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Showing 1 - 200 of 3043 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 18, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 83, 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: 332, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 1)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 211, 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: 23, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 4, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 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: 8, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 129, 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: 25, 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: 22, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 25, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in 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: 10, 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: 41, 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: 47, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21, 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: 25)
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: 35, 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: 5)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 2)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 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: 24, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 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: 60)
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: 345, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 7, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 30, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 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: 309, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 5, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 8, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 405, 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: 53, 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: 6)
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: 4, 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: 7, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 48, 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: 48, 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: 38, 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: 16, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 31, 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: 33, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 46, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 191, 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: 3)
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: 26, 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: 34, 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: 55, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 10)
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: 162, 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: 11)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 1)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 22, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 157, 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   (Followers: 1, 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]   [53 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0167-8809 - ISSN (Online) 1873-2305
   Published by Elsevier Homepage  [3043 journals]
  • Earthworm communities in arable fields and restored field margins, as
           related to management practices and surrounding landscape diversity
    • Authors: Joana Frazão; Ron G.M. de Goede; Lijbert Brussaard; Jack H. Faber; Jeroen C.J. Groot; Mirjam M. Pulleman
      Pages: 1 - 8
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Joana Frazão, Ron G.M. de Goede, Lijbert Brussaard, Jack H. Faber, Jeroen C.J. Groot, Mirjam M. Pulleman
      Agricultural intensification has negative impacts on biodiversity at spatial scales from field to landscape. Earthworms are important for soil functioning, so it is crucial to understand the responses of earthworm communities to agricultural management and land use. We aimed to: 1) investigate whether earthworm communities differed between relatively undisturbed field margins, and highly disturbed arable fields; and 2) quantify how earthworm communities of arable fields and field margins are affected by three environmental filters, i.e. soil properties, management practices, and composition of the surrounding landscape. Earthworms were sampled in 26 arable fields and 15 field margins, across a polder area in The Netherlands. While earthworm density, total biomass and species richness did not differ significantly among arable fields and field margins, rarefied earthworm species richness and community composition did. The three environmental filters affected earthworm communities of arable fields and field margins differently. In arable fields, earthworm communities were explained by arable management only (26%). In contrast, all three filters contributed significantly to the variation in earthworm communities of field margins, where management practices explained a larger part of the variation (18%) than the surrounding landscape (11%) and soil properties (10%). Our results suggest that soil properties and surrounding landscape can affect earthworm communities of field margins. However, in the arable fields, where more diverse lumbricid communities are desirable to improve soil functions, such influences are negated by the impact of management at field scale. We demonstrated that field margins enhance earthworm biodiversity in arable landscapes, but surrounding landscape and field margins had limited impact on earthworm communities in arable fields. Decision-making and research should focus on less intensive management options for arable fields to stimulate earthworms and earthworm-mediated soil functions.

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.014
      Issue No: Vol. 248 (2017)
  • Converting bahiagrass pasture land to elephantgrass bioenergy production
           enhances biomass yield and water quality
    • Authors: Joel Reyes-Cabrera; John. E. Erickson; Ramon G. Leon; Maria L. Silveira; Diane L. Rowland; Lynn E. Sollenberger; Kelly T. Morgan
      Pages: 20 - 28
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Joel Reyes-Cabrera, John. E. Erickson, Ramon G. Leon, Maria L. Silveira, Diane L. Rowland, Lynn E. Sollenberger, Kelly T. Morgan
      Changing pasture land to the production of bioenergy crops will affect regional water dynamics. Returning by-products of industrial conversion of bioenergy crops like fermentation residual or biochar back to the field could be used to improve sustainable nutrient management, but could also impact water quantity and quality in ways that are poorly understood. The objective of this study was to assess the effects of land-use conversion from low-input bahiagrass (Paspalum notatum Flüggé) pastures to elephantgrass [Pennisetum purpureum (L.) Schum.] for bioenergy production under different nutrient management practices on biomass yield, crop water dynamics and nitrate-nitrogen (NO3-N) leaching during growing and dormant seasons. Treatments evaluated were 1) bahiagrass+50kgNha−1; 2) elephantgrass+50kgNha−1; 3) elephantgrass+50kgNha−1 +fermentation residual; 4) elephantgrass+50kgNha−1 +biochar; and 5) elephantgrass+250kgNha−1. Data were collected on crop evapotranspiration (ET), water use efficiency, drainage, NO3-N leaching, and aboveground dry matter accumulation. Dry matter yield of elephantgrass was 4- to 7-fold greater than bahiagrass after the first growing season, but was similar among elephantgrass treatments. Elephantgrass produced with no residual amendments reduced drainage (approx. 43% across all growing seasons) compared to bahiagrass, and this reduction was exacerbated in the residual treatments. Reduced drainage was associated with increased ET. Elephantgrass, regardless of treatment, reduced the amount of NO3-N lost through drainage compared to bahiagrass. Therefore, replacing bahiagrass with elephantgrass will increase cropping system water use and diminish the rate of groundwater replenishment during the growing season, which could have detrimental effects for other ecosystem processes that rely on this water resource. However, elephantgrass increased the efficiency with which water was used to produce biomass and reduced NO3-N leaching to groundwater.

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.021
      Issue No: Vol. 248 (2017)
  • Effects of precipitation changes on aboveground net primary production and
           soil respiration in a switchgrass field
    • Authors: Qi Deng; Sadiye Aras; Chih-Li Yu; E. Kudjo Dzantor; Philip A. Fay; Yiqi Luo; Weijun Shen; Dafeng Hui
      Pages: 29 - 37
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Qi Deng, Sadiye Aras, Chih-Li Yu, E. Kudjo Dzantor, Philip A. Fay, Yiqi Luo, Weijun Shen, Dafeng Hui
      Switchgrass (Panicum virgatum L.) is widely selected as a model feedstock for sustainable replacement of fossil fuels and climate change mitigation. However, how climate changes, such as altered precipitation (PPT), will influence switchgrass growth and soil carbon storage potential have not been well investigated. We conducted a two-year PPT manipulation experiment with five treatments: −50%, −33%, +0%, +33%, and +50% of ambient PPT, in an “Alamo” switchgrass field in Nashville, TN. Switchgrass aboveground net primary production (ANPP), leaf gas exchange, and soil respiration (SR) were determined each growing season. Data collected from this study was then used to test whether switchgrass ANPP responds to PPT changes in a double asymmetry pattern as framed by Knapp et al. (2017), and whether it is held true for other ecosystem processes such as SR. Results showed that the wet (+33%, and +50%) treatments had little effects on ANPP and leaf gas exchange compared to the ambient precipitation treatment, regardless of fertilization or not. The −33% treatment did not change ANPP and leaf photosynthesis, but significantly decreased transpiration and enhanced water use efficiency (WUE). Only the −50% treatment significantly decreased ANPP and LAI, without changing leaf photosynthesis. SR generally decreased under the drought treatments and increased under the wet treatments, while there was no significant difference between the two drought treatments or between the two wet treatments. Our results demonstrate that switchgrass ANPP responded in a single negative asymmetry model to PPT changes probably due to relative high PPT in the region. However, even in such a mesic ecosystem, SR responded strongly to PPT changes in an “S” curve model, suggesting that future climate changes may have greater but more complex effects on switchgrass belowground than aboveground processes. The contrasting models for switchgrass ANPP and SR in response to PPT indicate that extreme wet or dry PPT conditions may shift ecosystem from carbon accumulation toward debt, and in turn provide government and policy makers with useful information for sustainable management of switchgrass.

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.023
      Issue No: Vol. 248 (2017)
  • The sequestration and turnover of soil organic carbon in subtropical
           leucaena-grass pastures
    • Authors: Kathryn A. Conrad; Ram C. Dalal; Scott A. Dalzell; Diane E. Allen; Neal W. Menzies
      Pages: 38 - 47
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Kathryn A. Conrad, Ram C. Dalal, Scott A. Dalzell, Diane E. Allen, Neal W. Menzies
      The sequestration of soil organic carbon (SOC) in agricultural systems has the potential to partially mitigate climate change by removing carbon dioxide (CO2) from the atmosphere. Furthermore, incorporating forage legumes into a grazing system may aid in C storage, as mature unfertilized pasture soils are typically nitrogen (N) limited. Leucaena leucocephala, a leguminous shrub, is often incorporated into grazing systems to provide a source of protein for cattle production. Additionally, leucaena improves the N fertility of grazing lands. Despite this, there is limited research on the C and N dynamics beneath leucaena-grass pastures, particularly at depth in the soil profile (1m). We assessed the potential of leucaena to sequester SOC by estimating the origin (C3 or C4), quantity and vertical distribution of SOC stocks. A chronosequence of seasonally grazed leucaena stands (0, 9, 22, 34, 40 years) were sampled for organic C and natural δ13C abundance. Pasture type affected SOC stocks within the upper 0.2m (grass<leucaena mid-row=leucaena row). SOC stocks were also affected by leucaena stand age. In the 0–0.3m zone, SOC increased by 17–30% over 40 years, equating to a sequestration rate of 280kgha−1 year−1. Soil δ13C values were depleted below the C3 leucaena rows (−16‰) compared to the C4 grass pasture (−13‰). However, the majority of SOC displayed a C4 C signature. Hence, SOC sequestration primarily occurred due to N accretion by leucaena (36kgNha−1 year−1) contributing to the increased C4 grass productivity, humus formation and slowed SOC decomposition. Therefore, there is a need to maintain soil fertility in grazed pastures to ensure SOC stocks are accreted and conserved.

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.020
      Issue No: Vol. 248 (2017)
  • Including cover crops during fallow periods for increasing ecosystem
           services: Is it possible in croplands of Southern South America'
    • Authors: Priscila Pinto; María E. Fernández Long; Gervasio Piñeiro
      Pages: 48 - 57
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Priscila Pinto, María E. Fernández Long, Gervasio Piñeiro
      The integration of cover crops (CC) into annual crop rotations improves the provision of multiple ecosystem services in time and represents an alternative paradigm to achieve sustainability goals. In spite of the benefits that several authors have exposed, CC are seldom included in rotations because their water consumption could affect cash crops development. We evaluated the possibility of including CC in the agricultural area of Rio de la Plata grasslands and identified its optimal duration depending on both environmental conditions and crop rotations. Fallow areas were located based on NDVI time series derived from MODIS satellite images and the influence of CC on the subsequent cash crop was evaluated based on modeled changes in soil water contents at the sowing date of the cash crop. Our land use classifications revealed that single crop rotations, mostly summer crops with winter fallow periods, occupy a large proportion (89%) of the agricultural portion of the Rio de la Plata grasslands studied. In most of the region, sowing CC of 3 to 5 months of length during fallow periods had little impact on soil water contents at the sowing date of the following cash crop. As expected, the optimal CC duration in the different sub-regions increased with the average rainfall occurred during the fallow period. The possibility of sowing CC without affecting cash crops yields opens the opportunity for intensifying crop sequences in the region, oriented to mitigate environmental concerns raised by monocultures and agricultural simplification.
      Graphical abstract image

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.028
      Issue No: Vol. 248 (2017)
  • Farm-scale greenhouse gas balances, hotspots and uncertainties in
           smallholder crop-livestock systems in Central Kenya
    • Authors: Daniel Ortiz-Gonzalo; Philippe Vaast; Myles Oelofse; Andreas de Neergaard; Alain Albrecht; Todd S. Rosenstock
      Pages: 58 - 70
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Daniel Ortiz-Gonzalo, Philippe Vaast, Myles Oelofse, Andreas de Neergaard, Alain Albrecht, Todd S. Rosenstock
      Climate-smart approaches have gained momentum in tropical, agricultural development. However, to date, few studies have examined whole-farm greenhouse gas (GHG) balances in smallholder crop-livestock systems. This study aimed to quantify GHG balances at farm-scale, identify GHG hotspots and assess mitigation options in coffee-dairy farms undergoing agricultural intensification in Central Kenya. In recent decades, decreasing farm size has forced the shift from extensive practices to zero-grazing systems and higher nitrogen (N) inputs. We hypothesised that different farm strategies and intensification levels determine the farm’s GHG balance. A farm typology was constructed through principal component analysis (PCA) and hierarchical clustering from 125 farms surveyed. Four farm types were identified ranging relatively from small to large farms, low to high livestock intensities, and low to high N input rates. Whole-farm GHG balances were estimated using an adapted version of the Cool Farm Tool (CFT). Farms were found to be net sources of GHG, averaging from 4.5tCO2 eqha−1 yr−1 in less intensive farms to 12.5tCO2 eqha−1 yr−1 in high intensive farms. Within the farm GHG hotspots identified, methane (CH4) from enteric fermentation processes accounted for 26–39% of total farm GHG emissions; nitrous oxide (N2O) and CH4 from manure management systems (MMS) for 26–38%; soil background and fertilizer induced N2O emissions for 24–29%; off-farm production of feeds and agrochemicals for 10–22%; and crop residue management (CRM) for the remaining 1–3%. Within the mitigation practices assessed, zero-grazing stalls already lowered the livestock maintenance energy requirements, reducing enteric fermentation emissions. Stall-feeding, however, brings the necessity-opportunity to manage the manure and our results showed that MMS can be a determining factor in the GHG balance. Increasing the frequency of manure collection from stalls in favour of solid storage systems can reduce N2O emissions by up to 75%. Furthermore, dry manure storage reduced the CH4 emissions of liquid slurry systems by more than 70%. Further benefits in terms of carbon (C) sequestration were identified along farm types from manure and crop residues applications in soils (with averages of −1.3 to −2.3tCO2 eqha−1 yr−1) and biomass growth in agroforestry systems (−1.2 to −2tCO2 eqha−1 yr−1). Together, soils and woody biomass offset 25–36% of farm emissions. We conclude that reduced farm size and increased livestock density lead to higher emissions per unit area, though this increase is smoothed by larger negative fluxes in soils (by higher C inputs) and woody biomass (by higher tree densities) until a steady state is reached. Average yield-scaled emissions, or product carbon footprints (CFs), resulted in 1.08kg CO2 eq kg coffee berry−1, 0.64kg CO2 eq kg maize−1 and 1.05kg CO2 eq kg milk−1 on average. CFs did not always differ between farm types and intensification levels, meaning that increases in productivity were not higher than increases in GHG fluxes from intensification. This may be due to: 1) increases in productivity are the result of more processes other than N inputs; and/or 2) emissions from N inputs are overestimated by EFs and GHG calculators. Smallholders may benefit in the near future from climate initiatives and further field characterisation, models calibration and monitoring are required to overcome critical levels of uncertainty and provide more accurate estimations of GHG balances at farm-scale.
      Graphical abstract image

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.06.002
      Issue No: Vol. 248 (2017)
  • Effects of landscape and habitat quality on Orthoptera assemblages of
           pre-alpine calcareous grasslands
    • Authors: Franz Löffler; Thomas Fartmann
      Pages: 71 - 81
      Abstract: Publication date: 1 October 2017
      Source:Agriculture, Ecosystems & Environment, Volume 248
      Author(s): Franz Löffler, Thomas Fartmann
      Due to the transition from traditional land use to modern agriculture throughout Europe, semi-natural grasslands are subject to severe environmental changes. Both agricultural intensification and abandonment have caused degradation, loss and fragmentation of semi-natural grasslands with adverse effects on biodiversity. We analysed the effects of landscape and habitat quality on Orthoptera in pre-alpine calcareous grasslands of the Northern Limestone Alps. At the landscape level, we focused on the effects of functional connectivity, patch size and habitat heterogeneity on Orthoptera species richness of 13 randomly selected grassland patches. At the habitat level, we studied the effects of land use on vegetation structure and microclimate as well as on Orthoptera species richness and abundance on 50 randomly chosen plots within these patches. At the landscape level, the number of Orthoptera species in well-connected pre-alpine calcareous grasslands increased with habitat heterogeneity, which was inter-related with patch size. Functional connectivity, however, had no effect on species richness. At the habitat level, species richness and abundance of Orthoptera were driven by land use together with vegetation structure and microclimate. In general, the explanatory power of our abundance models was at least twice as high as those of the species richness models. Based on the results of our study, conservation management of grassland Orthoptera should primarily focus on improving habitat heterogeneity and habitat quality within patches.

      PubDate: 2017-08-03T02:34:30Z
      DOI: 10.1016/j.agee.2017.07.029
      Issue No: Vol. 248 (2017)
  • Impact of fertilization regimes on diazotroph community compositions and
           N2-fixation activity in paddy soil
    • Authors: Yafang Tang; Miaomiao Zhang; Anlei Chen; Wenzhao Zhang; Wenxue Wei; Rong Sheng
      Pages: 1 - 8
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Yafang Tang, Miaomiao Zhang, Anlei Chen, Wenzhao Zhang, Wenxue Wei, Rong Sheng
      Nutrient status in soil is crucial for the growth and activity of resident microorganisms, which in turn regulate nitrogen transformation in the terrestrial biosphere. Biological nitrogen fixation (BNF) is an important N input in agricultural ecosystems, but the influence of fertilization on the structural and functional behavior of diazotrophs is not clear. In this study, we assessed the nutrient limitations on the abundance and N2-fixation activity of diazotrophs in a long term (20 years) fertilization experiment. Although both phosphorus (P) deficiency and potassium (K) deficiency resulted in significant decreases in nifH gene expression and N2-fixation activity, P deficiency exhibited more restrictive effects. Assessments of community structures based upon transcripts also indicated that the active diazotroph populations were more sensitive to P deficiency than K deficiency, and some diazotroph groups were detected in the P deficiency treatment. Long-term rice straw addition significantly increased diazotroph abundance, but in contrast, sharply reduced nifH gene expression and N2-fixation activity. The close relationship between N2-fixation activity and nifH gene expression rather than its copy number suggests that the nifH gene transcript level is a suitable indicator for predicting the N2-fixation activity of N2-fixing microorganisms in paddy soil of various fertility status.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.009
      Issue No: Vol. 247 (2017)
  • Impacts of incorporating dominant crop rotation patterns as primary land
           use change on hydrologic model performance
    • Authors: Jungang Gao; Aleksey Y. Sheshukov; Haw Yen; Jude H. Kastens; Dana L. Peterson
      Pages: 33 - 42
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Jungang Gao, Aleksey Y. Sheshukov, Haw Yen, Jude H. Kastens, Dana L. Peterson
      Crop rotation is a commonly used management practice in the central U.S. whereby different agricultural crops are grown on a farm field in successive years to help maintain the productive capacity of the soil. Understanding hydrologic responses to crop rotation is critical for developing appropriate crop rotation strategies for sustainable water resources management. These responses are not well understood due to limited availability of multi-year, crop-specific land use-land cover data. The study focuses on the Smoky Hill River watershed in west-central Kansas, a typical agro-ecosystem watershed in the Central Great Plains of the U.S. A multi-year land use dataset developed for the state of Kansas was used to identify 3-year crop rotation patterns in the watershed for three different periods (2006–08, 2008–10, 2010–12). Out of 276 unique rotations, 21 rotations were found to be dominant, with rotation patterns of grain sorghum-fallow-winter wheat (G-F-W), winter wheat-winter wheat-fallow (W-W-F), and continuous winter wheat (W-W-W) occupying more than 81% of the cropland in each rotation period. From 2006 to 2012, the coverage of grain sorghum increased by 26% and corn by 305%, while winter wheat decreased by 20%. Three 11-year simulation scenarios based on three 3-year crop rotation patterns were implemented in the SWAT model and separately calibrated for streamflow at two gauge sites. The SWAT model produced good calibration statistics for the periods corresponding to the applied crop rotations, while the statistics tended to decrease for other periods, with Nash-Sutcliffe Efficiency coefficient becoming unsatisfactory for periods of six to eight years outside of the calibration period. Applying a different number of dominant crop rotations to the SWAT model, it was found that the number can be reduced down to the five most dominant without significant loss in model performance. While the optimum number of crop rotations must be evaluated for each agricultural watershed, this finding provides valuable information for watershed model development and calibration, which can help to avoid issues of over-parameterization and equifinality.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.019
      Issue No: Vol. 247 (2017)
  • Strategies for the use of urease and nitrification inhibitors with urea:
           Impact on N2O and NH3 emissions, fertilizer-15N recovery and maize yield
           in a tropical soil
    • Authors: M.R. Martins; S.A.C. Sant’Anna; M. Zaman; R.C. Santos; R.C. Monteiro; B.J.R. Alves; C.P. Jantalia; R.M. Boddey; S. Urquiaga
      Pages: 54 - 62
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): M.R. Martins, S.A.C. Sant’Anna, M. Zaman, R.C. Santos, R.C. Monteiro, B.J.R. Alves, C.P. Jantalia, R.M. Boddey, S. Urquiaga
      Maize production accounts for the largest proportion of synthetic fertilizer-N used in Brazil, with most of it being urea. The use of this fertilizer raises significant agronomic and environmental concerns due to an elevated risk of gaseous N losses, resulting in low fertilizer-N recovery by plants and increasing anthropogenic greenhouse gas (GHG) emissions. In a field trial on a tropical Acrisol, we quantified the N losses caused by the gaseous emissions of NH3 and N2O and the grain yield and recovery of 15N-fertilizer by maize plants treated with urea with added nitrapyrin or N-(n-butyl) thiophosphoric triamide (NBPT). Under conditions favorable for gaseous N loss from fertilizers, nitrapyrin reduced the cumulative N2O emission by 49% over a period of 30days after the subsurface application of side-banded urea (50kgNha−1) during maize sowing. The use of NBPT delayed urea hydrolysis and reduced the NH3 volatilization by 35%, which represents a significant reduction in indirect N2O emission due to subsequent atmospheric deposition. The use of nitrapyrin during sowing and NBPT during the V5 stage of maize growth enhanced urea-15N recovery by 53% and increased maize grain yield by 1.5tha−1 compared to regular urea. Our results indicate that considering the main potential N losses according to timing and placement of fertilizer, the specific use of inhibitors represents an efficient strategy to improve the urea-N recovery and the maize grain yield. The use of nitrification inhibitors can play an effective role in mitigating N2O emissions from typical N fertilization practices in maize-producing areas in Brazil. This study also indicates the need for considering indirect emissions in the overall balance of N2O emissions derived from enhanced-efficiency fertilizers.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.021
      Issue No: Vol. 247 (2017)
  • Soil carbon and nitrogen dynamics as affected by land use change and
           successive nitrogen fertilization of sugarcane
    • Authors: Thales Meinl Schmiedt Sattolo; Eduardo Mariano; Beatriz Nastaro Boschiero; Rafael Otto
      Pages: 63 - 74
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Thales Meinl Schmiedt Sattolo, Eduardo Mariano, Beatriz Nastaro Boschiero, Rafael Otto
      The land use change (LUC) and application of N fertilizers have potential to affect soil C and N dynamics and long–term C and N stocks. We aimed to evaluate the effects of the LUC from native vegetation (seasonal semideciduous forest) to sugarcane (Saccharum spp.) cultivation under successive annual N fertilizer applications on chemical and microbiological attributes of sugarcane–cropped soils. Two field trials were performed during three (Site 1) or four years (Site 2) in southeastern Brazil. Soil sampling was carried out in the following N treatments applied to the crop: control (N–unfertilized plots), organomineral fertilizer (100kgha−1 yr−1 N), and synthetic fertilizer (100 and 200kgha−1 yr−1 N). Soil samples from native vegetation located near each site were also taken, to serve as reference for studying LUC. For Site 1, successive application of N fertilizers on sugarcane managed under green cane trash blanketing system maintained the C and N dynamics and stocks in soil to conditions similar to those found before LUC. At Site 2, however, modifications in soil attributes caused by LUC were more impacting than the N fertilization management. Compared to synthetic N fertilizers, successive application of organomineral fertilizer did not improve the soil microbiological attributes as well as organic C and total N stocks. Lastly, successive high N input (200kgha−1 yr−1, via synthetic fertilizer) promoted accumulation of mineral N deep in the soil profile, thus increasing potential losses through NO3 − leaching.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.005
      Issue No: Vol. 247 (2017)
  • The effect of irrigation on cadmium, uranium, and phosphorus contents in
           agricultural soils
    • Authors: Mahdiyeh Salmanzadeh; Louis A. Schipper; Megan R. Balks; Adam Hartland; Paul L. Mudge; Ray Littler
      Pages: 84 - 90
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Mahdiyeh Salmanzadeh, Louis A. Schipper, Megan R. Balks, Adam Hartland, Paul L. Mudge, Ray Littler
      Cadmium (Cd) is a toxic metal which has accumulated in New Zealand agricultural soils due to phosphate fertilizer application. Understanding the contribution of plant uptake or leaching of Cd to observed Cd losses from soil is important. The concentration and distribution of Cd in irrigated and unirrigated soils with the same phosphate fertilizer history were investigated. Twenty-two pairs of soil samples from four depths (0–0.1, 0.1–0.2, 0.2–0.3 and 0.3–0.4m) were taken from irrigated and unirrigated areas in the same field on dairy farms in three regions of New Zealand. The mean concentration of Cd at depths of 0–0.1m and 0.1–0.2m, as well as the cumulative masses of Cd (0–0.2, 0–0.3 and 0–0.4m) in unirrigated soils were significantly higher (P <0.05) than in irrigated soils. The concentration of phosphorus (P) at all depths (except for 0.2–0.3m), as well as the cumulative mass of P in all depths of unirrigated soils, was also significantly higher (P <0.05) than irrigated soils. However, no significant difference was detected in the concentrations of uranium (U) between irrigated and unirrigated soils. Irrigation induced a ∼7% Cd loss from topsoil (0–0.1m), with the average rate of Cd loss from the top 0.1m (due to irrigation) being 2.3gha−1 yr−1. This study therefore confirms that irrigation can enhance Cd mobilization, however Cd is mainly adsorbed to the surface soil.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.028
      Issue No: Vol. 247 (2017)
  • Effects of the conversion of intensive grasslands into Christmas tree
           plantations on bird assemblages
    • Authors: Robin Gailly; Jean-Yves Paquet; Nicolas Titeux; Hugues Claessens; Marc Dufrêne
      Pages: 91 - 97
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Robin Gailly, Jean-Yves Paquet, Nicolas Titeux, Hugues Claessens, Marc Dufrêne
      Over the last decade, the conversion of annual-rotation based crops or grassland areas into non-food perennial crops has been increasingly prevalent in European farming systems. This shift is associated with major changes in management practices and has created new environmental conditions and resources for wildlife. Impacts on birds have been examined for bioenergy agricultural systems, such as miscanthus plantations and short-rotation willow coppice. However, they remain largely unknown for Christmas tree plantations (CTPs) that have recently increased considerably in some European countries. We examined the extent to which CTPs alter bird species assemblages in the farmland areas of southern Belgium, where they mainly replace intensive grassland. The abundance of birds was recorded during the breeding season in randomly selected sites located in grassland and in CTP. Results show that introduction of CTP into landscapes dominated by grassland with low hedge densities locally increases bird species richness and abundance without leading to biotic homogenization. Differences in species richness and abundance between grassland and CTP decrease with increasing hedge densities. A community analysis indicates that the plantation of Christmas trees enriches the bird assemblage of intensive grassland areas. In intensive grassland with few hedges, small-size CTPs could constitute an option to increase structural heterogeneity and provide new potential breeding conditions for some farmland birds. However, questions remain about the genuine quality of the resources available in CTP and further research is needed to examine the breeding success and survival of birds that settle in this type of habitat.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.029
      Issue No: Vol. 247 (2017)
  • Trees increase soil organic carbon and nutrient availability in temperate
           agroforestry systems
    • Authors: P. Pardon; B. Reubens; D. Reheul; J. Mertens; P. De Frenne; T. Coussement; P. Janssens; K. Verheyen
      Pages: 98 - 111
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): P. Pardon, B. Reubens, D. Reheul, J. Mertens, P. De Frenne, T. Coussement, P. Janssens, K. Verheyen
      Agroforestry systems (AFS) have a large potential to deliver a wide range of ecosystem services (ES). In field and crop management, changes to factors such as regulatory ES delivery are rarely taken into account, in part due to the paucity of detailed quantification of how trees affect biophysical field characteristics. This is especially true for arable systems in temperate climates. We have therefore assessed the influence of rows of trees of varying size on the prevailing soil characteristics in arable AFS. Spatial variability of soil organic carbon, acidity and nutrient status (N, P, K, Ca, Mg and Na) of the plough layer were analysed on a set of 17 arable agroforestry fields comprising 6 young (<5years) alley cropping fields and 11 fields bordered by a row of trees of moderate to older age (15–47 years) in Belgium. Significantly higher soil organic carbon and soil nutrient concentrations of N, P, K, Mg and Na were observed in the vicinity of trees in field boundaries, most likely resulting from the input of tree litter and nutrient-enriched throughfall water (forK and Na). Observed increases were strongly related to the distance from the tree row, resulting in a gradual change in soil conditions up to at least 30m into the field. No significant effects of distance from the tree rows on soil characteristics were found in the young alley cropping fields. These results highlight the potential of middle-aged to mature tree rows to increase soil organic carbon stocks and nutrient availability for the agricultural crop in AFS.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.018
      Issue No: Vol. 247 (2017)
  • Prior rainfall pattern determines response of net ecosystem carbon
           exchange to a large rainfall event in a semi-arid woodland
    • Authors: Qiaoqi Sun; Wayne S. Meyer; Georgia R. Koerber; Petra Marschner
      Pages: 112 - 119
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Qiaoqi Sun, Wayne S. Meyer, Georgia R. Koerber, Petra Marschner
      Semi-arid climate is characterized by long dry periods which are interrupted by rainfall events differing in magnitude. The effect of these rainfall events on ecosystem carbon fluxes has been studied in semi-arid grass and shrublands, but data for woodlands is lacking. In this study net ecosystem productivity (NEP), partitioned ecosystem respiration (Reco) and gross primary productivity (GPP) in a semi-arid eucalyptus woodland were measured using eddy covariance data. Four natural large rainfall events with similar magnitude (35–60mm), but contrasting previous rainfall patterns (several moderate rainfall events vs. limited or no rainfall) were chosen. NEP, Reco and GPP rates 28days prior to and 35days after the three central rainfall events were used. Prior rainfall patterns influenced ecosystem carbon fluxes after the central rainfall event. GPP rates were not affected by the four rainfall events. After four weeks with several medium to large rainfall events, the central rainfall event had little effect on Reco. In contrast, a large rainfall event following four weeks with very little rainfall induced an increase in Reco for about three weeks and thus a decrease in NEP. The strong increase in Reco after the central rainfall event can, at least partly, be explained by an increase in soil respiration upon rewetting. A water addition experiment (30mm rainfall simulation) conducted in the field following a long dry period (only 4.8mm rainfall input in 45days) showed that heterotrophic soil respiration usually decreases rapidly after rewetting. In the sandy soil of the study area, the top 0–5cm dry within a few days after rainfall, but at 10cm depth the soil remained moist for several weeks after the large rainfall event that followed a long dry period. Therefore, sustained higher Reco following the large rainfall event could be due to respiration of roots in the moist deeper soil layers. We conclude that the previous rainfall should be considered when interpreting the response of ecosystem C fluxes to rainfall events which could alter ecosystem carbon balance and may potentially affect seasonal or inter-annual variability of ecosystem carbon uptake.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.032
      Issue No: Vol. 247 (2017)
  • Effects of “Grain for Green” program on soil hydrologic functions in
           karst landscapes, southwestern China
    • Authors: Jiao Yang; Xianli Xu; Meixian Liu; Chaohao Xu; Yaohua Zhang; Wei Luo; Rongfei Zhang; Xuezhang Li; Gerard Kiely; Kelin Wang
      Pages: 120 - 129
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Jiao Yang, Xianli Xu, Meixian Liu, Chaohao Xu, Yaohua Zhang, Wei Luo, Rongfei Zhang, Xuezhang Li, Gerard Kiely, Kelin Wang
      Soil hydrologic functions are important for karst landscapes where soil water loss is significant. The largest global ecological restoration engineering project, namely the “Grain for Green” program, is being implemented since 2000 in karst landscapes across southwestern China. However, its effects on soil hydrologic functions are still unknown. Using data acquired in field investigations and a generalized linear model (GLM), this study examines the effects of different vegetation restoration types on soil field saturated-hydraulic conductivity (Kfs ) in karst landscapes of southwest China. The results indicate that the Kfs of artificial grassland (napiergrass) was higher than in other vegetation restoration types (zenia insignis, toona sinensis, orchard, and natural restoration shrubland) and cropland at both the surface and 10cm depths. The Kfs of vegetation restoration lands was lower than that of Mulun nature reserve (primary forest) at both the surface and 30cm depths. We found significant differences of Kfs in different depths of vegetation restoration lands but not significant for primary forest. The GLM model explains 64.75% of the total variation in Kfs . Among the input variables, vegetation type explained the largest proportion (11.29%) of the variation, followed by bulk density (BD), soil organic carbon, and BD and vegetation type interactions. The factors above were significantly related to Kfs . This study suggests that the implementation of different vegetation restoration types can alter soil hydrologic functions and provides useful knowledge for ecological restoration practices and management in karst landscapes.

      PubDate: 2017-07-03T02:07:57Z
      DOI: 10.1016/j.agee.2017.06.025
      Issue No: Vol. 247 (2017)
  • Neglected pollinators: Can enhanced pollination services improve cocoa
           yields' A review
    • Authors: Manuel Toledo-Hernández; Thomas C. Wanger; Teja Tscharntke
      Pages: 137 - 148
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Manuel Toledo-Hernández, Thomas C. Wanger, Teja Tscharntke
      The negative effects of climate change on cocoa production are often enhanced through agricultural intensification, while research institutions and enterprises try to minimize yield gaps with production strategies mitigating climate risk. Ecological intensification is such a production strategy, whereby yield increase is promoted through reduced agrochemical inputs and increased regulating ecosystem services such as pollination. However, we still know little about cocoa pollination ecology and services, although they appear to be key to understand yield functions. Here, we provide an extensive literature review on cocoa pollination focusing on three main aspects: non-plant (external) and plant regulated (internal) factors affecting pollination, pollinator agents, and ecological intensification management for enhancing pollination success and yield. Pollination services by many arthropod groups such as ants, bees, and parasitic wasps, and not only ceratopogonids, may be a way to increase cocoa productivity and secure smallholders income, but their role is unknown. Several environmental and socioeconomic factors can blur potential pollination benefits. Current knowledge gaps preclude our understanding of how to (i) identify the major pollinator species, (ii) disentangle the direct or indirect role of ants in pollination, (iii) design effective habitat improvements for pollination (by litter and shade management), and (iv) quantify the yield gaps due to pollination limitation. Optimizing cocoa pollination alone appears to be a powerful ecological tool to increase the yield of smallholders, but experimental research is required to validate these results in a realistic setting. In general, industry, governments and smallholders need to develop more joined efforts to ecological production strategies. In particular, farm-base management innovations based on robust scientific evidence must be designed to meet the increasing demand for chocolate and to mitigate cocoa yield gaps. This review suggests that diversified systems and associated ecosystem services, such as pollination, can help to achieve such goals.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.05.021
      Issue No: Vol. 247 (2017)
  • Beneficial traits of bacterial endophytes belonging to the core
           communities of the tomato root microbiome
    • Authors: Baoyu Tian; Cuijuan Zhang; Yuan Ye; Jiaming Wen; Yimin Wu; Hongzhu Wang; Huimin Li; Shixian Cai; Weiting Cai; Zhiqiang Cheng; Shaonan Lei; Rongqin Ma; Chaojun Lu; Yi Cao; Xiaohong Xu; Keqin Zhang
      Pages: 149 - 156
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Baoyu Tian, Cuijuan Zhang, Yuan Ye, Jiaming Wen, Yimin Wu, Hongzhu Wang, Huimin Li, Shixian Cai, Weiting Cai, Zhiqiang Cheng, Shaonan Lei, Rongqin Ma, Chaojun Lu, Yi Cao, Xiaohong Xu, Keqin Zhang
      Extensive research has been done to assess the potential of endophytes as inoculants to promote plant growth and as biocontrol agents. However, little work has been done to determine the key endophytes and their associated functions that benefit or harm plant growth or protect the host from pathogens at the community level. In this study, we attempted to identify plant growth-promoting endophytes within the bacterial groups identified as part of the core tomato root microbiome. In total, 49 bacterial endophytic strains, identified as members of the phyla of Firmicutes and Proteobacteria, were picked and isolated from tomato roots on selected media. A phylogenetic analysis was performed using the 16S rRNA gene sequences that were obtained from the isolated bacterial endophytes and the core OTUs of the previously published tomato root microbiome. The results indicated that the isolates clustered into groups of the orders Pseudomonadales, Enterobacteriales, Rhizobiales, Burkholderiales, and Xanthomonadales, representing the majority of the Proteobacterial groups of tomato root endophytes, in addition to the phylum Firmicutes. In vitro bioassays showed that most strains (31 of the 49 isolated endophytic strains) showed antagonistic activity against the tested microbial targets, including Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Aspergillus niger. Most of the endophytic isolates with antimicrobial activities were from the genera Bacillus and Pseudomonas. However, few of the identified active strains clustered with the core endophytic groups. In experiments to assess the ability of endophytes to promote the growth of wheat plants in vivo, almost all the isolated tomato root endophytic strains demonstrated an ability to promote plant growth. Four strains were shown to produce IAA when grown in medium containing L-tryptophan. The IAA-producing Pseudomonas spp. closely clustered with the most abundant Pseudomonadales OTU, which harbored an intact IAA synthesis pathway using the precursor tryptophan. Eighteen identified nitrogen-fixing endophytes were primarily Bacillus and Rhizobium species. The results suggested that in tomato root endophytes, most of the tested plant host-benefiting traits were derived from bacteria of three genera, Pseudomonas, Bacillus and Rhizobium. Bacillus strains have great taxonomic and functional potential to explore as biological agents that contribute diverse nutrient acquisition and growth promotion activities to their hosts. As one of the most predominant groups in the healthy tomato root endophytic microbiome, the majority of Pseudomonas spp. showed the most promising potential in promoting plant growth, while other species demonstrated their ability as biological control agents, especially for the fungal targets.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.041
      Issue No: Vol. 247 (2017)
  • Coupling sugarcane yield to soil nematodes: Implications from different
           fertilization regimes and growth stages
    • Authors: Fengge Zhang; Chao Gao; Jichen Wang; Yinglin Lu; Zongzhuan Shen; Ting Liu; Diwen Chen; Wei Ran; Qirong Shen
      Pages: 157 - 165
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Fengge Zhang, Chao Gao, Jichen Wang, Yinglin Lu, Zongzhuan Shen, Ting Liu, Diwen Chen, Wei Ran, Qirong Shen
      Soil nematode communities provide important information for soil food web structure and function. Our study focused on the impacts of different fertilization regimes on sugarcane growth, while primarily considering their effects on soil nematode responses during different growth stages. The sugarcane yields were significantly increased in plots fertilized with functional biofertilizers (BIOs) compared with plots that received chemical fertilizers. Moreover, the BIO applications significantly (P< 0.01) decreased the relative abundance of plant parasite while significantly (P< 0.01) increased the relative abundance of beneficial nematodes: Cephalobus, Cervidellus, Acrobeles, Caenorhabditis in the group of bacteriores and Ditylenchus, Tylencholaimus in the group of fungivores. Nonmetric multidimensional scaling (NMDS) revealed that soil nematode communities were primarily separated by sampling time. A network analysis showed that BIO applications led to more simplified soil nematode community, which was possibly linked with the increased bacterivore abundance and improved soil fertility. The effects of fertilization regimes were significant (P< 0.05) and accounted for 3.35% of the total variation in soil nematode communities. Soil properties (e.g., pH, organic matter, total N, available K and available P) were influenced by the fertilization regimes and different sampling time, which significantly (P< 0.05) explained 14.53% of the soil nematode variation. In conclusion, BIOs applications might facilitate sugarcane yield by increasing the relative abundance of bacterivore while decreasing plant parasites. The changes in soil nematode communities may reflect the soil fertility and health and provide evidence for the benefits of BIO applications for sugarcane crops.
      Graphical abstract image

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.020
      Issue No: Vol. 247 (2017)
  • Effects of field margin type and landscape composition on predatory
           carabids and slugs in wheat fields
    • Authors: Moritz S. Fusser; Sonja C. Pfister; Martin H. Entling; Jens Schirmel
      Pages: 182 - 188
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Moritz S. Fusser, Sonja C. Pfister, Martin H. Entling, Jens Schirmel
      Semi-natural vegetation can affect the colonization of crop fields by invertebrates as a source habitat and by the supplementation of resources. Such effects have been studied at the scale of field margins or at the wider landscape scale, but rarely in combination. Variation in their response to local and landscape factors between crop pests and their natural enemies can have consequences for biological pest control. We studied Arion spp. and Deroceras reticulatum as major slug pests in Europe and beyond, and predatory carabids as their potential antagonists. Predatory carabids and slugs were sampled in 18 wheat fields bordered by different habitat types (arable fields, woody or herbaceous semi-natural vegetation) along a gradient of landscape composition (amount of semi-natural habitats in 1km radius). Species richness of predatory carabids increased with the amount of semi-natural habitats in the landscapes around wheat fields. No effects of landscape composition or adjacent habitat type were observed for predatory carabid activity-density and Deroceras reticulatum. In contrast, Arion spp. had highest numbers in structurally poor landscapes, but only if fields were bordered by woody vegetation. Thus, Arion spp. thrived best in situations where predatory carabid species richness was lowest, indicating that carabids may contribute to the natural control of slug populations. The divergent patterns between carabids and the two slug species demonstrate that more studies of multiple pest species are needed in order to develop comprehensive landscape management strategies for conservation biological control.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.030
      Issue No: Vol. 247 (2017)
  • The effect of paddy drainage water on the survival and growth of unionoid
    • Authors: Mitsunori Nakano
      Pages: 189 - 194
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Mitsunori Nakano
      Agricultural activities have well-known negative and less well-known positive effects on biodiversity and related ecosystems. Knowledge of agricultural methods that positively affect biodiversity should be collected to identify and develop sustainable agricultural practices. The survival and growth of unionoid mussels are likely positively affected by Japanese paddy agriculture. The purpose of this study was to test the hypothesis that paddy drainage water positively affects the survival and growth of two unionoid mussel species (Nodularia douglasiae and Sinanodonta japonica) in ditches. A field experiment was conducted in ditches at two study sites in Japan. Mussel survival rates did not differ between control (into which paddy drainage water did not flow) and drainage (into which paddy drainage water flowed) areas at either site. Mussel growth at Site 1 was not affected by paddy drainage water; however, at Site 2, paddy drainage water positively affected mussel growth. The mean water temperature was 0.2°C higher in the drainage area (21.50°C) than in the control area (21.30°C) at Site 1. At Site 2, the mean water temperature was 3.62°C higher in the drainage area (21.19°C) than in the control area (17.57°C), which may indicate that the drainage area was nearer the optimal water temperature than the control area. Therefore, it is likely that paddy drainage water increased the temperature of the water in the ditch and facilitated mussel growth at Site 2.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.035
      Issue No: Vol. 247 (2017)
  • Efficiency of mechanical seed harvesting for grassland restoration
    • Authors: Michele Scotton; Magdalena Ševčíková
      Pages: 195 - 204
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Michele Scotton, Magdalena Ševčíková
      Maintaining and re-creating species-rich semi-natural grasslands are important issues in current agricultural policy in Europe. The seed that is required for their establishment can be obtained through direct harvesting from semi-natural herbaceous vegetation. To test the efficiency of mechanical seed harvesting on donor Arrhenatherion elatioris grasslands, experiments were performed in northern Italy and eastern Czech Republic. Trials were organized with a randomized block design and involved harvesting as green hay (grass mowing and immediate collection), dry hay (grass mowing and collection after drying on the field), direct combining (grass cutting and threshing at the same combine passage) and seed stripping with pull-type equipment (seed removal without grass cutting with a brush harvester pulled by a tractor). Harvesting was carried out at the time of maximum ripe standing seed yield (SSY) in the first and second regrowth. The harvested materials were analysed for seed number and weight and compared with the SSY. The species composition and phenology were also surveyed. In all methods, the seed mixture obtained contained the species present as seed at harvest time and was correlated with SSY. However, with regard to the seed number collected, the harvesting efficiency changed in relation to species group (grasses or forbs), individual species, seed maturation and regrowth. The most efficient method was harvesting as green hay (efficiency of approximately 71% of SSY and seed mixture composition that was very highly correlated with SSY). The least efficient methods were direct combining (30% of SSY and negative selectivity against light or difficult to detach seeds, producing the highest mean 1000-seeds weight) and harvesting as dry hay (39% of SSY and a high sensitivity to seed maturation level). Seed stripping, operated with downward brush rotation at the leading edge, resulted in an intermediate efficiency (60% of SSY and a seed mixture composition highly correlated with SSY). The harvesting efficiency for seed number was higher at the first regrowth than the second one for both species groups and, especially at the second regrowth, higher for forbs than for grasses. Especially forb harvesting presented a problem with regard to the species number collected. The problem was, not due to harvesting inefficiency but rather for phenological reasons, as several forbs did not produce fertile stems at the first or second regrowth and some other early flowering species had already shed the seed at the harvesting time. These results improve our understanding of factors affecting the efficiency of mechanical harvesting and will help in the preparation of efficient harvesting programs.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.040
      Issue No: Vol. 247 (2017)
  • Effects of land use on trophic states and multi-taxonomic diversity in
           Japanese farm ponds
    • Authors: Nisikawa Usio; Megumi Nakagawa; Takashi Aoki; Shinsuke Higuchi; Yasuro Kadono; Munemitsu Akasaka; Noriko Takamura
      Pages: 205 - 215
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Nisikawa Usio, Megumi Nakagawa, Takashi Aoki, Shinsuke Higuchi, Yasuro Kadono, Munemitsu Akasaka, Noriko Takamura
      Farm ponds are among the most biodiverse anthropogenic freshwater habitats because of their small size, shallow water depth, and aquatic vegetation. Land-use changes, such as converting riparian vegetation to human use or changing the management practices of farm ponds, are assumed to be major factors that change such ecosystems from a clear-water state to a turbid state, leading to deterioration of water quality and biodiversity in such ponds. Using the database of a large-scale pond survey, we evaluated the effects of surrounding land use (landscape factors and modern pond management practices), fish abundance, and other environmental variables on total phosphorus concentration and taxonomic richness patterns of six biological indicators associated with changes in the trophic state. Local- and landscape-level vegetation structure associated with land use and total fish abundance were among the factors influencing the total phosphorus concentration of farm ponds, a main driver of trophic state changes. In addition, a transition from a clear-water state to a turbid state was associated with lower taxonomic richness of aquatic plants, macroinvertebrates, and adult Odonata, and a higher taxonomic richness of phytoplankton and fish. Based on these results, we discuss potential land-use and pond management strategies for conserving and/or restoring the water quality and biodiversity of farm ponds through maintenance of a clear-water state.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.043
      Issue No: Vol. 247 (2017)
  • The role of field margins in supporting wild bees in Mediterranean cereal
           agroecosystems: Which biotic and abiotic factors are important'
    • Authors: Jane Morrison; Jordi Izquierdo; Eva Hernández Plaza; José L. González-Andújar
      Pages: 216 - 224
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Jane Morrison, Jordi Izquierdo, Eva Hernández Plaza, José L. González-Andújar
      Agricultural field margins are often recommended as a cost-effective and efficient method for wild bee conservation, in response to the threat imposed by global pollinator declines as a result of intensive agricultural practices. In this study we compared margin characteristics and wild bee community structure from sites with landscapes of varying agricultural intensity in order to (i) investigate if field margins are valuable for wild bee conservation in all types of landscapes, and (ii) determine which biotic and abiotic margin characteristics best support wild bee abundance and community richness. Margin surveys and wild bee community sampling, comprising pan traps and observations of foraging activity, were carried out over three years at 27 cereal field margins in Catalonia, Spain. Generalized linear models indicated a strong inverse relationship between surrounding landscape diversity and wild bee abundance. The proportion of Halictidae bees (common generalists) increased with decreasing landscape complexity. Floral richness exhibited a positive association with number of foraging bees and morphospecies richness, and was positively correlated with the proportion of shrubs and trees represented in the margins. It was observed that wider margins held a higher proportion of perennial plants and a lower proportion of Halictidae bees. Our study suggests that field margins are more crucial in intensively farmed areas than in heterogeneous landscapes where foraging resources are more abundant. Maintaining wide margins with high flowering plant richness, comprising perennial and shrub species, best supports a dense and diverse bee community. In more diverse landscapes, conservation efforts focused on maintaining the quality of existing natural patches may be most effective.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.047
      Issue No: Vol. 247 (2017)
  • Leaf gas exchange physiology and ion homeostasis of oilseed rape (Brassica
           napus L.) under Mediterranean conditions: Associations with seed yield and
    • Authors: Ioannis T. Tsialtas; Antonios N. Papantoniou; Theodora Matsi; Despo K. Papakosta
      Pages: 225 - 235
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Ioannis T. Tsialtas, Antonios N. Papantoniou, Theodora Matsi, Despo K. Papakosta
      For two growth seasons, four oilseed rape cultivars were tested in two locations under Mediterranean conditions in order to identify leaf physiological [gas exchange and related traits, chlorophyll content (assessed by SPAD), carbon isotope discrimination (Δ), canopy area index] and elemental traits (K, Na, Ca, Mg, their sum and ratios) related to yield and quality. Determinations took place at one vegetative (stem elongation-BBCH 33 stage) and two reproductive stages (50% flowering of the central inflorescence-BBCH 65 stage and end of flowering-BBCH 69 stage). Yield and seed quality were strongly affected by growth season and location; cultivars differed only in quality traits [seed oil concentration (Oil), protein concentration (Prot), glucosinolates in seed meal (Glu), and erucic acid concentration (Eru)]. Exempting SPAD, cultivars did not also differ in physiological traits and this is a possible reason for the lack of significant differentiation in yield. Cultivars that excluded Na more effectively were those with higher SPAD. Across growth seasons and locations, heavy-textured soil, lower temperatures and high precipitation in winter resulted in higher yield and quality. Larger canopy area at BBCH 65 stage led to higher oil yield (OY). In contrast, higher CO2 assimilation rate (at BBCH 65 stage) and SPAD (BBCH 65 and 69 stages) were indicative of stressful conditions (high temperatures and low rainfall) since these two traits were negatively correlated with OY. Moreover, SPAD at BBCH 65 stage was also negatively correlated with Oil. CO2 assimilation rate was strongly controlled by stomata and was almost the half of that previously reported for temperate environments. In accordance with previous works, K was the most effective osmoticum accumulated in oilseed rape leaves under stressful conditions. As a result, leaf K concentration was correlated negatively with Oil and positively with protein concentration; these two quality traits are inversely affected by stressful conditions. Exclusion of Na by K (higher leaf K/Na ratio) at the reproductive stages was related to lower Oil in oilseed rape, which is a salinity tolerant species. A negative correlation found between leaf K and Ca concentrations can be indicative of a partial substitution of K by Ca, in its osmotic role, in oilseed rape grown on calcareous soils under semi-arid conditions.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.036
      Issue No: Vol. 247 (2017)
  • Landscapes, orchards, pesticides–Abundance of beetles (Coleoptera) in
           apple orchards along pesticide toxicity and landscape complexity gradients
    • Authors: Viktor Markó; Zoltán Elek; Anikó Kovács-Hostyánszki; Ádám Kőrösi; László Somay; Rita Földesi; Ákos Varga; Ágnes Iván; András Báldi
      Pages: 246 - 254
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Viktor Markó, Zoltán Elek, Anikó Kovács-Hostyánszki, Ádám Kőrösi, László Somay, Rita Földesi, Ákos Varga, Ágnes Iván, András Báldi
      Landscape composition may influence biodiversity and ecosystem services in agricultural fields. Hitherto, most studies have focused on annual crops and the available information on the impacts of landscape structure in orchards is sparse. In this study, we evaluated the effects of pesticide use as cumulative toxicity on pest and predatory beetle (Coleoptera) assemblages in the canopy of apple orchards surrounded by different proportion of semi-natural vegetation, crop fields and settlements in Hungary. Laboratory data suggest that increasing pesticide toxicity negatively affects predators (coccinellids), but we did not find such a pattern. Supposedly, the effect of pesticides was masked by the continuous recolonisation of orchards from the surrounding landscape. On the contrary, for the less mobile pest species [Anthonomus pomorum, Phyllobius oblongus (Curculionidae)] we did find a decline in abundance along the gradient of increasing pesticide toxicity. Landscape composition around the orchards significantly influenced the abundance of predatory, fungivorous and tourist species, but had no effect on pests. Contrary to expectations, however, semi-natural habitats had a minor effect compared to arable fields, orchards and settlements which habitat types had various effects on the abundance of different coleopteran groups and species. For example, Harmonia axyridis (Coccinellidae) abundance was positively affected by its overwintering sites, i.e. human settlements in spring, semi-natural forests in summer, and arable fields in autumn. The mass immigration of other predatory, fungivorous and tourist species from the surrounding arable fields into the orchards started from July with senescence and harvesting of arable crops. These results suggest that arable fields, other orchards and settlements might be more important sources of colonisation for natural enemies in orchards than certain semi-natural habitats.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.038
      Issue No: Vol. 247 (2017)
  • Using the response-effect trait framework to disentangle the effects of
           agricultural intensification on the provision of ecosystem services by
           Mediterranean arable plants
    • Authors: X.O. Solé-Senan; A. Juárez-Escario; I. Robleño; J.A. Conesa; J. Recasens
      Pages: 255 - 264
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): X.O. Solé-Senan, A. Juárez-Escario, I. Robleño, J.A. Conesa, J. Recasens
      Agricultural intensification structures arable plant communities, including shifts in species assemblages and trait distributions, which affect the provision of ecosystem services. We used a response-effect trait framework to characterize the impact of agricultural intensification on two ecosystem services delivered by arable plants to pollinator and non-pollinator insects and birds. Agricultural intensification was characterized by field position as a gradient of the impact of crop management at field scale and the surrounding landscape heterogeneity, which can be divided into compositional and configurational heterogenenity. Shifts in functional assemblages of response and effect traits were analyzed by multivariate analyses, whereas changes in single trait metrics were analyzed by mixed-model effects. At field scale, we found a trade-off between ruderal and competitive species. The contrasting disturbance regime from boundaries to inner-fields overflows the potential shifts in functional assemblages both for response and effect traits due to the gradient of landscape heterogeneity. Conversely, some response and effect single trait metrics changed along gradients of landscape heterogeneity. We thus propose a response-effect trait framework to capture functional relationships along different trophic levels. Compositional heterogeneity affected traits linked to the provision of suitable habitat for insects and birds, whereas configurational heterogeneity affected traits linked to pollination. Incorporating this framework into decision-making processes may help to focus conservation efforts on maintaining the delivery of ecosystem services.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.07.005
      Issue No: Vol. 247 (2017)
  • Organic farming provides improved management of plant parasitic nematodes
           in maize and bean cropping systems
    • Authors: Janet G. Atandi; Solveig Haukeland; George M. Kariuki; Danny L. Coyne; Edward N. Karanja; Martha W. Musyoka; Komi K.M. Fiaboe; David Bautze; Noah Adamtey
      Pages: 265 - 272
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Janet G. Atandi, Solveig Haukeland, George M. Kariuki, Danny L. Coyne, Edward N. Karanja, Martha W. Musyoka, Komi K.M. Fiaboe, David Bautze, Noah Adamtey
      Intensification of agriculture, combined with poor agronomic practices have increased the incidence of plant parasitic nematodes (PPN) and other soil pathogens in East Africa, which consequently affects crop productivity in small holder farms. The objective of the study was to assess the effectiveness of farming systems in management of PPN and to recommend the best practice to farmers. Therefore, two field trials were established, one in farmer fields and one on-station, using maize (Zea mays L.), intercropped with beans (Phaseolus vulgaris L.) and in rotation with beans as a sole crop. Organic farming (that received compost, Tithonia diversifolia and neem cake (Azadirachta indica)) was compared to conventional farming (that received fertilizer and nematicide), farmer practice (that received manure, Tithonia diversifolia and wood ash), and a farm with no input application (control). After three years of continuous cultivation, twelve genera of PPN were recovered from soil and/or root samples from the trials. Under inter- and sole-cropping at both sites, the abundance of PPN including Pratylenchus and Meloidogyne were significantly reduced in the organic system compared to the conventional, farmer practices and control. Organic farming was effective in reducing the genera of PPN below the control for a longer period (4 months) compared to conventional farming and farmer practice (2 months). The findings demonstrated the potential of organic farming in the suppression of PPN at the farmer level. Policy development and extension services can therefore consider organic farming as an alternative method in managing soil-borne nematodes in small holder farms in sub-Saharan Africa. However, further studies are required on other crops, in dry areas and the period to top-dress with organic amendments to assure effective suppression of PPN in organic farming.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.07.002
      Issue No: Vol. 247 (2017)
  • Impact of deforestation on soil fertility, soil carbon and nitrogen
           stocks: the case of the Gacheb catchment in the White Nile Basin,
    • Authors: Henok Kassa; Stefaan Dondeyne; Jean Poesen; Amaury Frankl; Jan Nyssen
      Pages: 273 - 282
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Henok Kassa, Stefaan Dondeyne, Jean Poesen, Amaury Frankl, Jan Nyssen
      The evergreen forests of southwest Ethiopia are important for soil fertility sustenance and climate change mitigation. However, the increasing human population and expansion of agricultural land have led to deforestation. We determine the effect of deforestation on soil fertility, soil carbon and nitrogen stocks and hypothesize that tropical forests and agroforestry have similar characteristics, in contrast to the deforested areas used as cropland. Hence, soil samples (n=360) have been taken from the natural forest, agroforestry and croplands at four depths (0–20cm, 20–40cm, 40–60cm and 60–80cm) in three altitudinal belts. The topsoil and subsoil physico-chemical characteristics, pH, organic carbon, total nitrogen, available phosphorus, exchangeable calcium, magnesium, cation exchange capacity and exchangeable base cations were significantly higher in both the forest and agroforestry than in croplands, at all elevation zones. Soil organic carbon and nitrogen stocks in soil under forest are similar to those under agroforestry at all elevation zones (0–20cm, 20–40cm, 40–60cm and 60–80cm soil depths). However, soil organic carbon and nitrogen stocks in soil under both forest and agroforestry were significantly different from cropland in all elevation zones at all depths except 60–80cm. The highest total soil organic carbon stocks were recorded in the forest (412Mgha−1 at the FH site and 320Mgha−1 at the FL site) and agroforestry (357Mgha−1 at the DM site, 397Mgha−1 at the ZH site and 363 Mg ha−1 at the ZM site). The total organic carbon loss due to the conversion of forest to cropland ranges from 3.3Mgha−1 y−1 at the FL site to 8.0Mgha−1 y−1 at the FH site. The soil organic carbon and nitrogen losses due to the conversion of forest to cropland are similar to the losses when converting agroforestry to cropland. The total carbon dioxide emission due to the conversion of forest to cropland ranges from 12Mgha−1 y−1 at the FL site to 28Mgha−1 y−1 at the FH site. Agroforestry has the potential to maintain soil fertility, and stores higher soil organic carbon and nitrogen in proportion to the natural forest. Therefore, it can be suggested that agroforestry has a similar capacity as Afromontane forests to sustain soil fertility as well as to regulate greenhouse gas emissions.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.06.034
      Issue No: Vol. 247 (2017)
  • Multitrophic Cry-protein flow in a dual-gene Bt-cotton field
    • Authors: Michael Eisenring; Jörg Romeis; Steven E. Naranjo; Michael Meissle
      Pages: 283 - 289
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Michael Eisenring, Jörg Romeis, Steven E. Naranjo, Michael Meissle
      The transfer of plant-produced insecticidal Cry-proteins in the arthropod food web can be affected by a number of environmental and ecological factors. Despite this fact, most studies documenting multitrophic Cry-protein acquisition patterns in arthropods are conducted under controlled conditions whereas the number of field studies is limited. Such field studies, however, are valuable to understand multitrophic allocation dynamics of Cry-proteins under ecologically realistic conditions and are therefore important for the interpretation and design of laboratory hazard studies on genetically engineered (GE) crops. We thus sampled arthropods and plant structures in a field planted with GE dual-gene cotton plants producing the Cry-proteins Cry1Ac and Cry2Ab from Bacillus thuringiensis Berliner over the growing season. Cry-protein concentrations in field-collected plants, herbivores, and predators were quantified and compared with arthropods subjected to tri-trophic laboratory feeding assays. Both, field studies and laboratory assays showed that Cry-protein concentrations strongly decreased with increasing trophic level to values mostly below the detection limit in predators. Under field conditions, in-planta Cry-protein concentrations varied between plant structures and over the season. Concentrations in arthropods were mainly associated with feeding mode, feeding location on the plant, and to a lesser degree seasonality. Compared to plants, arthropods showed lower Cry2Ab:Cry1Ac ratios indicating that Cry2Ab might be less stable than Cry1Ac. Of all predators collected in the field study, we measured highest Cry-protein levels in jumping and crab spiders, predatory flies and some predatory hemipterans. This emphasizes the relevance of these groups for the risk assessment of GE cotton.

      PubDate: 2017-07-12T13:07:01Z
      DOI: 10.1016/j.agee.2017.07.009
      Issue No: Vol. 247 (2017)
  • Source identification and budget evaluation of eroded organic carbon in an
           intensive agricultural catchment
    • Authors: Yixia Wang; Nufang Fang; Lisha Tong; Zhihua Shi
      Pages: 290 - 297
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Yixia Wang, Nufang Fang, Lisha Tong, Zhihua Shi
      Soil erosion affects the redistribution of soil and associated soil organic carbon (SOC) from different landforms, and it has significant implications regarding the fate of eroded SOC and terrestrial carbon sequestration. Despite the importance of soil erosion, few studies have evaluated the sources and budget of eroded SOC in the Loess Plateau region, which suffers from severe soil erosion. Based on an 11.3m check dam sediment profile, we used the 137Cs activity and extreme rainfall events as dating methods to date sediment sequences. In addition, the natural abundance levels of the stable carbon isotope (δ13C) of bulk organic matter and a two-end-member mixing model were used to discriminate the sources of eroded SOC from different siltation stages retained by the check dam in an intensive agricultural catchment of the Loess Plateau, China. The eroded SOC captured by the check dam was compared to potential source materials from different landscape units, which included sloping cropland and gully surface soils (0–5cm). The results showed that the check dam intercepted 98.5 Gg of eroded soil and 172.6Mg of SOC. The eroded SOC was primarily sourced from sloping cropland, which contributed to 81.3% of the total SOC retained by the check dam, whereas the gully soils contributed to 18.7% during the entire siltation stage. Additionally, the contribution of sloping cropland to eroded SOC increased from 1960 to 1990 as a result of rainfall and anthropogenic activities. A total of 89.7Mg SOC was lost during soil erosion processes at a rate of 0.17Mg ha−1 yr−1 and accounted for approximately 30% of the total eroded SOC exported from the eroding areas. Our results indicate that the soil erosion process has been an important net source of SOC in the study catchment. The check dam served as a carbon storage and sequestration structure for the hilly loess region due to its beneficial conditions for carbon sequestration over broad temporal and spatial distributions.
      Graphical abstract image

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.011
      Issue No: Vol. 247 (2017)
  • Chromoleana odorata fallow-cropping cycles maintain soil carbon stocks and
           yam yields 40 years after conversion of native- to farmland, implications
           for forest conservation
    • Authors: Serge-Pacôme A.Y. Kassi; Armand W. Koné; Jérôme E. Tondoh; Bernard Y. Koffi
      Pages: 298 - 307
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Serge-Pacôme A.Y. Kassi, Armand W. Koné, Jérôme E. Tondoh, Bernard Y. Koffi
      Natural ecosystem conversion to agriculture is known to alter soil carbon dynamic. Following such conversion in many tropical areas, land undergoes fallow-cropping cycles where fallows are invaded by the pantropical weed Chromoleana odorata. This study was undertaken in the forest-savanna interface area of Côte d’Ivoire to evaluate the impact of these cycles on soil carbon stocks (SOCS) and yam yields, decades after natural ecosystem conversion. Trials involved four treatments including yam farms in forest (FOR, n=10), in forest-derived C. odorata fallows (FoDCo, n=7), in savanna (SAV, n=3) and in savanna-derived C. odorata fallows (SaDCo, n=3). Prior to turning plots to farms, soil was sampled in the 0–10, 10–20 and 20–40cm layers for physical, chemical and microbial parameters. Since forest and savanna soils were different in granulometry, FoDCo was compared to FOR, and SaDCo to SAV. The soil organic matter and nutrient concentrations in the 0–10cm soil layer in FoDCo and FOR were similar, except for available P which was higher in the former. SaDCo was higher than SAV in terms of SOC, available P, mineral N, and NO3-N:Mineral N ratio. With regard to SOCS, value in FoDCo equalled that in FOR regardless of soil layers (63.2±4.4 and 63.7±4.6 Mg ha−1 in 0–40cm layer, respectively). However, SOCS significantly increased in SaDCo relative to SAV in the 0–20cm (31.4±2.7 vs. 24.2±2.1 Mg ha−1). Consistently, yam yield in FoDCo was like that in FOR while it doubled in SaDCo compared to SAV, with SOC, CEC and mineral N as the controlling factors. The major finding of this study is that the predominance of C. odorata in fallow phases allows at least for maintenance of SOCS and yam yields decades after natural ecosystem conversion to farmland. Furthermore, evidence of the feasibility of the “4 per mille” was given. These results are highly useful in forest protection strategies since farmers usually cut forest for yam cropping.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.044
      Issue No: Vol. 247 (2017)
  • Long-term effects of grass-clover leys on the structure of a silt loam
           soil in a cold climate
    • Authors: Nicholas Jarvis; Johannes Forkman; John Koestel; Thomas Kätterer; Mats Larsbo; Astrid Taylor
      Pages: 319 - 328
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Nicholas Jarvis, Johannes Forkman, John Koestel, Thomas Kätterer, Mats Larsbo, Astrid Taylor
      Grass/legume leys are commonly included in the crop rotation in mixed farming systems in cold or humid regions in order to sustain the supply of nutrients and maintain soil fertility. Leys are also known to sequester soil organic carbon and also improve the structural stability and mechanical properties of soil. However, few studies have investigated the long-term effects of ley rotations on the architectural properties of the structural pore space in soil. We investigated the effects of grass/clover leys on soil structure in the topsoil and upper subsoil of a silt loam in a long-term field trial established in 1956 at Offer in northern Sweden. This experiment includes four treatments with varying proportions of ley (1, 2, 3 or 5 years) in 6-year rotations. We used X-ray tomography to quantify topsoil structural pore space at a resolution of 65μm in the first year of arable cropping following the ley break, a few weeks after sowing in spring. Earthworm populations were quantified by both hand-sorting and chemical extraction, while near-saturated infiltration was measured as a proxy for soil structure in the upper subsoil. In the topsoil, the treatments with a greater proportion of ley had larger organic carbon contents, smaller bulk densities and larger porosities. However, effects of crop rotation on the pore space were limited to pores smaller than 65μm, as no treatment effects were found for the volume, size distribution, connectivity or complexity of the X-ray imaged pore space, even though the grass-clover leys promoted larger numbers and biomass of topsoil-dwelling earthworm species. Furthermore, no positive effects of grass/clover leys on organic carbon content and soil structure were found in the subsoil. The macropore infiltration capacity in upper subsoil was generally very small (overall median value of 3mmh−1) indicating a lack of functional macroporosity below plough depth. Consistent with these results, no individuals of deep-burrowing earthworm species were found at the site, while previous observations showed only shallow rooting, both of which are attributed to the cold climate and poor subsoil drainage.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.042
      Issue No: Vol. 247 (2017)
  • Responses of soil N-fixing bacteria communities to Amaranthus retroflexus
           invasion under different forms of N deposition
    • Authors: Congyan Wang; Jiawei Zhou; Jun Liu; Kun Jiang; Daolin Du
      Pages: 329 - 336
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Congyan Wang, Jiawei Zhou, Jun Liu, Kun Jiang, Daolin Du
      Soil N-fixing bacteria communities (SNB) can increase soil N availability, which can facilitate invasions of many kinds of invasive plant species. Meanwhile, variability in the forms of anthropogenic N deposition can mediate obvious shifts in both soil physicochemical properties and soil microbial communities (especially SNB). This can alter the soil micro-ecological mechanisms of plant invasions via changes in soil characteristics and soil microbial communities, especially SNB. This study uses next-generation high throughput sequencing technology to provide insight into the effects of invasion by Amaranthus retroflexus L. on the structure and diversity of SNB under different forms of simulated N deposition (SND). Soil pH under A. retroflexus invasion under various forms of SND was 8.08% lower than controls under a NH4-N treatment (P < 0.05), 15.15% lower than controls under a NO3-N treatment (P< 0.05), and 6.57% lower than controls under CO(NH2)2-N and Mix-N treatments (P < 0.05). Meanwhile, soil pH was one of the most important environmental variables explaining changes in the structure and diversity of SNB. The total number of species of SNB under A. retroflexus invasion was approximately 13.13% higher than controls for the NH4-N treatment (P > 0.05), 11.00% higher than controls for the NO3-N treatment (P > 0.05), 39.42% higher than controls for the CO(NH2)2-N treatment (P < 0.05), and 27.67 higher than controls for the Mix-N treatment (P < 0.05). The positive effects mediated by the combined treatments of A. retroflexus invasion and SND may be ascribed to enhanced soil nutrient content (especially N), which can enhance the abundance of the nifH gene. The effects of A. retroflexus invasion on the total number of species of SNB under organic and mixed-N addition were greater than under inorganic N addition. This may be a consequence of a disturbance of the balance of inorganic to organic N for SND, as a result of the addition of a single form of inorganic N, which can diminish the stimulatory effects of soil nutrient content on SNB under inorganic N. Another potential cause of this pattern may be stronger acidification under inorganic N addition, which can exert more pronounced effects on SNB. LEfSe analysis showed that some species changed significantly under A. retroflexus invasion in the presence of SND (i.e., Rhodobacteraceae under NH4-N and Proteobacteria under CO(NH2)2-N). Thus, A. retroflexus invasion in the presence of SND caused obvious shifts in certain species of SNB and increased the total number of species of SNB in particular, to facilitate its further invasion.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.012
      Issue No: Vol. 247 (2017)
  • Diverse cropping systems enhanced yield but did not improve yield
           stability in a 52-year long experiment
    • Authors: Audrey St-Martin; Giulia Vico; Göran Bergkvist; Riccardo Bommarco
      Pages: 337 - 342
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Audrey St-Martin, Giulia Vico, Göran Bergkvist, Riccardo Bommarco
      Farm specialization and associated simplification of the crop rotation raise concern about the ability of cropping systems to deliver high and stable yield in the long-term. Exploiting data from 52 years of a long-term experiment in Southern Sweden, we investigated impacts of three conventional cropping systems (‘crop-livestock’, ‘specialized’, and ‘diverse’) on yield levels and stability of winter and spring wheat. For winter wheat, the ‘diverse’ and ‘crop-livestock’ systems enhanced yields by 15% compared to the ‘specialized’ system. For spring wheat, the ‘crop-livestock’ system tended to show higher yield than the ‘diverse’ one. The stability analysis showed that in winter wheat the three systems lead to equally stable yields considering year-to-year variability. For spring wheat, the ‘crop-livestock’ system tended to perform better in favorable years relative to the other systems. Overall, the results revealed that for winter wheat cultivation, stockless diverse cropping provides an valid alternative to crop-livestock in the context of specialized farming where crop and livestock are separated.
      Graphical abstract image

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.013
      Issue No: Vol. 247 (2017)
  • Soil water effects of agroforestry in rainfed jujube (Ziziphus jujube
           Mill.) orchards on loess hillslopes in Northwest China
    • Authors: Qiang Ling; Xiaodong Gao; Xining Zhao; Jun Huang; Hongchen Li; Lusheng Li; Wenhao Sun; Pute Wu
      Pages: 343 - 351
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Qiang Ling, Xiaodong Gao, Xining Zhao, Jun Huang, Hongchen Li, Lusheng Li, Wenhao Sun, Pute Wu
      Soil water is the most critical factor influencing the growth and productivity of crops on the Loess Plateau of China. The popular clean-cultivation soil management practice in rainfed jujube orchards in this region causes a variety of environmental problems, including serious soil erosion and soil quality degradation. Agroforestry is a promising avenue to cope with this problem but its effect on soil water in the root zone is yet to be elucidated. In this study, two different agroforestry systems were established in jujube orchards on the hillslopes of the Loess Plateau, to test the effects on root-zone soil water. The Hemerocallis fulva and fodder Brassica napus were planted between jujube rows. The results showed that both agroforestry systems clearly improved soil water at depths of 0–20cm and 20–60cm under jujube trees, however, they apparently reduced the inter-row soil water at depths of 60–120cm and 120–180cm in different years compared to the control. A simple method, based on the difference of soil water content between inter-row crops and jujube trees (SWDR), was introduced to judge the possibility of water competition happening. The analyses based on this method showed that in the jujube- H. fulva intercropping system, H. fulva frequently competed soil water with jujube trees in the 0–120cm depth primarily in the relatively dry period (May to July). However, there was almost no water competition occurred in the jujube-B. napus treatment. Overall, fodder B. napus may be more appropriate than Hemerocallis fulva for intercropping with jujube trees. The results here can provide insights into ground management practice of sloping orchards in water-limited areas.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.031
      Issue No: Vol. 247 (2017)
  • Long-term functional structure and functional diversity changes in
           Scottish grasslands
    • Authors: Robin J. Pakeman; Richard L. Hewison; David Riach; Julia M. Fisher; Sonja Hurskainen; Debbie A. Fielding; Ruth J. Mitchell
      Pages: 352 - 362
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Robin J. Pakeman, Richard L. Hewison, David Riach, Julia M. Fisher, Sonja Hurskainen, Debbie A. Fielding, Ruth J. Mitchell
      Analysis of changes in functional traits and functional diversity offers a means of identifying the main environmental drivers of change, the impacts of that change on community assembly and the consequence of change on ecosystem function and service delivery. Changes in key traits and functional diversity in Scottish grasslands were analysed for a resurvey of 561 grasslands sampled an average of 40 years apart and these changes correlated with changes in environmental drivers. There were clear differences between the responses of different grassland habitats; more productive habitats showed evidence of increased agricultural utilisation, whereas more unproductive habitats showed evidence of reduced exploitation. This was echoed in an increase in Functional Richness in unproductive habitats and a decrease in productive ones; the latter indicating increased habitat filtering in the heavily utilised, productive habitats. There were also overall shifts to later-flowering species and less availability of resources for pollinators in less productive habitats. Models relating changes in traits to the environment had little power, but did indicate the importance of pollution and that recovery from the peak in livestock numbers between the surveys had not fully worked through. Similarly, changes in functional diversity were poorly explained by changes in environmental drivers, though increased rainfall had positive impacts on Functional Evenness and Richness. Functional Divergence (measured by Rao’s Q) was, however, strongly linked to changes in species traits over time. Scottish grasslands have diverged in how they have been utilised; more productive grasslands have been exploited more, resulting in shifts towards species with more exploitative growth strategies, a narrower range of growth and investment strategies, but a reduction in competitive dominance. The less productive grasslands appear to be utilised less, with shifts towards more conservative growth strategies and reduced habitat filtering, and the potential to deliver greater ecosystem multifunctionality. Resource declines for pollinators appeared to be universal across all grassland habitats.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.033
      Issue No: Vol. 247 (2017)
  • The benefits of hedgerows for pollinators and natural enemies depends on
           hedge quality and landscape context
    • Authors: Michael P.D. Garratt; Deepa Senapathi; Duncan J. Coston; Simon R. Mortimer; Simon G. Potts
      Pages: 363 - 370
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Michael P.D. Garratt, Deepa Senapathi, Duncan J. Coston, Simon R. Mortimer, Simon G. Potts
      Ecological intensification advocates the harnessing of regulating and supporting ecosystem services to promote more sustainable food production, and this relies on effective management of non-cropped habitats. Hedgerows are an important component of the landscape in many farming systems across the world, management of which provides a potential mechanism to enhance ecological intensification. Here we investigate the value of hedgerows in Southern England as a source of functionally important taxa, and how hedgerow quality and local landscape composition impact on their potential contribution to sustainable agriculture in arable landscapes. We show that hedgerows are a source habitat for many natural enemies which spill over into neighbouring fields, and that hedgerows provide a valuable forage resource and corridor for movement of pollinators. Hedgerow quality affects these benefits and continuous unbroken hedgerows, with a high diversity of woody species, are more valuable for the provision of bumblebees and Linyphiid spiders, while the presence of trees within the hedgerow supports Lycosid spiders. Floral resources, beyond the woody hedgerow species themselves, are also a key forage resource for hoverflies. The impact of these hedgerows on invertebrate abundance is moderated by local landscape, and hedgerows are a more valuable forage resource for pollinators in more intensely managed landscapes. Our study shows that in order to support abundant and a broad range of natural enemies and pollinators in agricultural landscapes, both hedgerows and local semi-natural habitats need to be protected and managed. The benefit of hedgerows, as a habitat for functionally important taxa depends on hedgerow quality and management practices such as avoiding gaps, high hedge species diversity and maintaining an abundant understory of plants, can improve their value for ecological intensification.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.048
      Issue No: Vol. 247 (2017)
  • Determining optimum nitrogen input rate and optimum yield-scaled nitrous
           oxide emissions: Theory, field observations, usage, and limitations
    • Authors: Dong-Gill Kim; Donna Giltrap
      Pages: 371 - 378
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Dong-Gill Kim, Donna Giltrap
      Nitrous oxide (N2O) is one of the major greenhouse gases causing global warming and climate change. Recently, studies showed that the nitrogen (N) input producing optimum amount of crop yields may minimise yield-scaled N2O emissions in agricultural production. Objectives of the study were to 1) investigate theoretical backgrounds of yield, N2O emission, and yield-scaled N2O emission responses to N input, 2) suggest concepts of optimum N input rate and optimum yield-scaled N2O emission and derive equations for them and 3) test with field observations, and 4) assess usage and limitations and suggest future studies. We have proposed a concept and equations for optimum N input rate and optimum yield-scaled N2O emission, and applied them to field-measured data from 10 independent experimental studies worldwide. Field-measured data showed that the suggested equations could be used to determine optimum N input rate and optimum yield-scaled N2O emissions. However, in some cases, any N input resulted in increased yield-scaled N2O emission and minimum yield-scaled N2O emissions occurred when N input was zero. The suggested optimum N input rate and optimum yield-scaled N2O emission can be useful indicators for best management practices to mitigate greenhouse gas emissions and secure food supply. However, in some cases, taking into account yields and N2O emissions separately is required to identify best management practices. Further studies are needed to better understand the characteristics of yield-scaled N2O emissions response to N input and its use for management purposes.
      Graphical abstract image

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.003
      Issue No: Vol. 247 (2017)
  • Comparison of invertebrate biodiversity in New Zealand apple orchards
           using integrated pest management, with or without codling moth mating
           disruption, or organic pest management
    • Authors: Louise A. Malone; Elisabeth P.J. Burgess; Emma I. Barraclough; Joanne Poulton; Jacqui H. Todd
      Pages: 379 - 388
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Louise A. Malone, Elisabeth P.J. Burgess, Emma I. Barraclough, Joanne Poulton, Jacqui H. Todd
      On-farm biodiversity is increasingly perceived as an indicator of sustainable practices. However, in-depth examinations of the influence of management on the components of this diversity (specific taxa, feeding guilds, pests, ecosystem service providers, native taxa, and so on) are still lacking for many crops and growing regions. To compare the diversity of invertebrates in commercial apple orchards using three different pest management systems (Integrated Fruit Production with or without codling moth mating disruption and certified organic), we collected taxa from five of each type of orchard in Hawke’s Bay, New Zealand. We used pitfall traps, branch tapping and sticky traps to collect 210,829 specimens, representing 764 taxa, during two sampling sessions: December 2011 and February/March 2012. Groundcover plant communities in the alleys between tree rows were not detectably different among the three orchard types. Multivariate analysis showed that the composition of invertebrate communities sampled from organic orchards differed significantly from those in orchards using the two different integrated pest management systems and that the use of codling moth disruption in the integrated systems had no discernible impact on invertebrate biodiversity in those orchards. Sub-group analysis revealed some differences between integrated and organic orchards for herbivores, predators and parasitoids, but not omnivores, detritivores and fungivores. Native or endemic species comprised 40% of taxa in all three orchard types, and there were no detectable differences in the composition of these assemblages among orchards. Assemblages of apple pests in organic orchards differed significantly from those in the other orchard types, but this effect was lost if Edwardsiana froggatti, which was abundant in organic orchards, was omitted from the analysis. All orchard types had similar assemblages of key natural enemies, suggesting that current integrated pest management systems employed on apple orchards in New Zealand have similar impacts to organic systems in this respect.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.06.046
      Issue No: Vol. 247 (2017)
  • The effect of water table decline on plant biomass and species composition
           in the Zoige peatland: A four-year in situ field experiment
    • Authors: Rui Cao; Xue Wei; Yangheshan Yang; Xinqiang Xi; Xinwei Wu
      Pages: 389 - 395
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Rui Cao, Xue Wei, Yangheshan Yang, Xinqiang Xi, Xinwei Wu
      The Zoige peatland is the largest alpine peatland in the world, and it is suffering the threat of water table decline. Plant productivity and species composition are important to ecosystem carbon sequestration and soil carbon input in peatlands. We examined the responses of plant community composition and biomass accumulation to water table decline to better understanding the responses of this peatland to environmental changes. A four-year in situ field experiment was conducted involving three treatments: deep, shallow, and control water tables, which were achieved by experimental drainage with 50cm, 20cm, and 0cm deep ditches, respectively. Experimental drainage decreased the annual mean height of water table by ca. 12cm and 15cm (relative to the control) in the shallow and deep water table treatments, respectively, over the four years. The response of aboveground plant biomass (APB) to water table decline declined in the first year, remained unchanged in the second year and increased during the third and fourth years. However, water table decline had a non-significant effect on belowground plant biomass. This duration-dependent response of APB can be attributed to the changes in community species composition during the study years. Specifically, the negative effect of water table decline in the first year was due to the significant decrease in APB of hygrophytes (sedges and rushes). In the second year, although water table decline significantly increased APB of mesophytes (grasses and forbs), this increase was offset by the decrease in APB of hygrophytes, leading to a neutral effect. In both the third and fourth years, the extent of the increase in APB of mesophytes (typically the forb species Anemone trullifolia var. linearis) was greater than that of the decrease in APB of hygrophytes, leading to a positive effect. Our results indicate that short-term decline of the water table may increase the primary productivity by shifting dominant species of hygrophytes to mesophytes in the Zogie peatland.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.008
      Issue No: Vol. 247 (2017)
  • Increased root growth and nitrogen accumulation in common wheat following
           PGPR inoculation: Assessment of plant-microbe interactions by ESEM
    • Authors: Cristian Dal Cortivo; Giuseppe Barion; Giovanna Visioli; Monica Mattarozzi; Giuliano Mosca; Teofilo Vamerali
      Pages: 396 - 408
      Abstract: Publication date: 1 September 2017
      Source:Agriculture, Ecosystems & Environment, Volume 247
      Author(s): Cristian Dal Cortivo, Giuseppe Barion, Giovanna Visioli, Monica Mattarozzi, Giuliano Mosca, Teofilo Vamerali
      The use of plant growth-promoting rhizobacteria (PGPR) meets the current need to reduce nitrogen input in order to attain greater sustainability in the production of crops, particularly cereals. This study investigated whether a commercial bio-fertiliser containing a consortium of PGPR and N-fixing bacteria (Azospirillum spp., Azoarcus spp. and Azorhizobium spp.) affects shoot and root growth, N accumulation and grain yield in common wheat (Triticum aestivum L.). Trials were conducted in a fertile, silty loam soil, firstly in rhizoboxes, by applying bacteria either as a seed-coating inoculum or by foliar+soil spraying, and then in the field by spraying the canopy at the tillering stage with decreasing levels of N fertilisation (160, 120 and 80kgha−1) in two consecutive years. Culm height, leaf chlorophyll content, nitrogen accumulation and yield were recorded above ground, while below ground Root Length Density (RLD) patterns were investigated by soil coring and image analysis at the flowering stage. Environmental Scanning Electron Microscope (ESEM) imaging revealed an excellent ability of bacteria to adhere to the surface of intact leaves and roots, and to colonise both leaf mesophyll and root vascular tissues in aseptic conditions. Bacteria increased the number of root tips and ramifications (+65% vs. non-inoculated controls) in sterilised rhizobox soil, regardless of the method of application, and the volumetric root length density in the open field with medium (+29%) and high (+11%) N supply, resulting in greater N accumulation (about +25kgha−1). Although the N dose had clear positive effects, no significant variations in grain yield (only+1–3% vs. non-inoculated controls) or other agronomic parameters could be ascribed to bacteria inoculation. The conclusion drawn is that the use of a combination of PGPR and N-fixing bacteria offers an opportunity to improve root growth in wheat and increase plant resilience to environmental stresses, and helps to reduce N losses from agricultural ecosystems thereby offering partial fertiliser savings within crop rotations.

      PubDate: 2017-07-24T10:46:53Z
      DOI: 10.1016/j.agee.2017.07.006
      Issue No: Vol. 247 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
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