating the power of simple management changes to generate improved SI outcomes. When ZT maize was used as a diversification option instead of rice in Scenario 4, reductions in resource use jumped to 82–89% for irrigation water and 49–66% for energy inputs, with 13–40% lower GWP, similar or higher rice equivalent yield, and higher profitability (27–73%) in comparison to the rice-based scenarios. Despite these advantages, maize value chains are not robust in this part of India and public procurement is absent. Results do demonstrate that transformative opportunities exist to break the cycle of stagnating yields and inefficient resource use in the most productive cereal-based cropping systems of South Asia. However, these SI entry points need to be placed in the context of the major drivers of change in the region, including market conditions, risks, and declining labor availability, and matching with the needs and interests of different types of farmers.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.006
      Issue No: Vol. 252 (2017)
       
  • Methane and nitrous oxide emissions from conventional and modified rice
           cultivation systems in South India
    • Authors: Aung Zaw Oo; Shigeto Sudo; Kazuyuki Inubushi; Masayoshi Mano; Akinori Yamamoto; Keitsuke Ono; Takeshi Osawa; Sachiko Hayashida; Prabir K. Patra; Yukio Terao; P. Elayakumar; K. Vanitha; C. Umamageswari; P. Jothimani; V. Ravi
      Pages: 148 - 158
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Aung Zaw Oo, Shigeto Sudo, Kazuyuki Inubushi, Masayoshi Mano, Akinori Yamamoto, Keitsuke Ono, Takeshi Osawa, Sachiko Hayashida, Prabir K. Patra, Yukio Terao, P. Elayakumar, K. Vanitha, C. Umamageswari, P. Jothimani, V. Ravi
      Rice (Oryza sativa L.) production is facing major challenges, including scarcity of irrigation water and ongoing climate change. Modifications of the current cropping techniques could increase yield, save water, and mitigate greenhouse gas emission. We investigated the effect of planting methods (young seedlings, wide spacing with alternate wetting and drying irrigation [YW-AWD], old seedlings, narrow spacing with continuous flooding [ON-CF], and in-between the two planting methods [IB-AWD]) and rice varieties on methane (CH4) and (N2O) emissions during two crop seasons. The results show that CH4 emission, averaged over rice varieties, reduced for YW-AWD by 41% and 24%, compared with ON-CF, while the reduction in emission for the IB-AWD method was 48% and 26% in summer (dry) and monsoon (wet) season, respectively. However, an increase in N2O emission was observed for YW-AWD and IB-AWD methods in both seasons. There was no significant difference in CH4 and N2O emissions between the tested varieties. The total water saving under YW-AWD and IB-AWD was 47.5% and 49.3% in summer, and 79.4% and 79.8% in monsoon season, respectively, compared with ON-CF. The grain yields of YW-AWD and IB-AWD were comparable with the yield of ON-CF in both seasons. The CO2-eq emission and yield-scaled CO2-eq emission from YW-AWD and IB-AWD were significantly lower compared with ONCF due to low CH4 emission, while maintaining similar rice yields. This study showed that the YW-AWD and IB-AWD methods are effective in reducing CO2-eq emission and saving irrigation water, while maintaining the rice yield.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.014
      Issue No: Vol. 252 (2017)
       
  • Modelling daily to seasonal carbon fluxes and annual net ecosystem carbon
           balance of cereal grain-cropland using DailyDayCent: A model data
           comparison
    • Authors: Nimai Senapati; Abad Chabbi; Pete Smith
      Pages: 159 - 177
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Nimai Senapati, Abad Chabbi, Pete Smith
      Croplands are important not only for food and fibre, but also for their global climate change mitigation and carbon (C) sequestration potentials. Measurements and modelling of daily C fluxes and annual C balance, which are needed for optimizing such global potentials in croplands, are difficult since many measurements, and the correct simulation of different ecosystem processes are needed. In the present study, a biogeochemical ecosystem model (DailyDayCent) was applied to simulate daily to seasonal C fluxes, as well as annual net ecosystem carbon balance (NECB), in a cereal grain-cropland. The model was tested using eddy-flux data and other associated C flux measurements lasting for three years over a full cereal crop-rotation (corn-wheat-barley) from a long-term experiment (SOERE–ACBB; http://www.soere-acbb.com) in France. DailyDayCent simulated seasonal crop growth, regrowth of volunteers and cumulative net primary production (NPP) at harvest successfully. Fairly consistent agreement was obtained between measured and modelled daily NPP over the full crop rotation, with model efficiency (EF) of 0.59. The model underestimated heterotrophic respiration (Rh ) on daily, seasonal and annual time scales by 43–53%. Although a reasonable model fit was found for daily NEE over the entire experimental period (EF ∼0.47), the model overestimated cumulative annual net C uptake (NEE) by 28 times. DailyDayCent simulated net C harvest efficiently, and the leaching loss of C reasonably well. Both the modelled and measured mean annual NECB indicate that present cereal grain-cropland is a net C source and the cropland is losing C at a mean annual rate of 64.0 (modelled) to 349.4gCm−2 yr−1 (measured), thus the model overestimated mean annual NECB (or underestimated mean annual net C loss) in the present cropland by 82%. We conclude that overestimation of cumulative NEE on seasonal and annual time scales is the most likely reason for overestimation of NECB, and underestimation of Rh was the main driver for overestimation of cumulative seasonal and annual NEE. The model would benefit from further testing, particularly against direct measurements of Rh , and subsequent calibration, parameter estimation and model development for improving its ability to simulate Rh on daily to seasonal and annul time scales, cumulative seasonal and annual NEE, and net C balance, especially in cereal grain-croplands in the study region.
      Graphical abstract image

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.003
      Issue No: Vol. 252 (2017)
       
  • Effects of long-term cultivation on phosphorus (P) in five low-input,
           subtropical Australian soils
    • Authors: Peter M. Kopittke; Ram C. Dalal; Peng Wang; Neal W. Menzies
      Pages: 191 - 199
      Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252
      Author(s): Peter M. Kopittke, Ram C. Dalal, Peng Wang, Neal W. Menzies
      Despite the importance of P for cropping, there remains uncertainty regarding the effects of long-term cropping on P behaviour in soils. Using five soils (Billa Billa, Cecilvale, Riverview, Thallon, and Waco) from subtropical Australia cropped for ≤70y with low rates of P-fertilizer inputs, changes in soil P (organic, inorganic, and total) were assessed and related to P removal in wheat grain. For four of the five soils, concentrations of organic P decreased significantly with increasing period of cropping, decreasing between 20 and 36%. In contrast, concentrations of inorganic P generally remained relatively constant. Despite the decrease in organic P, the C/P ratio remained relatively constant in all five soils (average of 99), indicating that organic P is protected within the soil organic matter in a manner similar to the organic C. Furthermore, although increasing period of cropping decreased soil organic P concentrations, grain P concentrations decreased significantly only for Billa Billa and Thallon. Finally, although the rate of P removal in grain was low (1.6 to 9.3kgha−1 y−1), the rate of removal exceeded inputs from P-containing fertilizers. Thus, there is a need to consider the long-term P-fertilization to ensure adequate P nutrition of the crops. This study provides important information regarding changes in P within long-term cropping systems and will assist in their sustainable management.

      PubDate: 2017-11-12T01:03:06Z
      DOI: 10.1016/j.agee.2017.10.018
      Issue No: Vol. 252 (2017)
       
  • Inside Front Cover - Editorial Board Page
    • Abstract: Publication date: 1 February 2018
      Source:Agriculture, Ecosystems & Environment, Volume 253


      PubDate: 2017-11-24T18:02:01Z
       
  • Inside Front Cover - Editorial Board Page
    • Abstract: Publication date: 15 January 2018
      Source:Agriculture, Ecosystems & Environment, Volume 252


      PubDate: 2017-11-12T01:03:06Z
       
 
 
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