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Showing 1 - 200 of 3042 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 19, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 81, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 23, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 326, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 203, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 22, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 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: 3)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 124, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 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: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 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 Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 40, 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: 44, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12)
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: 20, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
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: 34, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 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: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, 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 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: 21, 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: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 58)
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 Research     Full-text available via subscription   (Followers: 339, 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: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 29, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 15)
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: 43, 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: 311, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 398, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 30, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 38, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 50, 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: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 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: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 46, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 46, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 45, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 15, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 30, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 24, 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: 44, 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: 182, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 54, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 23, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 33, 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: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 52, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 4)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 161, 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: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 153, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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Journal Cover Agriculture, Ecosystems & Environment
  [SJR: 1.879]   [H-I: 120]   [50 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0167-8809 - ISSN (Online) 1873-2305
   Published by Elsevier Homepage  [3042 journals]
  • DMPP is ineffective at mitigating N2O emissions from sheep urine patches
           in a UK grassland under summer conditions
    • Authors: Karina A. Marsden; Davey L. Jones; David R. Chadwick
      Pages: 1 - 11
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Karina A. Marsden, Davey L. Jones, David R. Chadwick
      Nitrification inhibitors are a potential technology to mitigate N2O emissions from the urine patches of grazing animals. At present, there is limited information regarding the efficacy of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) in reducing N2O emissions from ruminant urine patches, as opposed to the well-studied nitrification inhibitor, dicyandiamide. In practical terms, urine patches would be deposited to soil at various times following the application of a nitrification inhibitor to soil. We hypothesised that the effectiveness of DMPP in reducing cumulative N2O emissions would decrease the longer the time since DMPP application. This study utilised an automated closed chamber technique, to monitor fluxes of N2O from sheep urine patches (725kg Nha−1; 150ml; 300cm2) deposited to a Eutric Cambisol, where DMPP was applied (1kgha−1) on the same day, 2 weeks before and 4 weeks before urine application. Fluxes were monitored continuously from 4 weeks before, to 9 weeks after, urine application. DMPP was found to be ineffective at reducing cumulative N2O emissions and 9-week urine-N2O emission factors when applied at the same time as the sheep urine, although a low number of replicates were used in this study. Some effect of DMPP in delaying the accumulation of soil NO3 − was observed, with effects being greater the shorter the time since DMPP application. The temporal dynamics of N2O fluxes were also altered where DMPP was applied on the same day as the urine. Heterogeneity in soil conditions were deemed responsible for the large spatial variability of N2O emissions observed in this study. The use of Rhizon samplers were useful for detecting spatial variability within the soil solution directly beneath the urine patches (within the flux chambers), which may not have been detected within duplicate urine patches (outside the chambers), where soil sampling was conducted. Further work is required to determine the loading rate and duration of efficacy of DMPP to reduce emissions from urine patches under temperate summer conditions.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.017
      Issue No: Vol. 246 (2017)
  • Relative effects of local management and landscape heterogeneity on weed
           richness, density, biomass and seed rain at the country-wide level, Great
    • Authors: Audrey Alignier; Sandrine Petit; David A. Bohan
      Pages: 12 - 20
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Audrey Alignier, Sandrine Petit, David A. Bohan
      Weed management is a critical issue as it is faced with a daunting set of challenges linked to crop productivity and farmland biodiversity. Developing new strategies for weed management requires a clear understanding of the relative role of local management and landscape heterogeneity on weeds. Yet few studies have investigated the combined effect of these factors on a variety of weed metrics that reconcile agronomical and ecological aims. Here, we analyzed the relative role of local management intensity and landscape heterogeneity according to the distance to field margin on four weed metrics (species richness, density, biomass and seed rain) and community composition in 257 fields (beet, maize, spring and winter rape fields) across Great Britain. Generalized mixed effect models followed by a model averaging procedure were applied on weed metrics and permutational multivariate analyses of variance were applied on weed species composition. Our analysis confirmed the overriding role of the distance to field margin on weeds. Although weed density and seed rain negatively responded to local management intensity, they did not respond in the same way to landscape configurational heterogeneity, namely the field size. We found interactions between management intensity and landscape heterogeneity but only in relation to weed biomass in beet and spring rape fields and to seed rain in beet fields. The relative importance of local management intensity and landscape heterogeneity varied depending on the distance to field margin, which can be attributed to spatial heterogeneity in management practices. We recommend that not only species richness but also a wide range of metrics should be considered in weed studies as they did not responded in the same way to local and landscape factors. We conclude that weed management strategies should be thought by integrating a multi-level approach as the combined effects of local management and landscape heterogeneity are likely to both reduce weed infestation whilst enhancing biodiversity.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.025
      Issue No: Vol. 246 (2017)
  • Variation in specific root length among 23 wheat genotypes affects leaf
           δ13C and yield
    • Authors: Paola E. Corneo; Claudia Keitel; Michael A. Kertesz; Feike A. Dijkstra
      Pages: 21 - 29
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Paola E. Corneo, Claudia Keitel, Michael A. Kertesz, Feike A. Dijkstra
      Identifying root traits that are associated with efficient nutrient and water utilization is crucial for improving plant functioning and productivity. In the case of wheat genotypes, such root traits could be used by plant breeders to improve grain yield and quality. In this study 23 wheat genotypes (Triticum spp.) belonging to different breeding groups were planted in a randomized block design field experiment in NSW, Australia and fertilized with 100 (LN) and 234kgNha−1 (HN). Root traits were measured at stem elongation, and aboveground plant material was collected at stem elongation, grain filling and plant maturity. Differences in specific root length (SRL, the ratio of root length to dry mass) among genotypes confirmed their genotypic variability. SRL in the topsoil at stem elongation was a good predictor of leaf δ13C (a proxy of leaf-scale water use efficiency, WUEi) both at grain filling and at plant maturity, and of grain yield in both LN and HN treatments. Notably, genotypes with higher SRL (longer and thinner roots) had a higher leaf δ13C (i.e. higher WUEi) and N concentrations and were associated with lower grain yield. High N rates increased leaf δ13C and N concentrations without overall increasing grain yield. Genotypes with higher SRL were more responsive to higher rates of fertilization producing leaves with higher N and grain with higher protein concentrations. Therefore, SRL is a key root trait affecting grain yield through control on soil water uptake, and affecting grain quality through control on soil N uptake when N availability is high. We suggest that SRL should be considered by plant breeding schemes as a target trait to modify grain yield and quality.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.012
      Issue No: Vol. 246 (2017)
  • Changes in microbial communities and respiration following the
           revegetation of eroded soil
    • Authors: Haibing Xiao; Zhongwu Li; Yuting Dong; Xiaofeng Chang; Lei Deng; Jinquan Huang; Xiaodong Nie; Chun Liu; Lin Liu; Danyang Wang; Qiming Liu; Yanru Zhang
      Pages: 30 - 37
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Haibing Xiao, Zhongwu Li, Yuting Dong, Xiaofeng Chang, Lei Deng, Jinquan Huang, Xiaodong Nie, Chun Liu, Lin Liu, Danyang Wang, Qiming Liu, Yanru Zhang
      It is necessary to assess the responses of microbial communities and respiration to the revegetation of eroded soils for understanding the dynamics of soil carbon (C) pools and fluxes. In this study, three typical abandoned croplands (CL1, CL2 and CL3) and three secondary grasslands planted with Coronilla varia (GL1, GL2 and GL3) on the Loess Plateau of China were selected for sampling, and quantitative polymerase chain reaction (qPCR) and high-throughput sequencing were applied to intuitively discern differences in the soil bacteria and fungi. Our results showed that bacterial abundance in the abandoned croplands was 57 times higher than that of the secondary grasslands (P <0.05), but no obvious changes (P >0.05) in fungal abundance and microbial diversity were observed after 31 years of revegetation. We observed positive responses in Actinobacteria, Firmicutes, Zygomycota and Ciliophora and negative responses in Bacteroidetes and Planctomycetes to revegetation. In addition, the maximum soil microbial respiration was observed in the GL3 site (20.86±0.69mgCO2-Ckg−1 soild−1) followed by the GL1 site (19.97±0.65mgCO2-Ckg−1 soild−1), so revegetation significantly improved (P< 0.05) soil microbial respiration. Multiple stepwise regression analysis showed that dissolved organic carbon (DOC) explained up to 68.5% of the variation in soil microbial respiration, which indicated that the effects of changes in microbial properties in response to revegetation on soil microbial respiration were likely to be smaller than the potential effects of changes in the quality of organic matter. Labile organic matter is the primary rate-limiting factor for soil microbial respiration.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.026
      Issue No: Vol. 246 (2017)
  • Whether conversion of mangrove forest to rice cropland is environmentally
           and economically viable?
    • Authors: Rita Chauhan; Arindam Datta; AL. Ramanathan; Tapan Kumar Adhya
      Pages: 38 - 47
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Rita Chauhan, Arindam Datta, AL. Ramanathan, Tapan Kumar Adhya
      The diverse habitat of the mangrove ecosystems all over the globe are under continuous threat of conversion for immediate and/or short-term economic benefits. Nonetheless, the emission of climatically relevant greenhouse gases increases with the disturbance of the mangrove sediment −this might undermine the credible reservoir of carbon within the sediment. This article attempts to estimate the environmental (carbon emission) and economic consequences of converting mangrove to cropland (especially rice paddy) based on field-scale study at three different sites (Khola, Gupti and Damra) within the Bhitarkanika mangrove for two consecutive years. The study suggests that the cumulative methane (CH4) emission was significantly higher from the rice paddy (211.3kgha−1) compared to the mangrove sediment (50.8kgha−1), while the average nitrous oxide (N2O) emission was significantly higher from the later (2.1kgha−1). Multivariate statistical analysis suggests that the land use was the prime controlling factor for variation in CH4 and N2O emission. Total carbon equivalent emission (CEETOT) from the rice paddy was significantly higher than mangrove during the study period. The study suggests that the economic value of the mangrove ecosystem was several folds higher than that of the rice paddy. The CEETOT of the Bhitarkanika mangrove has increased approximately 212Gg over last few decades due to the conversion of the mangrove area to the rice paddy. Such studies are imperative in developing effective regional climate change adaptation strategies. The study advocates urgent need to educate and aware people about the benefits of the mangrove compared to the cropland.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.010
      Issue No: Vol. 246 (2017)
  • Evaluation of an unpalatable species (Anthemis arvensis L.) as an
           alternative cover crop in olive groves under high grazing pressure by
    • Authors: Antonio J. Carpio; María-Auxiliadora Soriano; José Guerrero-Casado; Laura M. Prada; Francisco S . Tortosa; Ángel Lora; José A. Gómez
      Pages: 48 - 54
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Antonio J. Carpio, María-Auxiliadora Soriano, José Guerrero-Casado, Laura M. Prada, Francisco S . Tortosa, Ángel Lora, José A. Gómez
      Sustainability is a key attribute for the future of the olive grove. Cover crops can be considered as an effective tool to achieve sustainability of olive orchards to reduce soil erosion, improve soil fertility and increase biodiversity. However, wild herbivores may forage on cover crops when natural food resources are scarce. In this study we assessed the impact of European rabbit grazing on the implantation of herbaceous cover crops of two native plant species, one palatable (Bromus rubens L.) and the other unpalatable (Anthemis arvensis L.) in two olive orchards with very scarce vegetation cover in Andalusia, Southern Spain. Eight rabbit exclusion plots, close to eight other unfenced plots, were planted where the aboveground biomass, height and the ground covered by each species were measured. The results showed that the biomass, height and the ground cover by B. rubens were higher in the rabbit exclusion areas (ground cover: 36.5±3.3%; height: 30.3±3.9cm, averaged over the entire measuring period; and biomass: 158±36g/m2, in April) than in unfenced areas (ground cover: 1.9±0.2%; height: 5.6±0.7cm; biomass: ≅0), while A. arvensis showed no difference in biomass, height or ground cover between the two treatments (ground cover: 11.3±6.3%; height: 12.2±7.9cm, averaged over the entire measuring period; and biomass: 49.5±10g/m2, in April). The results further showed that the damage by rabbits was caused from the early stages of development of B. rubens, which avoid its growth; notwithstanding the plant biomass consumption was minimal, the damage caused was critical. These findings suggest that unpalatable species such as A. arvensis could be a suitable tool for establishing herbaceous cover crops in olive groves at high rabbit densities, where other palatable species (e.g., B. rubens) are strongly consumed, thus contributing to soil conservation and improvement in olive groves with soils already degraded by erosion.
      Graphical abstract image

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.028
      Issue No: Vol. 246 (2017)
  • Nitrous oxide emissions from sugarcane fields in the Brazilian Cerrado
    • Authors: Jéssica Fonseca da Silva; Arminda Moreira de Carvalho; Thomaz A. Rein; Thais Rodrigues Coser; Walter Quadros Ribeiro; Douglas Lino Vieira; David A. Coomes
      Pages: 55 - 65
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Jéssica Fonseca da Silva, Arminda Moreira de Carvalho, Thomaz A. Rein, Thais Rodrigues Coser, Walter Quadros Ribeiro, Douglas Lino Vieira, David A. Coomes
      Brazil meets about 16% of its energy needs with bioethanol and other sugarcane products and leads the world in biofuel energy production. However, there are concerns over the environmental credentials of the sugarcane given the high emissions of nitrous oxide (N2O) − a potent greenhouse gas − associated with its production. We quantify N2O fluxes from a sugarcane experiment in the Brazilian Cerrado over an entire year, comparing the magnitude of response to different fertilizer treatments: mineral nitrogen (N), a liquid residue from bioethanol distillation known as vinasse (V) and a combination of both (NV), on irrigated and nonirrigated plots. We find that soil N2O fluxes in plots subjected to the NV treatment are, on average, at least three times higher than those in the other treatments, resulting in four times the emissions intensity per yield than when mineral N or vinasse were applied alone. We also find that irrigation has a positive effect on N2O emissions in the first two weeks after treatment addition and on annual sugarcane yield. Emission factors, defined as net N emissions as N2O as a percentage of the total mineral N added, vary from 0.05 to 4.6% according to treatment. Sugarcane production in the Cerrado is a significant source of N2O, due to the synergistic effect of mineral N fertilizer and vinasse. Using vinasse as the main fertilizer, or applying N and vinasse at widely spaced intervals are effective strategies for climate change mitigation, plant nutrition, waste management and cost-efficient production.
      Graphical abstract image

      PubDate: 2017-06-07T07:26:48Z
      DOI: 10.1016/j.agee.2017.05.019
      Issue No: Vol. 246 (2017)
  • Soil ecological responses to pest management in golf turf vary with
           management intensity, pesticide identity, and application program
    • Authors: Huijie Gan; Kyle Wickings
      Pages: 66 - 77
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Huijie Gan, Kyle Wickings
      While the unintended effects of pesticide applications in agroecosystems have received much attention, the consequence of different pest management strategies for beneficial soil biota in managed grass ecosystems remains poorly documented. In this study, we investigated the responses of major soil biological traits to both the short- and long-term effects of pesticide inputs in golf turfgrass. Overall, golf course fairways receiving regular, high-rate pesticide inputs exhibited suppression in soil biological traits involved in litter decomposition/nutrient mineralization (decomposer arthropod abundance and acid phosphatase activity), and plant nutrient uptake/plant protection (mycorrhizal fungi). In contrast, most beneficial soil biota appeared to tolerate a low level of pesticide input. In a short-term manipulative experiment we observed that monthly applications of chlorothalonil and a single application of imidacloprid, both at a medium label rate, consistently suppressed decomposer microarthropods over a 4-month period. The imidacloprid application also reduced the total infection of mycorrhizae and dark septate endophytes in roots. These results suggest that the use of pesticides as a whole does not always result in negative impacts on soil biota, but rather that the pesticide effects vary among functional groups of soil biota and are contingent upon long-term patterns of pesticide input intensity, and short-term differences in active ingredient and application program (application rate and frequency). These findings highlight opportunities for optimizing management practices to achieve pest management goals without compromising soil ecosystem services.

      PubDate: 2017-06-07T07:26:48Z
      DOI: 10.1016/j.agee.2017.05.014
      Issue No: Vol. 246 (2017)
  • A comparison of policies to reduce the methane emission intensity of
           smallholder dairy production in India
    • Authors: L. York; C. Heffernan; C. Rymer
      Pages: 78 - 85
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): L. York, C. Heffernan, C. Rymer
      Within the dairy sector, the effects of climate change are particularly diverse as cows are affected by, and a significant contributor to climate change. With a burgeoning body of work indicating the importance of livestock’s contribution to climate change (via Greenhouse Gas (GHG) emissions), the dairy sector will increasingly be targeted for emission reduction. Yet, gaps in knowledge remain as to the effectiveness of interventions in achieving emission reductions. The investigation examines two high-profile Indian policies to evaluate their effectiveness in reducing the methane emission intensity of milk production in Odisha, India. Selected policies included the installation of smallscale anaerobic digesters and the control of Foot and Mouth Disease (FMD). The interventions were evaluated at the cow level informed by data collected from 115 smallholder dairy producers in Puri (n=31) and Khurda (n=84) districts in Odisha, India. The installation of an anaerobic digester was found to increase methane emission intensity by 4.41–5.01%. Control of FMD reduced methane emission intensity by 3.68–12.95% depending on the infection scenario considered. The findings highlight the importance of contextually relevant and multi-sectoral approaches to mitigation as the increase in methane emission intensity following anaerobic digester installation represents movement of emissions from the energy sector into the dairy sector where mitigation is inherently more complex. Thus, the long-term usefulness of anaerobic digester installation as a mitigation strategy is limited.

      PubDate: 2017-06-07T07:26:48Z
      DOI: 10.1016/j.agee.2017.05.032
      Issue No: Vol. 246 (2017)
  • Selection of aluminum tolerant cereal genotypes strongly influences the
           arbuscular mycorrhizal fungal communities in an acidic Andosol
    • Authors: P. Aguilera; C. Marín; F. Oehl; R. Godoy; F. Borie; P. Cornejo
      Pages: 86 - 93
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): P. Aguilera, C. Marín, F. Oehl, R. Godoy, F. Borie, P. Cornejo
      In Chile, cereals cultivation is mainly in volcanic soils with pH values typically between 4.5–5.5 and high levels of exchangeable aluminum (Al) and low P availability. In this context, arbuscular mycorrhizal fungi (AMF) provide or enhance protection against this environmental stress. The aim of this study was to investigate the impact of the breeding process of Al-tolerant cereal plants on AMF community structure and diversity associated to cereals species. This breeding program has been developed since 1980 in our country and consists of obtaining cereal plants that can tolerate stress by Al. For this, we contrast cereals species and genotypes in which Al-stress has been included or not in this breeding program. Rhizosphere soils from Al-tolerant cereals recently developed (Avena sativa, Hordeum vulgare, Triticum durum, x. Triticosecale Wittmack, Secale cereale and T. aestivum) were collected from field plots in South-Central Chile. In addition, two cereals with recognized Al-tolerance (Crac wheat cultivar and rye) were also analyzed. AMF identification and taxonomy was performed based on spore morphological analyses. Colonization and glomalin related soil protein (GRSP) was also evaluated. In general, up to 80% of root colonization in all cereal was found. Extraradical mycelium reached levels close to 3mg−1 of soil in the rhizosphere of S. cereale, A. sativa and H. vulgare selected under Al stress. While, GRSP values were statistically similar among selected or not selected genotypes under Al stress, this trend was not observed in H. vulgare, where a difference of 20μg GRSP g−1 of soil was found. Moreover, large differences in AMF spore densities were observed, being 340 spores in 100g soil the lowest and 1900 the highest one, in non Al tolerant H. vulgare and Al tolerant x. Triticosecale Wittmack, respectively. From a total of 10,000 AM fungal spores, 21 AMF species were identified, belonging to three classes, six orders, and eight families. The alpha diversity was higher in Al tolerant T. durum and almost similar to T. aestivum. Evenness index was significantly higher in Al tolerant H. vulgare. As conclusion, the use of target AMF species and cereals obtained under Al stress could be determinant factors for the appropriate AMF community establishment, potential inoculation assays and agricultural practices, especially oriented to soils with high Al levels.

      PubDate: 2017-06-07T07:26:48Z
      DOI: 10.1016/j.agee.2017.05.031
      Issue No: Vol. 246 (2017)
  • Effects of local climate, landscape structure and habitat quality on
           leafhopper assemblages of acidic grasslands
    • Authors: Felix Helbing; Thomas Fartmann; Franz Löffler; Dominik Poniatowski
      Pages: 94 - 101
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Felix Helbing, Thomas Fartmann, Franz Löffler, Dominik Poniatowski
      Grassland biodiversity is severely threatened by recent land-use change. Agricultural intensification on the one hand, and cessation of traditional land use on the other, have caused habitat loss, fragmentation and often a deterioration in habitat quality of the remaining habitat fragments. However, knowledge about the different environmental effects on species richness is still limited, in particular for under-sampled groups like leafhoppers (Auchenorrhyncha). Our study therefore aims to analyse the impact of local climate, landscape structure and habitat quality on leafhopper assemblages. Several environmental factors were assessed and species richness of leafhoppers was sampled on 30 acidic grassland patches in Central Germany. We used generalised linear models (GLM) to determine the variables that influence species richness. Both landscape structure and habitat quality had a strong influence on the number of leafhopper species. At the landscape scale, a high diversity of open land cover types positively affected species richness. Furthermore, species richness increased with decreasing cover of arable land in the surroundings of a habitat fragment. The best predictor at the habitat scale was the structural diversity, which had a positive impact on the numbers of leafhoppers. Local climatic conditions and patch area played a minor role and had an effect only on threatened species. We recommend establishing a great variety of different structural types within a patch in order to promote species-rich leafhopper assemblages. In addition, conservationists should focus their efforts on the maintenance of different types of grasslands in the surroundings of habitat fragments.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.024
      Issue No: Vol. 246 (2017)
  • Flower handling behavior and abundance determine the relative contribution
           of pollinators to seed set in apple orchards
    • Authors: L. Russo; M.G. Park; E.J. Blitzer; B.N. Danforth
      Pages: 102 - 108
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): L. Russo, M.G. Park, E.J. Blitzer, B.N. Danforth
      A growing body of evidence suggests that wild bees play an important role in agricultural pollination. It is very difficult, however, to accurately quantify the contribution of wild bees relative to honeybees in most crop systems. We quantified the relative contribution of honeybees and wild bees to the pollination of an economically important, insect-pollinated crop (apple). We use an empirical dataset to identify which of three functional traits (body size, pollen load purity, and flower handling behavior) contribute significantly to seed set. We find that flower handling behavior and abundance were the only functional traits that significantly predict seed set. When we take into account flower handling behavior and abundance, wild bees contributed significantly more to seed set than honeybees in the apple orchards we surveyed. Our findings suggest that land managers may benefit from focusing on supporting communities of wild bees, rather than investing in honeybee hive rental.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.033
      Issue No: Vol. 246 (2017)
  • Landscape effects on pollinator communities and pollination services in
           small-holder agroecosystems
    • Authors: Yi Zou; Felix J.J.A. Bianchi; Frank Jauker; Haijun Xiao; Junhui Chen; James Cresswell; Shudong Luo; Jikun Huang; Xiangzheng Deng; Lingling Hou; Wopke van der Werf
      Pages: 109 - 116
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Yi Zou, Felix J.J.A. Bianchi, Frank Jauker, Haijun Xiao, Junhui Chen, James Cresswell, Shudong Luo, Jikun Huang, Xiangzheng Deng, Lingling Hou, Wopke van der Werf
      Pollination by insects is key for the productivity of many fruit and non-graminous seed crops, but little is known about the response of pollinators to landscapes dominated by small-holder agriculture. Here we assess the relationships between landscape context, pollinator communities (density and diversity) and pollination of oilseed rape in 18 landscapes with proportions of small-holder farming ranging from 10% to 70% in southern China. To quantify the contribution of pollinators to oilseed rape yield, we manipulated pollinator access in a focal oilseed rape field in each landscape using open and closed cages. The pollinator communities in the focal fields were sampled using pan traps. The abundance of wild pollinators increased significantly with the proportion of cultivated land, but the diversity of the wild pollinator communities declined. The responses of pollinator abundance and diversity to cultivated land were best explained at scales of around 1000m. The abundance of the unmanaged honey bee Apis cerana was positively associated with the proportion of cultivated land, whereas the abundance of the managed A. mellifera was not. A pollination services index (PSI) was calculated by comparing the reproductive investment in seeds between plants with or without pollinator access. PSI was positively correlated with wild pollinator abundance, but not with the abundance of honeybee species. PSI was also not significantly correlated with the area proportion of cultivated land. Our results indicate that crop dominated landscapes with numerous small fields supported an abundant, but relatively species poor bee community that delivered pollination services to oilseed rape. Conservation of (semi-)natural habitats, however, is important for maintaining the diversity of wild pollinators.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.035
      Issue No: Vol. 246 (2017)
  • A comparison of naturally growing vegetation vs. border-planted companion
           plants for sustaining parasitoids in pomegranate orchards
    • Authors: Miriam Kishinevsky; Tamar Keasar; Ally R. Harari; Elad Chiel
      Pages: 117 - 123
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Miriam Kishinevsky, Tamar Keasar, Ally R. Harari, Elad Chiel
      Diversification of vegetation within and around agricultural habitats is an effective strategy to support populations of natural enemies of crops’ pests. Such diversification can be achieved by conservation of natural vegetation that develops spontaneously around the plots, as well as by active introduction of companion plants to the crop. In this study we compared these two approaches in pomegranate orchards in Mediterranean climate. First, we evaluated ten candidate companion plant species for their potential to attract parasitoids of pomegranate pests. We then planted a combination of the two leading species − celery and Syrian oregano − along the perimeter of five orchards. In five additional, paired orchards, no plants were added. Arthropods were sampled from added and naturally growing companion plants throughout the pomegranate fruit growth season. Parasitoids were the most common natural enemies in our samples, and their overall abundance was similar in both treatments. Pest levels did not differ between treatments either. However, the distribution of some parasitoids (Neochrysocharis and Telenomus) and pests (leafhoppers and dipteran leafminers) within the orchards was affected by the margin vegetation type: these insects were more abundant in the margins than in the centers of the orchards with companion plants (suggesting a role as trap plants), whereas the opposite was observed in orchards with natural vegetation. We conclude that introduction of companion plants and conservation of local natural vegetation were equally effective in sustaining parasitoid numbers and diversity, but that planting attracted some parasitoids away from the orchards towards their margins. This possibly provides these natural enemies with a refuge from agricultural disturbances, but might reduce their contribution to pest control.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.034
      Issue No: Vol. 246 (2017)
  • Does heterogeneity in crop canopy microclimates matter for pests? Evidence
           from aerial high-resolution thermography
    • Authors: E. Faye; F. Rebaudo; C. Carpio; M. Herrera; O. Dangles
      Pages: 124 - 133
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): E. Faye, F. Rebaudo, C. Carpio, M. Herrera, O. Dangles
      A majority of agricultural pests are influenced by microclimatic conditions that affect their performance and occurrence. Thermal heterogeneity experienced by pests at fine spatial scales is potentially a key to understand pest dynamics, yet its study over entire fields at fine resolution has never been performed. We used aerial infrared thermography to yield high-resolution measurements of crop canopy temperatures in 38 potato fields in the Ecuadorian Andes. In each field, for 30 different plots, we characterized the spatiotemporal heterogeneity of crop canopy temperatures and simultaneously sampled populations of four common leaf-surface dwelling adult pests. We then evaluated the fine-scale thermal heterogeneity implications for pest occurrence and compared a variety of thermal spatial metrics with pest abundance and richness measured in field. We found that the range of temperatures available for pests in crop canopies was independent on scale: pests can access within few centimetres most of the thermal microenvironments recorded at the field level. Also, the availability of thermal microenvironments was dependent on solar radiations: with increasing radiation levels, pests have to travel less distance to reach a variety of thermal environments. At the plot level, we found that the four-studied pests were not clumped into their optimal thermal conditions but rather distributed evenly. Pests having a wide range of favourable microenvironments available within very short distances might be constrained by others factors (resources, enemies). However, we found that pest richness was significantly correlated to both thermal aggregation and diversity index, suggesting that more diverse and distinctly distributed thermal environments in crop fields shelter a higher diversity of pests. As environmental conservation and agronomical management increasingly depend on our ability to understand and predict the responses of species to their environment, we recommend refining global pest distribution predictions using fine-grained microclimatic models to infer accurate responses of organism to climate change. Indeed, fine-scale spatiotemporal heterogeneity of microclimates might provide organisms with more than enough suitable thermal habitats in their actual location to withstand global changes.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.027
      Issue No: Vol. 246 (2017)
  • Effects of shade-tree species and spacing on soil and leaf nutrient
           concentrations in cocoa plantations at 8 years after establishment
    • Authors: Shahla Hosseini Bai; Stephen J. Trueman; Tio Nevenimo; Godfrey Hannet; Peter Bapiwai; Mathew Poienou; Helen M. Wallace
      Pages: 134 - 143
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Shahla Hosseini Bai, Stephen J. Trueman, Tio Nevenimo, Godfrey Hannet, Peter Bapiwai, Mathew Poienou, Helen M. Wallace
      Intercropping in agroforestry systems improves ecosystem services. Appropriate species compositions and spacing regimes are critical to achieve ecosystem benefits and improve yields of all the component crops. Cocoa (Theobroma cacao) is an important cash crop globally but it requires shade for survival and growth. However, the effects of shade-tree species composition and spacing regime on nutrient cycling in cocoa plantations are not well understood. This study investigated the effects of shade tree species and spacing regimes on soil and plant nutrient availability at 8 years after plantation establishment in Papua New Guinea. Three cocoa intercropping systems were established in which T. cacao was planted with either a non-legume timber tree, Canarium indicum, or a legume non-timber tree, Gliricidia sepium. The shade-tree spacing regimes included either 8m×16m or 8m×8m in the Theobroma + Canarium plantations. There was an ongoing thinning regime in the Theobroma + Gliricidia plantation, with a final shade-tree spacing of 12m×12m. Soil total carbon (TC) and total nitrogen (TN) were significantly higher in the Theobroma + Gliricidia plantation with 12m×12m spacing and the Theobroma + Canarium plantation with 8m×16m spacing than in the Theobroma + Canarium plantation with 8m×8m spacing. Foliar TN and P were correlated with soil TN and P, respectively, whereas no correlation was detected between soil and leaf K concentrations. Foliar TN, P and K were under ideal concentrations for T. cacao in all of the plantations. The Theobroma + Gliricidia plantation had higher soil water extractable phosphorus (P) than the two Theobroma + Canarium plantations, probably due to frequent pruning of the G. sepium trees. Foliar C isotope composition (δ13C) of T. cacao suggested that T. cacao close to G. sepium or close to C. indicum with spacing of 8m×16m and 8m×8m had similar light interception. However, increased C. indicum spacing increased the light interception of T. cacao trees that were not planted next to C. indicum. This study indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T. cacao. However, our study indicated all three plantations required fertilisation and better nutrient management.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.06.003
      Issue No: Vol. 246 (2017)
  • Direct recovery of 33P-labelled fertiliser phosphorus in subterranean
           clover (Trifolium subterraneum) pastures under field conditions – The
           role of agronomic management
    • Authors: Timothy I. McLaren; Therese M. McBeath; Richard J. Simpson; Alan E. Richardson; Adam Stefanski; Christopher N. Guppy; Ronald J. Smernik; Colin Rivers; Caroline Johnston; Michael J. McLaughlin
      Pages: 144 - 156
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Timothy I. McLaren, Therese M. McBeath, Richard J. Simpson, Alan E. Richardson, Adam Stefanski, Christopher N. Guppy, Ronald J. Smernik, Colin Rivers, Caroline Johnston, Michael J. McLaughlin
      Grazing systems are a major producer of food and fibre across the world. These systems often require the addition of fertiliser phosphorus (P) for maximum pasture growth, and it is now estimated that a four-fold increase in the use of P fertiliser in grasslands is needed to meet increased food demand by the year 2050. However, the recovery of P from fertiliser is often inefficient and global issues associated with P scarcity will continue to worsen. Knowledge on the uptake of fertiliser P by grasslands, including the effect of agronomic management, remains incomplete under field conditions. The aim of this study was to quantify the effects of soil P fertility (across three levels of soil P fertility), time of fertiliser application (at one level of soil P fertility), and placement of fertiliser (at one level of soil P fertility) on the growth and uptake of fertiliser P by clover pastures during a growing season. Subterranean clover (Trifolium subterraneum L.) monocultures established at two field sites in Australia were used to test the growth response to, and recovery of: (i) early-season (autumn) additions of fertiliser P to the soil surface at three levels of soil P fertility; (ii) mid-season (late winter) additions of fertiliser P to the soil surface; and (iii) early-season additions of fertiliser P placed 6cm below the soil surface. Fertiliser P was applied to the pastures as single superphosphate that was labelled with a 33P radiotracer to supply ∼20kgPha−1. Total herbage yield and recovery of fertiliser P by the clover pastures was generally highest when fertiliser P was applied to the soil surface early in the growing season and to soils maintained at the optimum level of soil P fertility for maximum pasture growth. An audit of the 33P recovery of fertiliser P in the clover pasture revealed that up to 50% of the fertiliser P was recovered by the clover plant (shoots and roots), 5–15% remained in the fertiliser granule, and 20–25% was recovered in the 0–4cm soil layer (largely as inorganic P) by the end of the growing season. We demonstrate that clover pastures are able to recover a relatively large proportion of surface applied fertiliser P during a growing season. Surface application is the simplest and most cost-effective strategy for management of fertiliser P in pastures.

      PubDate: 2017-06-11T15:04:41Z
      DOI: 10.1016/j.agee.2017.05.029
      Issue No: Vol. 246 (2017)
  • Exploring the interactions between resource availability and the
           utilisation of semi-natural habitats by insect pollinators in an intensive
           agricultural landscape
    • Authors: Lorna J. Cole; Sarah Brocklehurst; Duncan Robertson; William Harrison; David I. McCracken
      Pages: 157 - 167
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Lorna J. Cole, Sarah Brocklehurst, Duncan Robertson, William Harrison, David I. McCracken
      Intensification of agriculture and associated loss of habitat heterogeneity is a key driver of global declines in insect pollinators. Pollinators utilise different habitats to meet resource requirements throughout their life-span and it is widely accepted that their conservation requires a landscape-scale approach. Information on the mechanisms driving insect pollinators at the landscape scale is, however, lacking. To fill this knowledge gap, this novel study explores how pollinators utilise different habitats within a landscape and how utilisation changes over the season. Floral resources and insect pollinators (i.e. bumblebee, butterflies and hoverflies) were monitored during peak pollinator activity periods on a wide range of agricultural and semi-natural habitats in an intensive grassland landscape. The availability of key foraging resources differed between semi-natural habitats and this was strongly linked to their utilisation by pollinators. Floral resources were most abundant and diverse in road verges, riparian buffer strips and open scrub. These were key habitats for butterflies, with road verges and buffer strips also being important for hoverflies and bumblebees. The relative value of semi-natural habitats in providing floral resources changed throughout the season. Pollinators appeared to respond to changes in key floral resources, dynamically using different semi-natural habitats to meet their requirements. Maintaining landscape heterogeneity and improving the quality of semi-natural habitats to ensure resource diversity and continuity is fundamental to pollinator conservation. Regionally targeting agri-environment spending could result in the simplification of agricultural landscapes with consequences on insect pollinators and biodiversity as a whole.
      Graphical abstract image

      PubDate: 2017-06-17T01:56:46Z
      DOI: 10.1016/j.agee.2017.05.007
      Issue No: Vol. 246 (2017)
  • Attract and distract: Manipulation of a food-mediated protective mutualism
           enhances natural pest control
    • Authors: Felix L. Wäckers; Jesús Sánchez Alberola; Ferran Garcia-Marí; Apostolos Pekas
      Pages: 168 - 174
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Felix L. Wäckers, Jesús Sánchez Alberola, Ferran Garcia-Marí, Apostolos Pekas
      Ants can act simultaneously as predators and as protectors of honeydew producing pests. As a result, their impact on plants can be both positive and negative. By guarding honeydew producers against their natural enemies, ants can severely disrupt biological control programs and are often seen as important indirect pests. Chemical control, as well as physical ant-exclusion is employed to disrupt the mutualistic relationship between ants and honeydew producers. However, the exclusion or killing of ants also eliminates their services as biocontrol agents. Herein, we tested whether it is possible to use artificial sugar supplements to shift the balance in ant-pest interaction from pest guarding to pest control. Sugar feeders were supplied either on the ground near the tree trunk, or on the tree branches of citrus trees. Subsequently we assessed whether the provisioning of artificial sugar sources i) alters ant activity ii) disrupts the association between the ant Lasius grandis and the aphid Aphis spiraecola and iii) reduces the aphid populations over time. Compared to control trees (no sugars), ant activity within the tree was significantly reduced when the sugar feeders were placed on the ground and significantly increased when the feeders were placed on the tree branches. Ant tending of aphid colonies was reduced in all trees featuring sugar feeders. Similarly, aphid colony size was significantly reduced relative to control trees, both for trees with sugars on the ground or on the branches. However, the reduction was more pronounced when the sugars were offered on the tree branches. Finally, the abundance of natural enemies being associated with the aphid colony was significantly increased on trees with sugars on the branches. This shows that the provisioning of artificial sugar sources has practical potential as a sustainable strategy for ant management in programs aiming at the biological control of honeydew producing pests.

      PubDate: 2017-06-17T01:56:46Z
      DOI: 10.1016/j.agee.2017.05.037
      Issue No: Vol. 246 (2017)
  • Management matters: A comparison of ant assemblages in organic and
           conventional vineyards
    • Authors: Alberto Masoni; Filippo Frizzi; Carsten Brühl; Niccolò Zocchi; Enrico Palchetti; Guido Chelazzi; Giacomo Santini
      Pages: 175 - 183
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Alberto Masoni, Filippo Frizzi, Carsten Brühl, Niccolò Zocchi, Enrico Palchetti, Guido Chelazzi, Giacomo Santini
      Agriculture is one of the dominant types of soil use throughout the world, and understanding patterns of species distributions across agroecosystems is a significant challenge for the future. The intensive use of agrochemicals affects the presence and distribution of several taxa, and organic agricultural methods are believed to be more environmentally sound than conventional ones. In general, organically grown crops host higher species richness for many different taxa, although this evidence is not always unequivocal. The aim of this study was to contribute to understanding whether different management options (organic vs. conventional) affect ant assemblages in vineyards, one of the most important permanent crops in Mediterranean-type environments. To this purpose, we analyzed ant assemblages from organic and conventional vineyards in the Chianti area, Italy. To reduce confounding effects, we chose vineyards with similar soil management (frequency of tillage) and placed within a comparable habitat matrix. The results of this study showed that organic and conventional vineyards hosted a similar species pool, but the structure of their assemblages differed and the effect of insecticides particularly appears to be relevant. Both ant abundance and the number of species per unit area were significantly greater in organic than conventional vineyards. The use of insecticides appeared to be particularly relevant given that vineyards that did not use insecticides also had greater alpha and beta diversity than vineyards where these chemicals were used.

      PubDate: 2017-06-17T01:56:46Z
      DOI: 10.1016/j.agee.2017.05.036
      Issue No: Vol. 246 (2017)
  • Subtle differences in birds detected between organic and nonorganic farms
           in Saskatchewan Prairie Parklands by farm pair and bird functional group
    • Authors: David Anthony Kirk; Kathryn E. Freemark Lindsay
      Pages: 184 - 201
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): David Anthony Kirk, Kathryn E. Freemark Lindsay
      Organic farming may be more beneficial to biodiversity than nonorganic farming but the comparison is often confounded by regional within-farm and landscape differences. We compared breeding bird species composition and abundance on 10 farm pairs of each type matched at the site level for land cover in the prairie parklands of Saskatchewan, Canada in 1990. Land cover was measured around bird point counts at two extents; ‘site’ (6.3ha area) and ‘field’ (16.3ha area). We pooled species into functional groups; linear mixed models showed no significant differences between farm types for species richness but that all birds, migratory birds using crops and aerial insectivores were more abundant on organic farms. A permutational multivariate analysis of variance demonstrated that farm type did not have a significant overall effect on compositional similarity but that pairwise differences existed between about half of the farm pairs (the direction of differences in beta diversity was not consistent between organic and nonorganic farms according to tests for the homogeneity of multivariate dispersions). Farm-pair differences were more pronounced for all birds and for migratory bird species using crops, migratory birds consuming grains and ground feeders, but not grassland birds. nMDS ordinations suggested that there was more variation in species composition and abundance on organic farms than nonorganic ones but the difference was not significant. Distance-based redundancy analysis (dbRDA) was used to examine the main drivers of bird species composition and abundance and to see which extent was most important; land cover at the field extent was more important than land cover at the site extent or the farming practices measured. The most important field-extent land cover was the amount of native grassland, woodland (including shelterbelts) and wetlands. After controlling for significant field-extent land cover, seed treatment, herbicide use, and number of passes were significant. At the site extent, greater non-crop heterogeneity had a significantly positive effect on abundance and species richness of several groups (e.g., grassland birds, migratory granivores, ground feeders, ground nesters) but a negative effect on richness of woodland birds and abundance of aerial insectivores. Relationships with crop heterogeneity were mostly negative and non-significant. Overall land cover heterogeneity at the site level was positively related to the richness of grassland birds. In contrast at the field extent, non-crop heterogeneity did not have any significant effects on the richness and abundance of any functional group. Crop heterogeneity had a significantly negative effect on aerial insectivore richness and abundance. In the early 1990s, differences in birds between organic and nonorganic farms in Saskatchewan were evident but subtle and variable among farms, and apparently most related to land cover-bird assemblage interactions/relationships.

      PubDate: 2017-06-17T01:56:46Z
      DOI: 10.1016/j.agee.2017.04.009
      Issue No: Vol. 246 (2017)
  • Soil physico-hydrical properties changes induced by weed control methods
           in coffee plantation
    • Authors: L.F. Pires; C.F. Araujo-Junior; A.C. Auler; N.M.P. Dias; M.S. Dias Junior; E.N. de Alcântara
      Pages: 261 - 268
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): L.F. Pires, C.F. Araujo-Junior, A.C. Auler, N.M.P. Dias, M.S. Dias Junior, E.N. de Alcântara
      Weed management between coffee inter rows plays a key role in minimizing soil degradation processes. Soil structure and, consequently, its pore size distribution (PSD), water retention (SWRC) and availability can be greatly affected by the weed control methods. In this study, the effect of six different weed control methods on pore size distribution of a Haplustox was analyzed. Two soil depths (0–3 and 10–13cm) were investigated. Weed control methods in the inter row area were: no weed control; post-emergence herbicide (Glyphosate); mechanical mower; hand-hoe weeding; rotary tiller; pre-emergence herbicide (Oxyfluorfen). An adjacent area of native forest close to the field experiment was used as a reference. The application of different weed control methods produced alterations in the soil structure in relation to the native forest as observed by measurements of SWRC and PSD. The upper soil surface layer (0–3cm) was more sensitive to changes than the lower surface layer (10–13cm). In the inter row area (between coffee rows), the weed control methods hand hoe weeding, mechanical mower (both mechanical methods) and pre-emergence herbicide decreased the volume of pores responsible for water drainage, with equivalent pore radius >25μm, in the layer 0–3cm in relation to the 10–13cm layer.

      PubDate: 2017-06-21T13:36:13Z
      DOI: 10.1016/j.agee.2017.06.008
      Issue No: Vol. 246 (2017)
  • Regional-scale effects override the influence of fine-scale landscape
           heterogeneity on rice arthropod communities
    • Authors: Christophe Dominik; Ralf Seppelt; Finbarr G. Horgan; Leonardo Marquez; Josef Settele; Tomáš Václavík
      Pages: 269 - 278
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Christophe Dominik, Ralf Seppelt, Finbarr G. Horgan, Leonardo Marquez, Josef Settele, Tomáš Václavík
      Irrigated rice croplands are among the most biologically diverse agroecosystems globally; however, intensification and simplification of farmed areas into homogeneous monocultures can lead to biodiversity loss and a reduction of associated ecosystem services such as natural pest regulation. Understanding how landscape heterogeneity affects the diversity of arthropod communities is therefore crucial for the sustainable management of rice agroecosystems. Here, we examine the influence of fine-scale landscape heterogeneity and regional-scale effects on the arthropod communities of three rice-production regions in the Philippines. Our analysis of 213 arthropod morphospecies (37,339 individuals) collected using two sampling methods at 28 field sites indicated that the rice agroecosystems in each study region had unique arthropod assemblages, likely reflecting region-specific environmental and land-use conditions. For all sites together, we found no effect of fine-scale landscape context (classified as rather high or low heterogeneity sites) on assemblage structure (arthropod abundance, species richness or diversity). When assemblages were analyzed separately, significant effects of fine-scale landscape context were only detected in one region and for two functional groups (predators and detritivores). Elevation gradient, used as a proxy for regional-scale effects in the study regions, explained more than 60% of variance in assemblage structure. Total arthropod abundance and rarefied species richness were negatively related to elevation, suggesting that regional-scale effects rather than fine-scale landscape heterogeneity explained the composition of rice-arthropod communities in landscapes. To further disentangle the complex effects of broad-scale environmental drivers versus fine-scale landscape complexity on arthropod communities and biocontrol services, future research in rice agroecosystems should focus on a more detailed quantification of landscape heterogeneity and examine its effect at multiple spatial scales.

      PubDate: 2017-06-21T13:36:13Z
      DOI: 10.1016/j.agee.2017.06.011
      Issue No: Vol. 246 (2017)
  • The use of Ecosystem-based Adaptation practices by smallholder farmers in
           Central America
    • Authors: Celia A. Harvey; M. Ruth Martínez-Rodríguez; José Mario Cárdenas'; Jacques Avelino; Bruno Rapidel; Raffaele Vignola; Camila I. Donatti; Sergio Vilchez-Mendoza
      Pages: 279 - 290
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Celia A. Harvey, M. Ruth Martínez-Rodríguez, José Mario Cárdenas', Jacques Avelino, Bruno Rapidel, Raffaele Vignola, Camila I. Donatti, Sergio Vilchez-Mendoza
      There is growing interest in promoting the use of Ecosystem-based Adaptation (EbA) practices to help smallholder farmers adapt to climate change, however there is limited information on how commonly these practices are used by smallholder farmers and what factors influence their use. Using participatory mapping and field surveys, we examined the prevalence and characteristics of EbA practices on 300 smallholder coffee and maize farmers in six landscapes in Central America and explored the socioeconomic and biophysical factors associated with their use. The prevalence of individual EbA practices varied across smallholder farms. Common EbA practices included live fences, home gardens, shade trees in coffee plantations, and dispersed trees in maize fields. We found a mean of 3.8 EbA practices per farm. Factors that were correlated with the total number of EbA practices on farms included the mean area of coffee plantations, farmer age, farmer experience, the farm type and the landscape in which farms were located. Factors associated with the presence or characteristics of individual EbA practices included the size of coffee plantations, farmer experience, farmer education, land tenure, landscape and farm type. Our analysis suggests that many smallholder farmers in Central America are already using certain EbA practices, but there is still scope for greater implementation. Policy makers, donors and technicians can encourage the broader use of EbA by smallholder farmers by facilitating farmer-to-farmer exchanges to share knowledge on EbA implementation, assessing the effectiveness of EbA practices in delivering adaptation benefits, and tailoring EbA policies and programs for smallholder farmers in different socioeconomic and biophysical contexts.

      PubDate: 2017-06-21T13:36:13Z
      DOI: 10.1016/j.agee.2017.04.018
      Issue No: Vol. 246 (2017)
  • Isolation, characterization and selection of indigenous Bradyrhizobium
           strains with outstanding symbiotic performance to increase soybean yields
           in Mozambique
    • Authors: Amaral Machaculeha Chibeba; Stephen Kyei-Boahen; Maria de Fátima Guimarães; Marco Antonio Nogueira; Mariangela Hungria
      Pages: 291 - 305
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Amaral Machaculeha Chibeba, Stephen Kyei-Boahen, Maria de Fátima Guimarães, Marco Antonio Nogueira, Mariangela Hungria
      Soybean inoculation with effective rhizobial strains makes unnecessary the use of N-fertilizers in the tropics. A frequently reported problem is the failure of the inoculant strains to overcome the competition imposed by indigenous rhizobial populations. The screening of indigenous rhizobia, already adapted to local conditions, searching for highly effective strains for use as inoculants represents a promising strategy in overcoming inoculation failure. The objective of this study was to isolate and characterize indigenous rhizobia and to identify strains that hold potential to be included in inoculant formulations for soybean production, with both promiscuous and non-promiscuous soybean cultivars, in Mozambican agro-climatic conditions. A total of 105 isolates obtained from nodules of promiscuous soybean grown at 15 sites were screened for N2-fixation effectiveness in the greenhouse along with five commercial strains. Eighty-seven isolates confirmed the ability to form effective nodules on soybean and were used for genetic characterization by rep-PCR (BOX) and sequencing of the 16S rRNA gene, and also for symbiotic effectiveness. BOX-PCR fingerprinting revealed remarkable genetic diversity, with 41 clusters formed, considering a similarity level of 65%. The 16S rRNA analysis assigned the isolates to the genera Bradyrhizobium (75%) and Agrobacterium/Rhizobium (25%). Great variability in symbiotic effectiveness was detected among the indigenous rhizobia from Mozambique, with ten isolates performing better than the commercial strain B. diazoefficiens USDA 110, the best reference strain, and 51 isolates with lower performance than all reference strains. Thirteen of the best isolates from the first greenhouse trial were evaluated, along with the five commercial strains, in two promiscuous (TGx 1963-3F and TGx 1835-10E) and one non-promiscuous (BRS 284) soybean cultivars in a second greenhouse trial. In general the promiscous soybeans responded better to inoculation. The 13 isolates were also characterized for tolerance to acidity and alkalinity (pH 3.5 and 9.0, respectively), salinity (0.1, 0.3 and 0.5molL−1 of NaCl) and high temperatures (35, 40 and 45°C) in vitro. Five isolates, three (Moz 4, Moz 19 and Moz 22) belonging to the superclade B. elkanii and two (Moz 27 and Moz 61) assigned to the superclade B. japonicum, consistently showed high symbiotic effectiveness, suggesting that the inoculation with indigenous rhizobia adapted to local conditions represents a possible strategy for increasing soybean yields in Mozambique. Phylogenetic position of the five elite isolates was confirmed by the MLSA with four protein-coding housekeeping genes, dnaK, glnII, gyrB and recA.

      PubDate: 2017-06-21T13:36:13Z
      DOI: 10.1016/j.agee.2017.06.017
      Issue No: Vol. 246 (2017)
  • Fungal communities are differentially affected by conventional and
           biodynamic agricultural management approaches in vineyard ecosystems
    • Authors: Peter Morrison-Whittle; Soon A. Lee; Matthew R. Goddard
      Pages: 306 - 313
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Peter Morrison-Whittle, Soon A. Lee, Matthew R. Goddard
      There is increased need to identify sustainable agricultural methods which avoid environmental degradation. Previous studies have focused on the effect of specific agricultural interventions on large organisms, but we have fewer data evaluating how microbes, which are key components of ecosystems, might be affected. Additionally, previous studies have been constrained as they only examined one habitat in an ecosystem and have not gone on to evaluate the effect of agricultural approach on harvested crops. Here we take an ecosystems approach and evaluate the net effect of conventional versus biodynamic management on agricultural ecosystems by quantifying fungal communities in multiple habitats using metagenomics. We go on to measure biodiversity in the crop and key chemical quality parameters in the product consumed by humans. We find that the method of management significantly affects communities in soil, on plant structures, and on the developing crop in subtle but importantly different ways in terms of number, type, and abundance of species. However, management approach has no effect on communities in the final harvested juice, nor on product traits aligned with quality. This shows that while management approach impacts different habitats in the environment in different ways, this does not automatically flow onto the harvested crop.

      PubDate: 2017-06-21T13:36:13Z
      DOI: 10.1016/j.agee.2017.05.022
      Issue No: Vol. 246 (2017)
  • Soil carbon changes in paddy fields amended with fly ash
    • Authors: Sang-Sun Lim; Woo-Jung Choi; Scott X. Chang; Muhammad A. Arshad; Kwang-Sik Yoon; Han-Yong Kim
      Pages: 11 - 21
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Sang-Sun Lim, Woo-Jung Choi, Scott X. Chang, Muhammad A. Arshad, Kwang-Sik Yoon, Han-Yong Kim
      Increasing soil carbon (C) sequestration in the agricultural sector is an important strategy for mitigating climate change; however, conventional best management practices such as crop residue retention and organic fertilizer application do not always increase soil C content due to C loss by cultivation. In this context, application of fine-textured minerals such as coal fly ash (FA) may be effective in increasing soil C sequestration by enhancing plant biomass production and protecting soil C from being lost. We conducted a three-year field experiment in a paddy field with three levels of FA application (0, 5, and 10% by soil weight) in combination with the following four nitrogen (N) treatments: no input, and applications of urea, pig manure compost (compost) and hairy vetch (Vicia Villosa Roth.) green manure (vetch). Across the three seasons, rice grain yield was in the order of vetch=urea>compost>no input, reflecting the effect of N availability in each treatment. Application of FA (particularly at 10%) reduced the total rice plant biomass by hampering tillering. However, FA application did not reduce grain yield due to increased individual grain weight. In spite of decreased rice residue incorporation into the soil, FA application increased the soil C content at the end of the third season regardless of the N source, driven by reduced soil C loss. We conclude that the application of mineral soil amendments such as FA is effective in enhancing soil C sequestration without decreasing rice yield in paddy fields.
      Graphical abstract image

      PubDate: 2017-05-17T12:06:45Z
      DOI: 10.1016/j.agee.2017.03.027
      Issue No: Vol. 245 (2017)
  • Spatio-temporal patterns of soil organic carbon and pH in relation to
           environmental factors—A case study of the Black Soil Region of
           Northeastern China
    • Authors: Yang Ou; Alain N. Rousseau; Lixia Wang; Baixing Yan
      Pages: 22 - 31
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Yang Ou, Alain N. Rousseau, Lixia Wang, Baixing Yan
      The Northeastern Black Soil Region plays a key role in food supply in China. Identifying spatio-temporal variation of soil properties as influenced by environmental factors has become essential for future agricultural development. A total of 5891 topsoil samples (0–20cm) were collected and soil organic carbon (SOC) and pH were measured in the Jilin Province. Geostatistics, multiple linear regression, and redundancy analysis (RDA) were used to highlight the spatio-temporal patterns of SOC and pH and determine the relationship with environmental factors. Results showed that from 1980 to 2010 average level of SOC increased by 2.68gkg−1 (p <0.001). However, in the Golden-Maize-Belt Counties (i.e., the major grain-producing areas of the Jilin Province), the SOC content rapidly decreased, the largest drop reaching 24.83gkg−1. Over the past thirty years, pH values slightly increased (0.30; p >0.05) throughout the province. Environmental factors could explain 64% and 78% of the spatial patterns of SOC and pH, respectively. The principal factors impacting SOC and pH included: precipitation, gully density, forested land and grain yield. There was significant covariation between natural and human factors in forming these spatial patterns. Anthropogenic disturbance had a larger influence on the distribution of SOC than on the distribution of pH.

      PubDate: 2017-05-17T12:06:45Z
      DOI: 10.1016/j.agee.2017.05.003
      Issue No: Vol. 245 (2017)
  • Evaluating the effect of shade trees on provision of ecosystem services in
           intensively managed coffee plantations
    • Authors: Louise Meylan; Christian Gary; Clémentine Allinne; Jorge Ortiz; Louise Jackson; Bruno Rapidel
      Pages: 32 - 42
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Louise Meylan, Christian Gary, Clémentine Allinne, Jorge Ortiz, Louise Jackson, Bruno Rapidel
      Intensively managed cropping systems with emphasis on productivity of the main crop can benefit from additional ecosystem services brought by integration of trees in the system − but potential drawbacks must also be accounted for. In an on-farm study, we used a variety of plant, soil and water- related variables to assess the effect of Erythrina spp. and Musa spp. on the provision of ecosystem services in productive, high-quality Coffea arabica plantations in Costa Rica. We found 1) no significant effect of shade trees on coffee production overall; 2) evidence that shade trees do affect flowering and subsequent cherry development, with effects strongly dependent on climate and annual variations in coffee plant physiology; 3) Erythrina shade trees significantly increased soil litter and relative infiltration rate of water in the soil, both linked to soil conservation and decrease in erosion; 4) even in highly fertilized environments, Erythrina trees do fix N which was taken up by adjacent coffee plants. The lack of significant negative effect of shade trees on overall coffee yield and the observation of the provision of other useful services was not unexpected, because of 1) the low density of shade trees in the study site (100–350 trees/ha pruned twice a year on average) and 2) the sensitivity of coffee yields to other interacting effects such as climate, pests and diseases and physiological variations in the plant. Pending further long-term research into the factors affecting coffee yield, we find shade trees provide sufficient ecosystem services to justify their integration in even intensively managed plantations.

      PubDate: 2017-05-17T12:06:45Z
      DOI: 10.1016/j.agee.2017.05.005
      Issue No: Vol. 245 (2017)
  • Native communities of arbuscular mycorrhizal fungi associated with
           Capsicum annuum L. respond to soil properties and agronomic management
           under field conditions
    • Authors: Santos Carballar-Hernández; Laura Verónica Hernández-Cuevas; Noé Manuel Montaño; John Larsen; Ronald Ferrera-Cerrato; Oswaldo R. Taboada-Gaytán; Alba Mónica Montiel-González; Alejandro Alarcón
      Pages: 43 - 51
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Santos Carballar-Hernández, Laura Verónica Hernández-Cuevas, Noé Manuel Montaño, John Larsen, Ronald Ferrera-Cerrato, Oswaldo R. Taboada-Gaytán, Alba Mónica Montiel-González, Alejandro Alarcón
      We examined the effects of agronomic management (low, moderate, and high inputs) and soil properties on arbuscular mycorrhizal fungi (AMF) community structure collected from the rhizosphere of Capsicum annuum cultivated in six agroecosystems in Mexico. Chemical and physical soil parameters differed among agroecosystems. Native communities of AMF-morphospecies differed between agroecosystems depending on intensity of agronomic practice. In total 33 AMF-morphospecies were identified (11genera, and seven families). Soil P availability and pH negatively affected the distribution and abundance of the AMF species. High input management resulted in significant modifications in the composition and structure of the AMF communities. Agroecosystems with high or moderate input management showed 35% less AMF-morphospecies when compared to low input management systems. The most diverse AMF community was observed from agroecosystems with either moderate or low input management. Funneliformis geosporum, Claroideoglomus claroideum and C. luteum were the predominant species observed in this study. High similarity (>75%) in the structure of AMF communities among agroecosystems was found, which suggest that the observed differences between AMF communities from agroecosystems with high input management compared to that from low and moderate input management, may be due to changes in species composition.

      PubDate: 2017-05-17T12:06:45Z
      DOI: 10.1016/j.agee.2017.05.004
      Issue No: Vol. 245 (2017)
  • Greenhouse gas mitigation potential of annual and perennial dairy feed
           crop systems
    • Authors: Muhammad F. Sulaiman; Claudia Wagner-Riddle; Shannon E. Brown; Jon Warland; Paul Voroney; Philippe Rochette
      Pages: 52 - 62
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Muhammad F. Sulaiman, Claudia Wagner-Riddle, Shannon E. Brown, Jon Warland, Paul Voroney, Philippe Rochette
      Dairy production constitutes a significant amount of the total global anthropogenic greenhouse gas (GHG) emission. One of the proposed strategies to mitigate GHG emission from dairy production is by enhancing soil carbon sequestration through promoting the growing of perennial over annual dairy feed crop. We determined the net ecosystem carbon budget (NECB) of a hay and corn field grown side-by-side over three years to compare the GHG mitigation potential of perennial over annual feed crops in Elora, Ontario, Canada. The NECB was determined using measurements of net ecosystem exchange (NEE), total plant carbon content, and carbon content in applied dairy manure. The greenhouse gas balance (GHGB) were determined using the NECB plus the total nitrous oxide (N2O) fluxes measured by a complementary study at the same site. The effect of plowing of the hay field on the NECB and GHGB was also investigated. Our observations indicate that on average over the three study years, NECB of hay (7±51gCm−2 yr−1) was significantly lower than corn (154±79gCm−2 yr−1) indicating that corn was a larger carbon source than hay. The three-year average GHGB of 796 and 127gCO2-eqm−2 yr−1 for corn and hay, respectively, indicated that corn was a larger emitter of GHG than hay. The NECB was the more dominant factor than N2O emissions in influencing the outcome of the annual GHGB. We conclude that hay has a larger potential than corn in sequestering carbon and mitigating GHG emission even when emissions from hay plow-down are included.

      PubDate: 2017-05-23T12:18:52Z
      DOI: 10.1016/j.agee.2017.05.001
      Issue No: Vol. 245 (2017)
  • Soil organic carbon changes after deforestation and agrosystem
           establishment in Amazonia: An assessment by diachronic approach
    • Authors: Kenji Fujisaki; Anne-Sophie Perrin; Bernard Garric; Jérôme Balesdent; Michel Brossard
      Pages: 63 - 73
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Kenji Fujisaki, Anne-Sophie Perrin, Bernard Garric, Jérôme Balesdent, Michel Brossard
      Deforestation and agrosystem establishment can alter soil organic carbon (SOC) stocks, leading to greenhouse gases emissions and fertility losses, however SOC response has great variability. In the humid tropics like the Amazonia biome, carbon inputs from agrosystems are rarely quantified and described, despite their major contribution to the SOC dynamics after deforestation. We assessed SOC dynamics with repeated measurements in the layer 0–30cm until five years after deforestation in a diachronic site in French Guiana, cleared with a fire-free method associated to large woody debris inputs. Three agrosystems were studied: one year maize/soybean rotation with disk tillage (DT) and without tillage (NT), and a mowed grassland (G). Aboveground carbon inputs from agrosystems were measured. In addition to SOC stocks assessment, we measured roots carbon stocks, and performed δ13C measurements in grassland soil. We found a transient SOC stock increase until 1.5 years after deforestation because of large woody debris inputs from deforestation method, but these C inputs were rapidly mineralized and poorly contributed to SOC stocks 5 years after deforestation. SOC stocks in grassland did not differ from forest despite large hay exports. Thanks to large root-derived carbon inputs, C4-SOC stock in grassland was 10.4tha−1 5 years after deforestation (18.7% of the SOC stock). In annual crops, 5 years after deforestation, SOC stocks decreased on average by 18.6% compared to forest. SOC stocks did not differ according to soil tillage since aboveground carbon inputs were similar in DT and NT systems. Lower SOC stocks in annual crops compared to grassland is explained by lower carbon restitutions and by higher mineralization rate of organic matter.

      PubDate: 2017-05-23T12:18:52Z
      DOI: 10.1016/j.agee.2017.05.011
      Issue No: Vol. 245 (2017)
  • Crop cultivar affects performance of herbivore enemies and may trigger
           enhanced pest control by coaction of different parasitoid species
    • Authors: Karsten Mody; Jana Collatz; Anna Bucharova; Silvia Dorn
      Pages: 74 - 82
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Karsten Mody, Jana Collatz, Anna Bucharova, Silvia Dorn
      Pest control by naturally occurring predators and parasitoids is an ecosystem service that may benefit from greater diversity of the pest’s natural enemies. Co-occurrence of different enemy species, which act as service providers, can increase or stabilize pest control. Simultaneous cultivar diversity in varietal mixtures might foster such service providers, and the diverse cultivars might finally profit from occurrence of different natural enemies. Here, we tested how the ecosystem service pest control may be influenced by different crop cultivars and by the action of different parasitoid species. We investigated naturally occurring control of an apple pest, the apple blossom weevil Anthonomus pomorum (Curculionidae), by the parasitoid wasp species Scambus pomorum (Ichneumonidae) and Bracon variator (Braconidae) on five different cultivars (genotypes) of domestic apple Malus domestica in an organic orchard ecosystem. We quantified parasitism of the apple blossom weevil on the apple cultivars at three different times during the pest’s development period. We evaluated whether apple cultivar and pest developmental status lead to comparable or to divergent parasitism patterns by different wasp species. We further assessed size and sex ratio of the wasps to estimate their performance and biocontrol potential on different cultivars. We found that pest parasitism was increased and homogenized across cultivars by coaction of the two wasp species, which belong to the same guild and contributed differently to parasitism – (i) with progressing time and (ii) on the different cultivars. Furthermore, female size differed significantly between cultivars for both wasp species, and it followed the preference-performance hypothesis for S. pomorum, where it was positively related to parasitism. Repeated sampling revealed that only the last sampling (shortly before adult weevil emergence) provides a complete estimate of effective parasitism by both wasp species. In conclusion, intraspecific variation among crop cultivars can result in divergent performance of parasitoids, and it may trigger enhanced pest control through different parasitoid species. The coaction of different species may thus contribute to maximization and stabilization of pest control in heterogeneous cropping systems.

      PubDate: 2017-05-23T12:18:52Z
      DOI: 10.1016/j.agee.2017.05.009
      Issue No: Vol. 245 (2017)
  • Conversion of cropland to forage land and grassland increases soil labile
           carbon and enzyme activities in northeastern China
    • Authors: Pujia Yu; Shiwei Liu; Kexin Han; Shengchao Guan; Daowei Zhou
      Pages: 83 - 91
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Pujia Yu, Shiwei Liu, Kexin Han, Shengchao Guan, Daowei Zhou
      Soil labile carbon (C) and enzyme activities are valuable indicators of changes in soil quality and health. Understanding the changes in soil labile C and enzyme activities under different land uses is important to maintain soil quality and health and for sustainable land use. The primary objective of this study was to investigate the short-term influences of different land uses on SOC, soil labile C and enzyme activities in semiarid alkaline grassland of northeastern China. The experiment was organized as a block design with four replications of each land use treatment. Land use treatments were corn cropland (Corn), alfalfa forage land (Alfalfa), Lyemus chinensis grassland (AG), Lyemus chinensis grassland for mowing (AG+Mow) and restored grassland (RG), which were applied for five years. Total soil organic carbon (SOC), three labile C pools (oxidizable labile C; water-extractable organic C; microbial biomass C) and the activities of four soil enzymes (catalase; urease; alkaline phosphatase; invertase) were determined at the 0–20cm depth in the five land use treatments. Results showed that soil labile C and enzyme activities were sensitive indicators of land use change. Conversion of cropland to forage land and grassland increased SOC (40.42%), soil labile C measures (25.50%) and enzyme activities (55.60%). However, the responses of different forms of soil labile C and enzyme activities to different land uses were not similar. Under Corn, AG+Mow, AG and RG land uses, the geometric means of labile C (27.01%, 10.95%, 17.52% and 5.11%, respectively) and enzyme activities (40.92%, 13.54%, 11.38% and 7.38%, respectively) were lower than those under Alfalfa, demonstrating that soil labile C and enzyme activities improved more under Alfalfa than under other land uses in northeastern China. Significant correlations were also obtained between SOC, soil labile C measures and enzyme activities. To conclude, soil labile C and enzyme activities can be expected to gradually increase with the conversion of cropland to grasslands and forage land, and planting to alfalfa offers a profitable and sustainable solution to our requirement for pairing forage production with rapid restoration of soil quality in the areas in which soils are not suitable for growing crops in the Songnen Grassland.
      Graphical abstract image

      PubDate: 2017-05-28T09:51:36Z
      DOI: 10.1016/j.agee.2017.05.013
      Issue No: Vol. 245 (2017)
  • Approaches for evaluating subsurface phosphorus loss potential from soil
    • Authors: Biswanath Dari; Vimala D. Nair; Willie G. Harris
      Pages: 92 - 99
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Biswanath Dari, Vimala D. Nair, Willie G. Harris
      The importance of subsurface phosphorus (P) transport in deterioration of surface water quality is well documented. Practices and treatments have been identified and modeling approaches have been implemented to decrease the subsurface P load to surface waters. Soil phosphorus storage capacity (SPSC) is a site-assessment tool that predicts the potential for P loss from soils. We examined the use of SPSC to assess soil profile P distributions and loss potentials for two contrasting soil types: manure-impacted Spodosols and Ultisols. Our specific objectives were to (i) validate prediction of the Langmuir P bonding strength, KL, the Freundlich adsorption coefficient, KF, or the linear adsorption coefficient, KD, of Spodosols (Ap, E and Bh horizons) and Ultisols (Ap, E and Bt horizons) using SPSC-based equations developed for surface and sub-surface horizons (Ap, E and Bt) of Ultisols and (ii) identify factors affecting retention and release of P. Results showed that SPSC derived from oxalate-extractions data can effectively predict P isotherm parameters used in P transport models. The SPSC also captured differences between soil horizons within a profile pertinent to P loss. Magnesium (Mg) and calcium (Ca) concentrations related to negative SPSC, likely due to the presence of these components in dairy manure. The initial sorbed P in the solid phase (S0) of both soil types was related to soil components such as Mg, Ca and total P when SPSC was positive. The equations developed from A, E and Bt horizons of Ultisol relating isotherm parameters to the PSR and SPSC made successful predictions for all horizons of Ultisols sampled from locations different from those in the current study and Spodosols suggesting that such equations might be applicable across a wide range of soils.

      PubDate: 2017-05-28T09:51:36Z
      DOI: 10.1016/j.agee.2017.05.006
      Issue No: Vol. 245 (2017)
  • The nature of biogenic Si and its potential role in Si supply in
           agricultural soils
    • Authors: Richard J. Haynes
      Pages: 100 - 111
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Richard J. Haynes
      Although the biogenic pool of Si in soils is known to be of central importance to plant uptake and Si cycling in natural forest and grassland ecosystems, its role in agricultural systems is controversial and unclear. The biogenic pool is mainly composed of phytogenic (plant-derived) amorphous silica (deposited in plant shoots as phytoliths) but there are also minor components of zoogenic, microbial and protistic silica. In natural ecosystems the pool of biogenic Si in the soil is typically several orders of magnitude greater than annual plant uptake so slow dissolution of this Si pool supplies the plant with Si (as silicic acid) while litter fall replenishes the pool with newly-formed phytolith Si. However except for grazed pastures, such cycling of Si is much decreased under agriculture because phytolith Si is removed from the field in harvested products and crop residues. For graminaceous crops, which commonly accumulate Si and are Si responsive (e.g. rice and sugarcane) only about 20% of accumulated Si is present in harvested products (e.g. harvested grain or cane) and the remaining 80% is present in harvest residues (straw or cane trash). The extent of phytolith Si removal, and thus rate of diminution of the biogenic pool of soil Si, is therefore greatly dependant on the magnitude of Si uptake by the crop and whether crop residues are retained or removed. Where crop residues are regularly returned to the soil, and for pastoral soils, biogenic Si will remain a significant source of potentially available Si. Thus, in addition to routine soil tests for Si using neutral salt or acidic reagents, an additional broad estimate of biogenic Si (e.g. alkali-soluble Si) is likely to improve evaluation of potentially plant available Si in many agricultural soils.

      PubDate: 2017-05-28T09:51:36Z
      DOI: 10.1016/j.agee.2017.04.021
      Issue No: Vol. 245 (2017)
  • Impact of cover cropping and landscape positions on nitrous oxide
           emissions in northeastern US agroecosystems
    • Authors: Zhen Han; M.Todd Walter; Laurie E. Drinkwater
      Pages: 124 - 134
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Zhen Han, M.Todd Walter, Laurie E. Drinkwater
      The environmental benefits of organic farming compared to conventional agriculture are well documented, but relatively few studies have assessed their differences in emissions of nitrous oxide (N2O), a potent greenhouse gas (GHG). The objective of the study was to assess the interactive impact of management and landscape positions on soil characteristics and N2O emissions. A field-scale experiment was conducted in two adjacent grain farms in upstate New York that have both undergone the same management for 20 years. In the conventional field (CNV), inorganic fertilizer was the only nitrogen (N) source, but in the organic fields (ORG), a legume cover crop, red clover (Trifolium pratense), was frost-seeded into a winter grain (spelt, Triticum spelta), and then incorporated in spring as a N source for the subsequent maize plants (Zea mays). Measurements of soil properties and N2O emissions were conducted at shoulder and toeslope positions on both CNV and ORG fields in 2012. Based on Principal Component Analysis, landscape position, management regime, and rotation phases explained 67% of the variation in the soil properties; these three major sources of variation in soil properties (principal components) were correlated significantly with seasonal average N2O emissions. Comparable N2O emissions were found from the clover-maize (ORG Cl-M) phase in the ORG field and the bare fallow-maize phase in the CNV field. The spelt-clover phase in the ORG field had the lowest N2O emissions due to low N availability. In the CNV field, seasonal average N2O emissions were driven mainly by the elevated gas fluxes after fertilizer application. High soil moisture and inorganic N pools towards the end of the growing season probably resulted in increased denitrification rates. The impact of landscape position on N2O emissions was mainly found in the CNV field, probably because greater moisture and pH drove greater rates of complete denitrification at toeslope positions. In the ORG Cl-M phase, the seasonal average N2O emissions were dominated by the emission peaks that immediately followed incorporation of clover. Greater clover biomass at shoulder slope positions resulted in greater N2O peaks there, but the position effect was not statistically significant. Our study suggests that ecosystem state factors, such as landscape characteristics, interacted with management practices to impact soil properties, crop growth, and microbial communities and, therefore, had interactive effects on N dynamics, including N2O emissions.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.018
      Issue No: Vol. 245 (2017)
  • Carbon saturation and assessment of soil organic carbon fractions in
           Mediterranean rainfed olive orchards under plant cover management
    • Authors: J.L. Vicente-Vicente; B. Gómez-Muñoz; M.B. Hinojosa-Centeno; P. Smith; R. Garcia-Ruiz
      Pages: 135 - 146
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): J.L. Vicente-Vicente, B. Gómez-Muñoz, M.B. Hinojosa-Centeno, P. Smith, R. Garcia-Ruiz
      Olive groves are undergoing a marked change in the way that inter-row land is managed. The current regulation and recommendation encourages the implementation of plant cover, mainly to improve soil fertility and reduce erosion. However, there is no quantitative information on the dynamics and pools of soil organic carbon (SOC) fractions of different protection levels of the plant-residue-derived organic carbon (OC). This study was conducted to provide a range of annual OC inputs in commercial olive oil groves under natural plant cover, to assess the influence of the annual application of aboveground plant cover residues on unprotected and physically, chemically and biochemically protected SOC. In addition, we tested the carbon saturation hypothesis under plant cover. Ten olive oil orchards under plant cover management (PC), together with five comparable bare soil olive oil orchards (NPC) were selected and annual aboveground natural plant residues and SOC pools were sampled and quantified. Annual aboveground plant cover biomass and OC production in PC olive orchards averaged 1.48tdry-weight (DW)ha−1 and 0.56tCDWha−1, respectively with a great variability among sites (coefficient of variation of about 100%). SOC concentration in PC orchards was, on average, 2.8 (0–5cm soil) and 2.0 (5–15cm) times higher than in bare soils of NPC, and the pool of protected SOC in the top 15cm was 2.1 times higher in the PC (17.9mgCg−1 ±5.7) (±standard deviation) compared to NPC (8.5mgCg−1 ±2.9) olive orchards. Linear or saturation type relationships between each SOC fraction and total SOC content for the range of SOC of the commercial olive oil orchards were statistically indistinguishable, and thus linear models to predict SOC accumulation due to plant cover in olive orchards are suitable, at least for the studied range of SOC. Overall, at regional scale where olive oil groves represent a very high proportion of the agricultural land, the use of plant cover appears to be a promising practice that promotes protection of the SOC, thus improving SOC sequestration.

      PubDate: 2017-06-02T09:27:54Z
      DOI: 10.1016/j.agee.2017.05.020
      Issue No: Vol. 245 (2017)
  • The challenge of imbalanced nutrient flows in organic farming systems: A
           study of organic greenhouses in Southern Germany
    • Authors: Sabine Zikeli; Lucia Deil; Kurt Möller
      Pages: 1 - 13
      Abstract: Publication date: 15 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 244
      Author(s): Sabine Zikeli, Lucia Deil, Kurt Möller
      Organic greenhouse vegetable production is characterized by very high nutrient demands within short growing periods and high nutrient exports via products sold. Therefore, meeting crop nutrient demands and maintaining long-term sustainability in these systems is highly challenging. To gain insight in current practices this study assessed fertilization strategies and nutrient flows of ten organic horticultural farms (22 greenhouses and polytunnels) in Southwest Germany belonging to the two organic farming associations Bioland and Demeter (biodynamic) for a cropping period of three years. Soil samples were taken to analyze plant available phosphorus, potassium, soil organic carbon, pH and salinity. Crop rotations in the greenhouses were very diverse, though focused on tomatoes. Depending on association membership, fertilization was based either on the use of solid animal manures (26.1Mgha−1 a−1) and composts (7.9Mgha−1 a−1) for the biodynamic Demeter farms or on commercial complementary fertilizers on the Bioland farms (e.g. keratin products, food industry waste products). All farms showed strong imbalances in their nutrient flows with high average surpluses for all nutrients (197kgha−1 a−1 for nitrogen, 47.9kgha−1 a−1 for phosphorus, 119kgha−1 a−1 for sulfur) except potassium with an average deficit of 143kgha−1 a−1 and low nitrogen use efficiencies. In addition, a risk for increased soil alkalinity and salinity existed and concentrations of plant available phosphorus in the soil were very high (average 332mg phosphorus kg−1). The results show that today’s fertilization strategies for organic greenhouses are not sustainable, which calls for a thorough revision of the core ideas on soil fertility in the organic horticultural sector.

      PubDate: 2017-05-03T05:03:46Z
      DOI: 10.1016/j.agee.2017.04.017
      Issue No: Vol. 244 (2017)
  • Meadows species composition, biodiversity and forage value in an Alpine
           district: Relationships with environmental and dairy farm management
    • Authors: Mario Enrico Pierik; Fausto Gusmeroli; Gianpaolo Della Marianna; Alberto Tamburini; Stefano Bocchi
      Pages: 14 - 21
      Abstract: Publication date: 15 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 244
      Author(s): Mario Enrico Pierik, Fausto Gusmeroli, Gianpaolo Della Marianna, Alberto Tamburini, Stefano Bocchi
      Alpine meadows have been exposed to relevant management shifts in the last decades, with changes in plant species composition and biodiversity losses often occurring in favor of augmented foraging capabilities, especially in marginal rural contexts. In this study, we analyzed the relationships among the plant species composition, biodiversity and forage value of meadows and two sets of variables, environmental and management ones, in a dairy district of the Central Italian Alps. Results indicate that management variables could only explain limited variability of the meadows under study: for instance, the number of cuts per year is available to justify the plant species composition and biodiversity of such coenoses. Moreover, the environmental variables better described the variability of responses, due to the harsh environmental constraints of the area under examination, located at high altitudes. The shared effects of the two sets explained larger variance than the management set alone, due to the complex relationships of environmental and management factors in the context. The forage value of meadows, an indicator of hay quality, was found negatively associated with the Shannon Index. This behavior highlights a known dilemma which especially refers to high altitude communities as the ones under study, clearly highlighting trade-offs between their production and biodiversity. Some taxa as Anthriscus sylvestris, Heracleum sphondylium and others critically unbalance the species composition of meadows, thus their overall biodiversity, at low altitudes. This finding, explainable by the late first cuttings commonly adopted by all farmers, suggests the eutrophication of coenoses. The management choices inspected did not reflect on the wide variability of meadows, but indeed they made possible to understand how this farming system should be deeply revised, with respect to environmental constraints and meadows’ fodder capabilities.

      PubDate: 2017-05-03T05:03:46Z
      DOI: 10.1016/j.agee.2017.04.012
      Issue No: Vol. 244 (2017)
  • Ecosystem service delivery of agri-environment measures: A synthesis for
           hedgerows and grass strips on arable land
    • Authors: Van Vooren Laura; Reubens Bert; Broekx Steven; De Frenne Pieter; Nelissen Victoria; Pardon Paul; Verheyen Kris
      Pages: 32 - 51
      Abstract: Publication date: 15 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 244
      Author(s): Van Vooren Laura, Reubens Bert, Broekx Steven, De Frenne Pieter, Nelissen Victoria, Pardon Paul, Verheyen Kris
      In north western Europe, agricultural systems are generally managed to maximize the potential delivery of provisioning ecosystem services. This has often been at the expense of other ecosystem services. Because the current supply of most ecosystem services is insufficient to meet the increasing demand, particular attention to ecosystem service delivery and hence multifunctionality in agriculture is vital. In this paper, we quantitatively assessed the impact of hedgerows and grass strips bordering parcels with annual arable crops on the simultaneous delivery of a set of ecosystem services and from there we identified synergies and trade-offs on virtual parcels. After a systematic literature search, mixed models were applied on observations from 60 studies and quantitative effect relationships between ecosystem service delivery and hedgerow and grass strip characteristics were developed. Next to the hedgerow, until a distance of twice the hedgerow height, arable crop yield was reduced by 29%. Beyond this distance, until 20 times the hedgerow height, crop yield was increased by 6%. Compared to a similar arable parcel without hedgerow or grass strip, soil carbon stock was 22% higher in the hedgerow, on average 6% higher in the adjacent parcel next to the hedgerow and 37% higher in the upper 30cm soil layer in the grass strip. Both hedgerows and grass strips intercepted nitrogen from the surface (69% and 67%, respectively) and subsurface (34% and 32%, respectively) flow and phosphorus (67% and 73%, respectively) and soil sediment (91% and 90%, respectively) from the surface flow. More natural predator species were found on parcels with hedgerows, but the number of predators was unaffected. On parcels with grass strips, both predator density and diversity was higher and aphid density was reduced. Our calculations on parcel level indicate that the trade-off between arable crop yield and regulating ecosystem services depends on hedgerow width and height and parcel dimensions. A similar trade-off is found on parcels with grass strips, but increasing grass strip width results in a proportionally higher delivery of regulating ecosystem services.

      PubDate: 2017-05-08T05:24:28Z
      DOI: 10.1016/j.agee.2017.04.015
      Issue No: Vol. 244 (2017)
  • Stable isotopes of soil water: Implications for soil water and shallow
           groundwater recharge in hill and gully regions of the Loess Plateau, China
    • Authors: Hongbing Tan; Zihao Liu; Wenbo Rao; Haizhen Wei; Yudong Zhang; Ben Jin
      Pages: 1 - 9
      Abstract: Publication date: 1 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 243
      Author(s): Hongbing Tan, Zihao Liu, Wenbo Rao, Haizhen Wei, Yudong Zhang, Ben Jin
      There is relatively abundant groundwater in some hill and gully regions of the Loess Plateau aquifer. The region has an arid to semiarid climate with low precipitation and high potential evaporation, and thus, groundwater recharge processes remain unclear. This study aimed to investigate recharge mechanisms and soil water movement in the Loess Plateau aquifer and to assess the recharge to shallow loess aquifers using soil profiles. In general, we found that the δ18O and δ2H values of soil water varied both with season and with soil profile depth. The seasonal stable isotopic values in the soil profiles also differed between wet and dry years. In particular, soil water and groundwater isotopic values responded to precipitation. This response suggests that seasonal precipitation is the main source of recharge to soil water and groundwater and that soil water is involved in groundwater recharge. The precipitation infiltration, soil water replenishment, and groundwater recharge are complicated processes. Two main modes of infiltration allow water to move downward through the unsaturated zone and recharge groundwater can be concluded. The primary mode is preferential infiltration through microtopographic features. This channel-like infiltration can rapidly move precipitation downward to deep soil layers, greatly reducing evaporation even under the arid to semiarid conditions of the study area. The secondary mode is a combination of matrix flow, which includes inside preferential infiltration though finger-like flow in the upper layer and piston-like flow in the deeper layer. The upper finger-like flow can cause rapid infiltration to below the root zone during less intense rain or snowmelt. The annual precipitation through preferential flow is the dominant recharge mode for the shallow groundwater in the loess aquifers. These two modes of recharge maintain perennial groundwater in the arid to semiarid hill and gully regions of the Loess Plateau.

      PubDate: 2017-04-11T21:01:24Z
      DOI: 10.1016/j.agee.2017.04.001
      Issue No: Vol. 243 (2017)
  • Effects of competition and climate on a crop pollinator community
    • Authors: Anders Nielsen; Trond Reitan Andreas Rinvoll Anne Brysting
      Abstract: Publication date: 1 August 2017
      Source:Agriculture, Ecosystems & Environment, Volume 246
      Author(s): Anders Nielsen, Trond Reitan, Andreas W. Rinvoll, Anne K. Brysting
      Plant-pollinator interactions are ubiquitous in nature where both wild and domesticated pollinators interact with wild plant communities and entomophilous crops. Honeybees are important pollinators in many crop systems, but recent declines in honeybee stocks in Europe and the US have caused concern about the sustainability of crop systems solely depending on honeybees. In addition, several studies have shown that honeybees might negatively affect native pollinator populations, bumblebees in particular. Here we have studied flower visitation to two raspberry farms and surrounding wildflower communities in SE Norway. Bumblebees were excluded from the raspberry field by means of exploitative competition from honeybees ( >97% of flower visits in the raspberry fields were conducted by honeybees). More than 55% of the visits recorded in wild plant communities surrounding the farms were conducted by bumblebees, showing that bumblebees were present in the system. Pollinator taxa were affected differently by temperature; honeybee visits showed a unimodal relationship with maximum flower visitation activity at a temperature of 24.1°C, while flower visits by bumblebees showed a positive, linear relationship with temperature. The effect of temperature was much weaker for bumblebees than for honeybees (∼2.2% of the variation was explained by temperature, compared to ∼46% for honeybees). Farming practice affected flower visitation, as flowers within growing tunnels received fewer visits. However, the number of flower visits, also within the growing tunnels, was far above what other studies have shown to be sufficient for optimal pollination in raspberry. We conclude that the raspberry fields were sufficiently pollinated by honeybees but that the system should be considered vulnerable as it is solely dependent on this particular pollinator species. The honeybees were sensitive to ambient temperature suggesting that they might suffer more from future climate change than bumblebees.

      PubDate: 2017-06-17T01:56:46Z
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245

      PubDate: 2017-06-17T01:56:46Z
  • Risks of phosphorus runoff losses from five Chinese paddy soils under
           conventional management practices
    • Authors: Lingling Hua; Jian Liu Limei Zhai Bin Fulin Zhang Hongyuan
      Abstract: Publication date: 1 July 2017
      Source:Agriculture, Ecosystems & Environment, Volume 245
      Author(s): Lingling Hua, Jian Liu, Limei Zhai, Bin Xi, Fulin Zhang, Hongyuan Wang, Hongbin Liu, Anqiang Chen, Bin Fu
      Phosphorus (P) runoff from arable land is a major cause for eutrophication of many surface waters. However, relatively little research has been conducted on managing P in rice (Oryza sativa L.) production systems, where farming practices differ from those of upland cropping systems due to water ponding on the soil surface (field ponding water; FPW). Because FPW is a direct source of surface runoff, identifying the main source of P and the critical period of high P concentrations in the FPW provide important insights to mitigating P runoff losses. In this study, field monitoring and laboratory incubation experiments were combined to evaluate how soil P content and conventional P fertilizer application affected FPW P concentrations in rice–wheat (Triticum aestivum L.) rotation systems of five Chinese rice producing regions. All soils had Olsen-P concentrations (10.1–20.5mgkg−1) well below the critical levels (30–172mgkg−1) for promoted risks of P loss. However, conventional P application rate significantly elevated FPW P concentrations compared to no P application, and P fertilizer contributed 47–92% of total P (TP) and 59–97% of total dissolved P (TDP) in the FPW. Temporarily, both TP and TDP concentrations peaked one day after P application (0.15–8.90mg TP L−1 and 0.16–4.49mg TDP L−1), then decreased rapidly and stabilized five days later. We conclude that fertilizer is the major source of P loss in Chinese rice production systems, and that P fertilizer rate should be optimized to reduce P concentrations in the effluent water in the first week following P application.
      Graphical abstract image

      PubDate: 2017-05-28T09:51:36Z
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: 15 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 244

      PubDate: 2017-05-17T12:06:45Z
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: 1 June 2017
      Source:Agriculture, Ecosystems & Environment, Volume 243

      PubDate: 2017-05-08T05:24:28Z
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