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Showing 1 - 200 of 3175 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 14)
Academic Pediatrics     Hybrid Journal   (Followers: 28, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 90, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 33, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 6, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 376, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 235, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 10, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 25, 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: 3)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 6, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 6)
Acute Pain     Full-text available via subscription   (Followers: 14)
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: 7)
Additive Manufacturing     Hybrid Journal   (Followers: 9, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3)
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: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 12, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 27, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 10, 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: 14, 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: 2, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 28, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 7, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 3)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 27, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 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: 19, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.223, h-index: 22)
Advances in Dermatology     Full-text available via subscription   (Followers: 14)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 10)
Advances in Digestive Medicine     Open Access   (Followers: 8)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 21)
Advances in Ecological Research     Full-text available via subscription   (Followers: 42, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 27, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 6)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 42, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 7)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 54, 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: 14, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 7)
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: 9, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 1, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 14, 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: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
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: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 1)
Advances in Organ Biology     Full-text available via subscription   (Followers: 1)
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: 6, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, 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: 10)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 7)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 59)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.1, h-index: 2)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 374, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 9, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 29, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
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: 46, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 333, 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: 6, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 9, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 429, 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: 31, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 43, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 1)
Agriculture and Natural Resources     Open Access   (Followers: 2)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 56, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 9)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access   (Followers: 1)
Algal Research     Partially Free   (Followers: 9, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
Alpha Omegan     Full-text available via subscription   (SJR: 0.121, h-index: 9)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 48, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 50, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 50, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 42, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 10, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 31, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 26, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 32, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 42, 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: 190, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 62, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 27, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 37, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 61, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 14)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 4, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 39, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 166, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 10, 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   (Followers: 1)

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Journal Cover Agricultural Water Management
  [SJR: 1.546]   [H-I: 79]   [43 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-3774
   Published by Elsevier Homepage  [3175 journals]
  • Agroecosystem tradeoffs associated with conversion to subsurface drip
           irrigation in organic systems
    • Authors: Jennifer E. Schmidt; Caitlin Peterson; Daoyuan Wang; Kate M. Scow; Amélie C.M. Gaudin
      Pages: 1 - 8
      Abstract: Publication date: 1 April 2018
      Source:Agricultural Water Management, Volume 202
      Author(s): Jennifer E. Schmidt, Caitlin Peterson, Daoyuan Wang, Kate M. Scow, Amélie C.M. Gaudin
      Subsurface drip (SSD) irrigation is becoming increasingly prevalent in drought-prone irrigated agroecosystems thanks to greater yields and irrigation water productivity (IWP) and decreased weed pressure. However, potential tradeoffs for soil health and biogeochemical cycles remain unclear, especially in organic systems that rely on soil ecosystem services and biological processes for productivity. Gains in IWP and weed control were evaluated with respect to shifts in soil biological and physicochemical parameters in an organic processing tomato (Solanum lycopersicum L.) agroecosystem. Yield, IWP, and spatial distribution of soil resources and microbial processes were measured in furrow and SSD irrigated organic processing tomato on long term organic fields. Higher IWP and lower weed density under SSD confirm known benefits, while altered distributions of inorganic N, salinity, microbial activity, and C/N cycling enzyme activities as a function of shifts in soil moisture highlight the far-reaching impacts of irrigation management on soil organic C (SOC) and N dynamics regulating resource availability. Decreased macroaggregate formation and greater unprotected C under SSD indicate that altered soil wetting patterns may reduce the C sequestration potential of irrigated land. Previously unknown tradeoffs should be integrated to develop irrigation strategies that maintain current and future sustainability and productivity of organic tomato agroecosystems.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.02.005
      Issue No: Vol. 202 (2018)
  • Best management irrigation practices assessed by a GIS-based decision tool
           for reducing salinization risks in olive orchards
    • Authors: Juan M. Peragón; Francisco J. Pérez-Latorre; Antonio Delgado; Tibor Tóth
      Pages: 33 - 41
      Abstract: Publication date: 1 April 2018
      Source:Agricultural Water Management, Volume 202
      Author(s): Juan M. Peragón, Francisco J. Pérez-Latorre, Antonio Delgado, Tibor Tóth
      Sustainable irrigation should rely on the efficient use of water while avoiding soil degradation. To this end, decision tools for assessing best management practices are necessary. There is, however, little evidence of efficient tools to assess best irrigation practices at regional scale taking into account water quality to avoid soil degradation and negative impacts on crop yields. The objective of this work was the performance of a GIS-based decision tool to assess best irrigation management practices aimed at reducing the negative effect of salts in irrigation water in olive orchards. The approach in this tool involved first the blending of two sources of available waters, surface and underground, and when necessary, the application of leaching fractions (LF). We tested this tool in the province of Jaen (south Spain) as representative area of olive cultivation in Mediterranean environments. In 82.4% of the study area, the use of one of both water sources with electrical conductivity (ECw) below the defined threshold (1.8 dS m−1) was possible without blending. Water blending for achieving optimal irrigation water quality was possible in 16% of the irrigated land. In other 9.8% of the irrigated land, leaching fraction was required to achieve the defined salinity threshold. In the area where water blending was possible, this strategy resulted in the best irrigation water efficiency (IWE) estimated for the province. With water blending and LF when necessary, the annual gross income in the province can be increased by 80 mill €. The proposed GIS-base decision tool is easy to update for different crops and regions. It is able to transform and combine geographical data and value judgments for decision making in irrigation at a regional scale with a view of achieving the most efficient irrigation water use while avoiding negative effects on crop and soil due to water salinity.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.02.010
      Issue No: Vol. 202 (2018)
  • Almond tree response to a change in wetted soil volume under drip
    • Authors: M. Espadafor; F. Orgaz; L. Testi; I.J. Lorite; O. García-Tejera; F.J. Villalobos; E. Fereres
      Pages: 57 - 65
      Abstract: Publication date: 1 April 2018
      Source:Agricultural Water Management, Volume 202
      Author(s): M. Espadafor, F. Orgaz, L. Testi, I.J. Lorite, O. García-Tejera, F.J. Villalobos, E. Fereres
      Under localized irrigation, even when applying non-limiting amounts of water, there could be transpiration (T) limitations due to a limited wetted soil volume. To study under field conditions how drip-irrigated almond trees responded to a change in wetted soil volume, two treatments were established in summer 2012 in a drip irrigated almond orchard in Cordoba, Spain. One treatment (“Large volume”) was initially irrigated with micro-sprinklers (MS) to wet the entire ground surface, and then reverted to drip irrigation, while other was always kept under drip irrigation (“Small volume”). Continuous monitoring of T and measurements of soil moisture content, tree water status and trunk growth were carried out. Even though trees in both treatments were supplied with sufficient water, the MS application induced an increase in T and an improvement in water status in “Large volume” relative to “Small volume”. A reduction in the hydraulic resistance of the tree was also detected in “Large volume”, as well as an enhancement in canopy conductance and tree growth. We concluded that there are situations in the field where almond tree transpiration is limited by an insufficient wetted soil volume, even when supplied with adequate water, due to a high hydraulic resistance during times of high evaporative demand.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.01.026
      Issue No: Vol. 202 (2018)
  • Deficit irrigation and transparent plastic covers can save water and
           improve grapevine cultivation in the tropics
    • Authors: Jefferson Rangel da Silva; Weverton Pereira Rodrigues; Luciene Souza Ferreira; Wallace de Paula Bernado; Jéssica Sousa Paixão; Angelica Eloisa Patterson; Katherine Fraga Ruas; Leandro Hespanhol Viana; Elias Fernandes de Sousa; Ricardo Enrique Bressan-Smith; Stefano Poni; Kevin Lee Griffin; Eliemar Campostrini
      Pages: 66 - 80
      Abstract: Publication date: 1 April 2018
      Source:Agricultural Water Management, Volume 202
      Author(s): Jefferson Rangel da Silva, Weverton Pereira Rodrigues, Luciene Souza Ferreira, Wallace de Paula Bernado, Jéssica Sousa Paixão, Angelica Eloisa Patterson, Katherine Fraga Ruas, Leandro Hespanhol Viana, Elias Fernandes de Sousa, Ricardo Enrique Bressan-Smith, Stefano Poni, Kevin Lee Griffin, Eliemar Campostrini
      We examined the interactive effects of deficit irrigation and transparent plastic covering (TPC) on key physiological traits in tropically grown grapevines. ‘Niagara Rosada’ grapevine (Vitis labrusca) was subjected to both Regulated Deficit Irrigation (RDI) and Partial Rootzone Drying (PRD) while being grown under a TPC to address the following questions: (i) Does the grapevine present anisohydric or isohydric behavior' (ii) How does deficit irrigation affect leaf water potential (Ψ)' (iii) Can RDI and PRD improve plant́s water use efficiency' (iv) How does deficit irrigation affect leaf photochemical and biochemical capacity' (v) What are the effects of deficit irrigation on leaf respiration and leaf carbon balance' (vi) Is it possible to save water without affecting yield and fruit quality' Three water management techniques were applied: full-irrigated (FI): 100% of the crop evapotranspiration (ETc) was supplied to both sides of the root system; RDI: 50% of the ETc was supplied to both sides of the root system; and PRD: 50% of ETc was alternately supplied to only one side of the root system. These irrigation treatments were replicated such that the two plots were either covered by a polyethylene plastic structure or remained uncovered. We found that: (i) ‘Niagara Rosada’ grapevine presented anisohydric behavior; (ii) deficit irrigation did not affect Ψ; (iii) Neither RDI nor PRD had a significant effect on water use efficiency (iv); no limitations by the carboxylation reactions of photosynthesis or Rubisco oxygenation (Vo 1500) were observed, and photochemical capacity was not inhibited; (v) Light and dark leaf respiration rates were not affected by either RDI or PRD and therefore deficit irrigation did not damage the leaf carbon balance; (vi) a considerable volume of water was saved when deficit irrigation was used, without affecting production; (vii) TPC use can be an effective strategy for growing grapevine in tropical conditions.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.02.013
      Issue No: Vol. 202 (2018)
  • The physiological processes and mechanisms for superior water productivity
           of a popular ground cover rice production system
    • Authors: Sen Li; Qiang Zuo; Xinxin Jin; Wenwen Ma; Jianchu Shi; Alon Ben-Gal
      Pages: 11 - 20
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Sen Li, Qiang Zuo, Xinxin Jin, Wenwen Ma, Jianchu Shi, Alon Ben-Gal
      Ground cover rice production systems (GCRPS) have been shown to both save water and increase yields compared to traditional paddy rice production systems (TPRPS). Physiological processes and mechanisms explaining the superiority of a popular GCRPS were investigated in a series of hydroponic, soil column and field experiments. Soil water, temperature and nitrogen, leaf gas exchange, plant water and nitrogen, growth and yield, transpiration, and water productivity were analyzed. Compared to TPRPS, plant available soil inorganic nitrogen was generally improved under GCRPS due to a combination of higher soil temperature and less nitrogen loss through non-physiological water consumption, especially during the early growing season. Consequently, more nitrogen was absorbed by plants under GCRPS except serious drought conditions, accompanied by higher nitrogen contents in plant tissues. Preferable specific leaf nitrogen might lead to higher leaf photosynthetic rate under optimal water conditions and less decrease relative to leaf transpiration rate under water stress. Therefore, rice under GCRPS grew faster with much more biomass and grain yield while transpiration consumption was limited in spite of the fact that the number of tillers and therefore leaf area were increased relative to TPRPS, resulting in superior water productivity. Compared to TPRPS, the root system under GCRPS was limited, but it could absorb enough water and nutrients (especially nitrogen) to support a relatively large canopy even when under water stress, which might be attributed to its higher nitrogen content and thus stronger activity.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.002
      Issue No: Vol. 201 (2018)
  • Potato growth, yield and water productivity response to different
           irrigation and fertilization regimes
    • Authors: Anita Ierna; Giovanni Mauromicale
      Pages: 21 - 26
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Anita Ierna, Giovanni Mauromicale
      To achieve improvement in irrigation management and maximize water productivity (WP), knowledge on potato crop growth and seasonal crop evapotranspiration (ETc) in relation to combined irrigation and fertilization, are needed. In a two-year experiment conducted in Sicily (South Italy), the combined effects of 3 irrigation levels [irrigation only at plant emergence, irrigation at 50% of maximum evapotranspiration (ETm) and irrigation at 100% ETm] and 3 N-P-K fertilization rates (low: 50, 25 and 75 kg ha−1, medium: 100, 50 and 150 kg ha−1 and high: 300, 100 and 450 kg ha−1 of N, P2O5 and K2O) on ETc, crop growth rate, aboveground dry biomass and tuber dry yield, sink/source (tuber yield/aboveground biomass yield) ratio, water productivity and crop drought response factor, were studied. Irrigation water amounts were 25 mm in plots irrigated only at plant emergence in both years, 87 and 96 mm in plots irrigated at 50% of ETm, 174 and 192 mm in plots irrigated at 100% of ETm, respectively in the two years. Irrigation based on 100% of ETm + high rate of N-P-K fertilization proved the best combination to promote ETc, crop growth, and improve aboveground biomass, tuber yield, and sink/source ratio but not WP. Fertilization played a crucial role in enhancing WP of this crop especially in plots irrigated only at plant emergence, where both low and medium fertilization rates allowed maximizing WP (2.3 kg m−3 dry weight) ensuring an acceptable tuber yield (about 3.7 t ha−1 dry weight). These results are of considerable importance to farmers to achieve more efficient and rational use of water by potato grown in very limited water availability environments.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.008
      Issue No: Vol. 201 (2018)
  • Border irrigation performance with distance-based cut-off
    • Authors: Mohamed Khaled Salahou; Xiyun Jiao; Haishen Lü
      Pages: 27 - 37
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Mohamed Khaled Salahou, Xiyun Jiao, Haishen Lü
      Border irrigation is widely practised for winter wheat production on the North China Plain. Winter wheat is mainly irrigated with groundwater as a supplement to insufficient precipitation to maintain high agricultural production. As a result of the increased demands for water, groundwater levels have declined. Therefore, improvements to border irrigation performance and water use efficiency are urgently needed. The objective of this study was to determine the optimal distance at which to cut off inflow under different inflow rate conditions in closed-ended border systems. The experimental treatments included three inflow rates (high, moderate, and low, with average rates of 6.91 l s−1 m−1, 4.95 l s−1 m−1, and 2.81 l s−1 m−1, respectively) and three cut-off ratios (CRs) arranged in three replications at the CAS Ecological Agricultural Experiment Station in Nanpi, Hebei Province, China. The surface irrigation hydraulic simulation model WinSRFR was used to examine the sensitivity of the existing design to a range of bottom slopes, surface roughness values, and inflow rates to demonstrate the robustness of the solutions in terms of their application efficiency and low-quarter distribution uniformity. The results present the optimum CR values for different inflow rate conditions to maximize irrigation performance. The results indicate that irrigation performance above the optimum CR values for high, moderate, and low inflow rates is not very sensitive to bottom slope, and no substantial changes in performance were noted when Manning’s roughness coefficient was between 0.04 and 0.09. A set of inflow rate ranges that corresponds to the recommended CRs that could achieve high irrigation performance is presented.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.014
      Issue No: Vol. 201 (2018)
  • Comparison of methods to determine the microbial quality of alternative
           irrigation waters
    • Authors: Hsin-Bai Yin; Jitendra Patel
      Pages: 38 - 45
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Hsin-Bai Yin, Jitendra Patel
      The availability of water for crop irrigation is decreasing due to droughts, population growth, and pollution. Implementation of the Food Safety and Modernization Act (FSMA) for irrigation water standards will discourage growers to use poor microbial quality water for produce crop irrigation. We evaluated the applicability of a novel concentrator method for assessment of microbiological quality of alternative waters including secondary-treated wastewater (STWW), roof-harvest rainwater (RHW), and creek water (CW) in comparison to the standard membrane filtration method. Water samples of 100 ml were filtered through a 0.45 μm membrane filter using a vacuum manifold or concentrated to ∼250 μl using the innovative concentrator. Then they were directly enumerated on specific agars, or enriched to monitor the populations of fecal bacterial indicators (Escherichia coli, enterococci, total and fecal coliforms) and bacterial pathogens (Salmonella, Listeria monocytogenes, and E. coli O157:H7). Presumptive pathogens were confirmed by real-time quantitative PCR. In total, 25 samples of alternative water were analyzed including 7 STWW, 9 RHW, and 9 CW. No significant differences between both detection methods were observed when enumerating indicator bacterial populations and detecting the presence of pathogens in RHW and CW samples. Recovery of fecal coliforms in STWW samples by concentrator analysis was significantly lower than the membrane filtration technique. Results suggest that performance of the concentrator method is equivalent to membrane filtration method in determining the microbiological quality of CW and RHW waters; the type of the water sources may influence the accuracy and sensitivity of the concentrator analysis.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.012
      Issue No: Vol. 201 (2018)
  • Surface irrigation simulation-optimization model based on meta-heuristic
    • Authors: Mahmood Akbari; Mahdi Gheysari; Behrouz Mostafazadeh-Fard; Mohammad Shayannejad
      Pages: 46 - 57
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Mahmood Akbari, Mahdi Gheysari, Behrouz Mostafazadeh-Fard, Mohammad Shayannejad
      Simulation-optimization models are valuable tools for determining the optimal performance of systems. The main objective of this research was to develop and validate EDOSIM (Evaluation, Design, and Optimization of Surface Irrigation Model) as a simulation-optimization model for surface irrigation systems. For simulation, which consisted of the design or evaluation of basin, border and furrow irrigation, the Volume Balance model was used. For optimization, twenty meta-heuristic algorithms were applied. In this model, based on irrigation, the volume of infiltrated water to soil was calculated without having advance and recession data. The hydraulic objective function was used to minimize the linear combination of seven performance indicators. Regarding the optimization of the objective function, the functional, multi-dimensional, static, constraint, continuous, single-objective, and meta-heuristic optimizations were applied. Data obtained from fifteen experimental fields were used for the validation of simulation, algorithms parameters setting, and validation of optimization. Comparison of the simulation results of the EDOSIM model with those of the Hydrodynamic model of SIRMOD software showed the good performance of EDOSIM model and the proposed method for estimating the volume of infiltration with RMSE = 0.068, R2 = 0.988, CRM = 0.005 and NRMSE = 4.2%. The Shuffled Complex Evolution (SCE) algorithm was found to be the best algorithm for the optimization of fields; in all fields, the objective function was decreased (improved). Comparison of the objective function of the EDOSIM model with eight solvers of Optimization and Global Optimization Toolboxes of MATLAB software also revealed the superiority of the EDOSIM model for optimization.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.015
      Issue No: Vol. 201 (2018)
  • Repellency-induced runoff from New Zealand hill country under pasture: A
           plot study
    • Authors: Michael Bretherton; David Horne; H.A. Sumanasena; Paramsothy Jeyakumar; David Scotter
      Pages: 83 - 90
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Michael Bretherton, David Horne, H.A. Sumanasena, Paramsothy Jeyakumar, David Scotter
      Soil water repellency is a common phenomenon which develops when surface soils become dry in summer and autumn. It is claimed that repellency is likely to result in a lower infiltration rate and a concomitant increase in surface runoff, particularly on slopes. This study quantifies the effect of water repellency on runoff from a series of small plots on a range of slopes (20° and 30°) and aspects (N, S and E) in a hilly landscape in the south-east of the North Island of New Zealand. The plots (1 m wide and 2 m long) were set up to capture runoff via a slotted PVC pipe and measure it using tipping bucket apparatus: at each of the slope/aspect locations there were duplicate plots. A meteorological station was also established at the site along with TDR probes to measure soil moisture down to 300 mm depth. When moist, the soil at the site had a very high infiltrability (>1.5 mm/min). On nine occasions, runoff was measured (ranging from 1 to 59% of rainfall) when the soil surface was dry and rainfall was intense (greater than 0.1 mm/min). However, during the two-year study period, this repellency-induced runoff equated to only 5% of the total rainfall. Furthermore, the infiltration rate of initially dry, repellent soil (ranging from 0.2 to 0.6 mm/min) partly recovered over a ten-minute period (0.6–1.0 mm/min) and, with sufficient rainfall, repellency completely disappeared within two days. The transitory nature of water repellency was confirmed in an experiment on large soil slabs conducted in the laboratory where repellency-induced runoff was observed to largely disappear over a period of 30 min. Overall, it is concluded that soil water repellency does not play a major role in the soil water balance of the hill country at the study site.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.013
      Issue No: Vol. 201 (2018)
  • Assessing of an irrigation and fertilization practice for improving rice
           production in the Taihu Lake region (China)
    • Authors: Jiaguo Jiao; Kun Shi; Peng Li; Zhen Sun; Dali Chang; Xueshan Shen; Di Wu; Xiuchao Song; Manqiang Liu; Huixin Li; Feng Hu; Li Xu
      Pages: 91 - 98
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Jiaguo Jiao, Kun Shi, Peng Li, Zhen Sun, Dali Chang, Xueshan Shen, Di Wu, Xiuchao Song, Manqiang Liu, Huixin Li, Feng Hu, Li Xu
      To address the global environmental and resource crisis, integrated, efficient, and sustainable agricultural practices need to be developed. We examined the effects of combining one of two irrigation methods (i.e., controlled irrigation and conventional flooding irrigation) with one of four different levels of nitrogen fertilizer applications (N; 300 (N0), 270 (N1), 240 (N2), and 180 kg N ha−1 (N3)) on grain yield, water use efficiency, and N production efficiency in rice. Additionally, we analyzed nitrogen leaching at different soil depths (20 cm and 80 cm) using lysimeters and N2O emission using a polyvinyl chloride chamber for each of the combinations examined. We found that the irrigation regime and level of N application significantly affected rice yield, and the rice yield in the controlled irrigation treatment was higher than that in the conventional flooding irrigation treatment by 2.12%–12.30%. Of all the treatments, combining controlled irrigation with the N1 fertilizer application resulted in the greatest grain yield. Loss of N was mainly caused by nitrate leaching. Controlled irrigation and reducing the amount of N fertilizer applied in the soil reduced N leaching, and increased the N production efficiency, while increasing N2O emission. Furthermore, water use efficiency was increased under controlled irrigation conditions, but reduced when less N fertilizer was applied. Thus, an agricultural regime that uses less water and lower amounts of N fertilizer than are currently being used in standard practices would likely increase yield and N production efficiency in soils, while reducing potential N leaching; however, the N2O emissions would also increase.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.020
      Issue No: Vol. 201 (2018)
  • Understanding surface water–groundwater interactions for managing large
           irrigation schemes in the multi-country Fergana valley, Central Asia
    • Authors: Mirzakhayot Ibrakhimov; Usman Khalid Awan; Biju George; Umar Waqas Liaqat
      Pages: 99 - 106
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Mirzakhayot Ibrakhimov, Usman Khalid Awan, Biju George, Umar Waqas Liaqat
      Traditionally, surface water supplies are the sole sources to satisfy crop water requirements in large irrigation schemes such as those in the Fergana Valley, Central Asia. Recent studies indicate that 23–30% of these requirements are met from shallow groundwater, but this is not usually quantified. To manage favorable groundwater levels – i.e., without increasing soil salinity and nutrient leaching and reducing crop yields – information on, and quantification of, groundwater recharge and discharge rates at large spatial and temporal scales, as well as understanding their mechanisms of interaction, is indispensable. With the aim to quantify groundwater recharge, discharge and their interaction, a conceptual water balance model at a scale of a Water Consumers’ Association was established on a monthly basis for a 10-year period. Average groundwater recharge was estimated as 780 ± 75.7 mm, representing 62% of surface water supplies. The highest average annual recharge (930 mm) driven by excessive precipitation and water supply was in 2010 and the lowest (667–726 mm) was in years of lower water availability: 2006–2008 and 2012. The net groundwater recharge was 82.4 ± 79 mm, and determined the groundwater level fluctuations. The highest positive net groundwater recharge rate (247 mm) and the shallowest groundwater level (123 cm) also occurred in 2010. The negative net recharge in 2006 (–11 mm), 2008 (–41 mm) and 2012 (–5 mm) indicated deeper groundwater levels during these periods. The groundwater recharge values were excessively high even for this large irrigation scheme. To save limited freshwater resources, groundwater discharge should be reduced, with one option being to reduce excessive drainage outflow.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.016
      Issue No: Vol. 201 (2018)
  • Analysis of kinetic energy distribution of big gun sprinkler applied to
           continuous moving hose-drawn traveler
    • Authors: Maosheng Ge; Pute Wu; Delan Zhu; Lin Zhang
      Pages: 118 - 132
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Maosheng Ge, Pute Wu, Delan Zhu, Lin Zhang
      Kinetic energy of droplets from big gun sprinklers relates closely to the infiltration process and soil erosion, as well as severely affects the energy consumption of hose-drawn travelers. However, research work related to the kinetic energy distribution of big gun sprinklers is seldom performed. In this study, The radial water application distribution, droplet size distribution, and droplet velocity distribution of a big gun sprinkler were measured. Based on the experimental data, a calculation method was developed to determine the kinetic energy of big gun sprinkler under stationary and moving states. Volume weighted mean particle size and the corresponding equivalent landing velocity were adopted as the feature size and velocity of the point located at any distance from the sprinkler. The droplets’ landing velocities present a logarithmic relationship with droplet size and velocities rise with the increase of droplet size. The operating pressure should not be lower than 0.2 MPa since the peak value of specific power will rise rapidly below this operating pressure. For positions receiving the same kinetic energy, obvious difference may exist in the amount of water and the dynamic process curves of specific power. With the increase in travel speed of the hose-drawn traveler, both the cumulative kinetic energy and the irrigation duration decrease proportionally. Compared to the spray plate sprinklers applied to center pivots, the big gun sprinkler shows a milder precipitation process, but the water application lasts longer and carries more kinetic energy, reaching 2- 4 times for the same amount of water. The infiltration rate of each location decreases linearly along with an increase in distance to the travel lane, and the infiltration rate decreases to approximately 20 mm/h at the end of the spraying area.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.009
      Issue No: Vol. 201 (2018)
  • Effects of straw mulching and plastic film mulching on improving soil
           organic carbon and nitrogen fractions, crop yield and water use efficiency
           in the Loess Plateau, China
    • Authors: Qin’ge Dong; Yuchen Yang; Kun Yu; Hao Feng
      Pages: 133 - 143
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Qin’ge Dong, Yuchen Yang, Kun Yu, Hao Feng
      A field experiment was conducted in the Loess Plateau of Northwest China to study the effects of plastic film mulching and straw mulching on soil water, soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN), dissolved organic carbon (DOC) and nitrogen (DON), crop yield and water use efficiency under winter wheat (Tricicum aestivum L.)—summer maize (Zea mays L.) double-cropping system conditions using the following three cultural practices: (i) traditional plough with no mulching (CK), (ii) traditional plough with plastic film mulching (PM), and (iii) traditional plough with straw mulching (SM). Soil water contents were measured by the gravimetric method. SOC was determined using the dichromate oxidation method. TN was analyzed by the Kjeldahl method. MBC and MBN were determined using the chloroform fumigation extraction method. DOC and TDN were determined following Jones’ procedures proposed by Jones and Willett (2006). The results showed that soil water was higher under the PM treatment than under the SM treatment and mainly changed in the upper 60 cm soil layer. Compared with the CK treatment, the concentrations of SOC and TN under the SM treatment were increased by 16.9% and 7.7% at the 0–10 cm soil depth, respectively, and the PM treatment had the similar SOC and TN concentrations. Compared with the CK treatment, soil C:N ratio was increased under the SM treatment by 6.2% (P < 0.05), and that under the PM treatment was decreased by 5.2% (P < 0.05) after three years. The concentrations of MBC under the PM and SM treatments were significantly increased by 42.0% and 24.1%, respectively, and MBN under the PM treatment was significantly increased by 5.6% at 0–10 cm soil depth after the maize season. Compared with the CK treatment, DOC was significantly increased by 21.0% under the SM treatment and decreased by 13.1% under the PM treatment, and DON was significantly increased by 10.5% under the SM treatment and decreased by 4.3% under the PM treatment at the 0–10 cm soil depth after the maize season. Relative changes of labile soil organic carbon and nitrogen fractions were more sensitive than that of SOC and TN. The relative decline or increase of labile soil organic carbon and nitrogen fractions was on average almost 13.6% for the mulching practices. Compared with the CK treatment, the average maize yields under the PM and SM treatments were increased by 26.4% and 9.8%, and the average wheat yields under the PM and SM treatments were increased by 21.3% and 7.4%, respectively. The average water use efficiencies under the PM and SM treatments were 24.5%, 8.8% in winter wheat and 22.9%, 6.3% in summer maize higher than that under the CK treatment, respectively. Our results suggested that plastic film mulching could be used as an effective practice to improve low soil quality with adequate nitrogen and increase crop yield and water use efficiency in the Loess Plateau, China.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.01.021
      Issue No: Vol. 201 (2018)
  • Drought stress in sunflower: Physiological effects and its management
           through breeding and agronomic alternatives
    • Authors: Mubshar Hussain; Shahid Farooq; Waseem Hasan; Sami Ul-Allah; Mohsin Tanveer; Muhammad Farooq; Ahmad Nawaz
      Pages: 152 - 166
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Mubshar Hussain, Shahid Farooq, Waseem Hasan, Sami Ul-Allah, Mohsin Tanveer, Muhammad Farooq, Ahmad Nawaz
      Drought is the most important crop production limiting factor in the changing climate scenario and its intensity is predicted to increase in future. Sunflower is an important oilseed crop having 8% share in the world oilseed production. Although, it is a moderately drought tolerant crop, severe drought causes reduction in the seed and oil production. Therefore, to ensure sustainable sunflower achene and oil production, it is very important to understand the relationship among the physiological, biochemical, genetic and agronomic basis of drought for its sustainable management. Impact of drought stress on various aspects of sunflower has been reported earlier but there is not a single study describing the physiological, biochemical and genetic basis of drought in sunflower at molecular and crop level. In this review manuscript, influence of drought on sunflower achene yield and oil quality has been analyzed critically at both cell, plant and crop level, and the possible management options to mitigate the severity of the drought stress are proposed. Available literature describing the impact of drought stress on physiological and biochemical aspects (like, photosynthesis, water relations, nutrient uptake and oxidative damage), morphological and growth parameters and achene yield and oil quality has been discussed critically. Based on the discussion on the impact of drought stress, various management strategies, such as breeding for drought tolerance (conventional or biotechnological), exogenous application of hormones and osmoprotectants, seed treatment and soil nutrient management has been reviewed and discussed. It is concluded from discussion that sunflower responds to water stress by osmotic adjustments, turgor maintenance, carbon assimilation maintenance and hormonal regulations. A comprehensive research on integration of different management options, including agronomic management, conventional breeding and modern biotechnological advances, is needed for the sustainable improvement of sunflower achene yield and oil quality under drought stress. This may also contribute significantly under a climate change scenario.
      Graphical abstract image

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.01.028
      Issue No: Vol. 201 (2018)
  • Simulating weather effects on potato yield, nitrate leaching, and profit
           margin in the US Pacific Northwest
    • Authors: Prem Woli; Gerrit Hoogenboom
      Pages: 177 - 187
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Prem Woli, Gerrit Hoogenboom
      The US Pacific Northwest is one of the most productive potato regions in the world. However, due to the high inputs, nitrate contamination of groundwater is frequently documented, and maximizing crop productivity while minimizing nitrate leaching is still challenging. The goal of this study was to assess how irrigation level, soil type, and weather condition during various phenological phases would affect tuber yield and the associated nitrate leaching and profit margin. The Cropping System Model (CSM)-SUBSTOR-Potato was used to simulate the response variables for various scenarios that comprised two soil types, five irrigation levels, five phenological phases, five weather conditions, and 75 years of historical weather data for 3 locations in this region. The simulation results showed that nitrate leaching was higher with a higher amount of irrigation and for a lighter soil. Tuber yield and profit margins were lowest for a lighter soil and highest for 300 mm of irrigation for an extremely-drained soil and 400 mm of irrigation for a well-drained soil. The increase in profit margins with an increase in total irrigation up to 400 mm was highest for a well-drained soil, whereas the decrease in profit margins with an increase in irrigation beyond a total amount of 300 mm was larger for an extremely-drained soil. For the different types of weather scenarios that were studied, only severe hot weather had an impact on tuber yield and profit margins. The reduction was highest at tuber bulking and significant when hot weather continued from sprout development through tuber bulking or from plant establishment through tuber maturation. However, any change in weather condition from the long-term average for any growth phase did not affect leaching. These findings might be helpful to potato growers in this region to protect their potatoes from adverse weather conditions through appropriate mitigation strategies.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.01.023
      Issue No: Vol. 201 (2018)
  • Estimation and partitioning of actual daily evapotranspiration at an
           intensive olive grove using the STSEB model based on remote sensing
    • Authors: Melanie Häusler; Nuno Conceição; Luca Tezza; Juan M. Sánchez; Manuel L. Campagnolo; Andreas J. Häusler; João M.N. Silva; Thorsten Warneke; Georg Heygster; M. Isabel Ferreira
      Pages: 188 - 198
      Abstract: Publication date: 31 March 2018
      Source:Agricultural Water Management, Volume 201
      Author(s): Melanie Häusler, Nuno Conceição, Luca Tezza, Juan M. Sánchez, Manuel L. Campagnolo, Andreas J. Häusler, João M.N. Silva, Thorsten Warneke, Georg Heygster, M. Isabel Ferreira
      This study is based on the application of an existing simplified two-source energy balance (STSEB) model, using medium-resolution satellite imagery (Landsat) to estimate instantaneous (at the satellite overpass time) and daily actual crop evapotranspiration (ET a ) over an intensive olive grove. Daily values were obtained by the use of the evaporative fraction method and corrected for latent heat, available energy, and evaporative fraction biases (beta-factor correction). Model estimates were compared to ground-based measurements. Heat flux densities (eddy covariance method) were recorded, and five Landsat images at approximately monthly intervals were used, covering our study site in 2011. Comparison with ground measurements showed a maximum difference of −0.6 mm day−1 before, and 0.2 mm day−1 after beta-factor correction for the main plot. The experimental site consisted of a main plot exposed to deficit irrigation, and two small subplots where—during a limited period of time (six weeks)—one was temporarily not irrigated, and the other well-irrigated for reference. One Landsat image was available for this limited period of time. Additionally, the STSEB algorithm was tested for partitioning evapotranspiration into its evaporation and transpiration components. Evaporation estimated from the STSEB model was compared with evaporation estimated from a model adjusted from local lysimeter measurements. Transpiration data obtained from calibrated sap flow measurements were, after local calibration, also compared to model estimates. Model results agreed with the measured data, showing) under- and overestimation for transpiration and evaporation, respectively.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.01.027
      Issue No: Vol. 201 (2018)
  • Tempo-spatial controls of total coliform and E. coli contamination in a
           subtropical hilly agricultural catchment
    • Authors: Fei Xue; Jialiang Tang; Zhixin Dong; Dong Shen; Haowen Liu; Xifeng Zhang; Nicholas M. Holden
      Pages: 10 - 18
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): Fei Xue, Jialiang Tang, Zhixin Dong, Dong Shen, Haowen Liu, Xifeng Zhang, Nicholas M. Holden
      Waterborne microbial pollution remains poorly understood in developing countries, especially in rural areas. The transport of point (e.g. untreated domestic wastewater) and non-point sources of fecal bacteria such as Total coliform (TC) and Escherichia coli (E. coli) and their spatial and temporal patterns were identified in a typical small agricultural catchment in a hilly area of subtropical China. Over the sampling area, 460 water samples from 24 sites were collected during a period of 12 months, and a remediation option using an existing ecological ditch was evaluated. The results showed that 70% surface water samples exceeded the guideline of 1000 TC MPN 100 ml−1 in the catchment. Also, 90% of groundwater samples exceeded the guideline of 10 MPN E. coli 100 ml−1 for safe drinking water. Higher concentrations of TC and E. coli occurred both in the warm and rainy season in surface water and groundwater. TC and E. coli concentrations in surface water tributaries and groundwater near residential areas were greater than those in downstream water bodies. A 300 m long vegetated ecological ditch greatly reduced average concentrations TC of 97.7% and E.coli of 99.5%. TC and E. coli concentrations were significantly correlated with electrical conductivity and turbidity, both in surface water and groundwater, indicating that mixtures of organic colloids and sediment were the most important transport vector for pathogens. However, temperature only showed a controlling effect on bacteria concentration in groundwater in this particular catchment. The current research could help predict microbial risks and establish integrated management strategy to improve water quality in the hilly agricultural catchments in the subtropical region.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.034
      Issue No: Vol. 200 (2018)
  • Integrated management of agricultural water resources among paddy farmers
           in northern Iran
    • Authors: Faramarz Hadizadeh; Mohammad S. Allahyari; Christos A. Damalas; Mohammad Reza Yazdani
      Pages: 19 - 26
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): Faramarz Hadizadeh, Mohammad S. Allahyari, Christos A. Damalas, Mohammad Reza Yazdani
      While growing populations and increasing water requirements are a certainty, there is a big uncertainty about how these requirements will be affected by human activities. Given the importance of integrated management as a tool for optimum management of water resources by farmers under water deficit conditions, the general objective of the present study was to identify factors underpinning integrated management of agricultural water by paddy farmers in Langarud County of Guilan Province in northern Iran. For this purpose, a survey of paddy farmers was conducted. The irrigation canals were the most widely used source of water in local paddy farms (44.0%) followed by rivers (28.1%). The majority of the paddy farmers (70.6%) were using more than one water resource for irrigating their fields. The farmers believed that ‘post-rice succession planting’, ‘cropping pattern and land use change’, and ‘fuel subsidy’ were the most important factors affecting integrated management of agricultural water. Using exploratory factor analysis, five factors affecting integrated management of agricultural water among paddy farmers were revealed: i) availability of irrigation infrastructure, ii) cropping pattern, iii) supportive role of local institutes, iv) irrigation experience, and v) traditional beliefs. These factors together captured 60.1% of the total variance in the management of agricultural water. According to cluster analysis and factors identified by factor analysis, paddy farmers using integrated water resources were classified in three clusters: i) modernists (37.1%) who showed the strongest motivation response to changes and they generally showed a high reaction to most motivational factors, ii) conservatives (34.7%) who tended to resist the change and were more satisfied with the current conditions, and iii) holists (28.2%) who showed a favorable response to motivational factors, but they were not pioneers. The findings provide a better understanding of paddy farmers’ drivers for integrated management of agricultural water that could assist policy-makers to focus on strategies for improving irrigation water productivity and supporting more sustainable water use in rice production in the study area and similar arid cropping regions of the world.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2017.12.031
      Issue No: Vol. 200 (2018)
  • Calibration of compensation heat pulse velocity technique for measuring
           transpiration of selected indigenous trees using weighing lysimeters
    • Authors: C.M. Tfwala; L.D. van Rensburg; Z.A. Bello; S.R. Green
      Pages: 27 - 33
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): C.M. Tfwala, L.D. van Rensburg, Z.A. Bello, S.R. Green
      The compensation heat pulse velocity (CHPV) is one of the most widely used methods to measure sap flow in woody plants. However, the accuracy of this method has not been fully explored especially for indigenous tree species of South Africa. The aim of this study was to evaluate the accuracy of the CHPV method in quantifying tree transpiration for selected tree species. Three indigenous trees sampled in a monolith form; black karee (Sersia lancea), buffalo thorn (Ziziphus mucronata) and wild olive (Olea africana) grown on weighing lysimeters (1 m × 1 m × 1.3 m) were installed with CHPV probes to measure sap flow on the stem half hourly, simultaneously with lysimeter measurements of transpiration. The surfaces of the lysimeters were covered with a 10 cm layer of Styrofoam, overlain by a 2 cm layer of gravel to minimize evaporation to a negligible level. Both the lysimeter and CHPV measurements were divided into two sets. The first set was used to develop tree specific calibration equations as well as an equation combining the three species used, here called a combination equation. The second set of data was used for validating the equations. Transpiration rates ranged from negligible at night to daily peaks of 3.5, 1.7 and 1.4 L h−1 for buffalo thorn, black karee and wild olive, respectively. Good agreement indices between CHPV and lysimeters were obtained when using both the tree specific equations and combination equation across species (D = 0.778–1.000, RMSE = 0.001–0.017 L h−1, MAE < 0.001 L h−1 and MBE = −0.0007 to 0.0008 L h−1). It was concluded that the CHPV method can accurately measure tree water use, and therefore can be useful for water resources management in forested areas.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.005
      Issue No: Vol. 200 (2018)
  • Sharing a river: Potential performance of a water bank for reallocating
           irrigation water
    • Authors: Nazaret M. Montilla-López; José A. Gómez-Limón; Carlos Gutiérrez-Martín
      Pages: 47 - 59
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): Nazaret M. Montilla-López, José A. Gómez-Limón, Carlos Gutiérrez-Martín
      This paper presents an ex-ante policy analysis of the implementation of a publicly run active water bank operating at the basin level designed to temporarily reallocate water resources between farmers considering different scenarios of reduced water availability (cyclical scarcity due to droughts). For this purpose, the Guadalquivir River Basin, located in southern Spain, is used as a case study. Fifteen representative farm types were considered to simulate water trading through public tender for purchasing and selling temporary water rights. The model is built at the basin level to estimate the aggregate demand and supply curves to establish expected exchange prices, volumes of water traded, enhancement in economic efficiency and improvement in rural development as measured by employment generation. The simulation results show that the proposed water bank encourages water transfers from 19% of the total water used in the case of a moderate drought to almost 40% in the case of an extreme drought, significantly reducing the economic and labor demand losses due to water shortages. The public water agency can recover all of the incurred water bank operation costs by implementing a €0.01/m3 price differential between purchase and sale prices without meaningfully affecting the performance of the water bank. Thus, we conclude that the implementation of this kind of water bank during droughts would be useful in mitigating negative effects of droughts. Thus, policymakers are encouraged to create water banks as an effective instrument to cope with droughts.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.025
      Issue No: Vol. 200 (2018)
  • Effect of manifold layout and fertilizer solution concentration on
           fertilization and flushing times and uniformity of drip irrigation systems
    • Authors: Pan Tang; Hong Li; Zakaria Issaka; Chao Chen
      Pages: 71 - 79
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): Pan Tang, Hong Li, Zakaria Issaka, Chao Chen
      Applying fertilizer through drip irrigation system is a very important method to save fertilizer and labour. Three manifold layouts (water supply in one end for transversal drip tapes (M1), water supply in both ends for transversal drip tapes (M2) and water supply in one end for longitudinal drip tapes (M3)) and four different fertilizer solution concentrations (50.00 g L−1 (C1), 66.67 g L−1 (C2), 100 g L−1 (C3) and 200 g L−1 (C4)) were selected to investigated the effect of the manifold and concentration on water fertigation uniformity. Results showed that the emitter at the extreme end of the manifold needed more time to clean the rudimental fertilizer in the drip tapes. The minimal flushing time increased from 8 to 13, 4 to 7 and 7 to 12 min with increasing the fertilizer concentration from C1 to C4 for M1, M2 and M3, respectively. The drip irrigation system needed more time for flushing to reduce the risk of emitter clogging when a higher fertilizer solution concentration was applied. In order of performance, M2 had the highest water and fertilizer uniformity, followed by M3 and lastly by M1. The fertilizer solution concentration had no significant effect on water distribution. However, it had a significant effect on fertilizer distribution. The mass of the applied fertilizer for the drip tapes close to the inlet increased with increasing fertilizer solution concentration from C1 to C4, which indicated that higher fertilizer solution concentration can result in lower fertilizer distribution uniformity. There was a significant effect of the manifold layout on water uniformity. The fertilizer concentration and the interaction between manifold layout and concentration had no significant effect on the water uniformity. Similarly, both the manifold layout and concentration had a significant effect on fertilizer uniformity. The interaction between manifold layout and concentration had a significant effect on the Christiansen’s uniformity (CU) and distribution uniformity (DU) for fertilizer, whilst, a significant effect on emission uniformity (EU) was not found. The manifold layout and fertilizer solution concentration should therefore be considered in the design and operation of fertigation system.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2018.01.010
      Issue No: Vol. 200 (2018)
  • Mekong River Delta farm-household willingness to pay for salinity
           intrusion risk reduction
    • Authors: Tien Dung Khong; Michael D. Young; Adam Loch; Jayanthi Thennakoon
      Pages: 80 - 89
      Abstract: Publication date: 1 March 2018
      Source:Agricultural Water Management, Volume 200
      Author(s): Tien Dung Khong, Michael D. Young, Adam Loch, Jayanthi Thennakoon
      Sea level rise and upstream development is causing salinity intrusion in Vietnam’s Mekong River Delta (MRD) and, as a consequence, agricultural productivity is declining. As the Vietnamese government and local communities search for a solution, it has become apparent that there are insufficient public resources to build the dykes necessary to control this problem. So, we employ a referendum contingent valuation methodology (CVM) to determine whether or not farm households might be willing to pay for part of the cost of a salinity intrusion risk reduction program. We find that farm households are willing to contribute funds to such a program. In areas where salinity intrusion is already reducing productivity, farm households are willing to contribute US$2.58 per month. In areas where salinity intrusion is expected to be reducing productivity by 2030, willingness to contribute is US$1.99 per month. Surprisingly, in MRD areas where salinity intrusion is not expected within the next 15 years, willingness to contribute remains positive at US$1.32 per month. These findings have local, national and international implications that require careful consideration. In passing, we make a methodological observation that a treatment model including ‘do not know’ responses provides consistent results with conventional referendum elicitation procedures.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.010
      Issue No: Vol. 200 (2018)
  • Using gene expression programming in monthly reference evapotranspiration
           modeling: A case study in Egypt
    • Authors: Mohamed A. Mattar
      Pages: 28 - 38
      Abstract: Publication date: 2 February 2018
      Source:Agricultural Water Management, Volume 198
      Author(s): Mohamed A. Mattar
      The Penman-Monteith FAO-56 equation requires the complete climatic records for estimating reference evapotranspiration (ET o ). The present study is aimed at developing and evaluating a gene expression programming (GEP) model for estimating mean monthly ET o by using minimal amount of climatic data. The data used in the analysis are collected from 32 weather stations in Egypt through the CLIMWAT database. The results showed that the accuracy of the GEP model significantly improved when either mean relative humidity (RH) or wind speed at 2-m height (u 2) was used as additional input variables. The GEP model with the inputs as maximum and minimum air temperature, RH, and u 2 showed the lowest root mean square error (0.426 mm d−1 and 0.430 mm d−1) and, the highest coefficient of determination, (0.963 and 0.962) overall index of model performance (0.960 and 0.960), and index of agreement (0.991 and 0.990) for training and testing sets, respectively. Comparing the results of GEP models with other empirical models showed that the GEP technique are more accurate and can be employed successfully in modelling ET o .

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.017
      Issue No: Vol. 198 (2018)
  • Comparison of the water budget for the typical cropland and pear orchard
           ecosystems in the North China Plain
    • Authors: Yucui Zhang; Huimin Lei; Wenguang Zhao; Yanjun Shen; Dengpan Xiao
      Pages: 53 - 64
      Abstract: Publication date: 2 February 2018
      Source:Agricultural Water Management, Volume 198
      Author(s): Yucui Zhang, Huimin Lei, Wenguang Zhao, Yanjun Shen, Dengpan Xiao
      The North China Plain (NCP) has a severe water shortage. About 70% groundwater has been exploited for irrigation. Winter wheat – summer maize and pears are typical representative cereal crops and commercial fruit trees in this area, respectively. Water budget for the typical cropland and orchard ecosystems has a significant importance for agricultural production, especially in the NCP. Therefore, evapotranspiration (ET) and water balance were studied in the annual winter wheat – summer maize rotation (cropland) and pear orchard. Latent and sensible heat fluxes were measured by eddy covariance. Annual ET for pear trees was 764 mm and for both crops was 690 mm. The difference of ET between these two ecosystems was about equal to one irrigation. Transpiration was the main loss with the mean proportion of 63% for crops and 76% for pear trees. Wheat growth period is in the dry season and requires much more irrigation than maize. Mainly transpiration (80%) occurred from April through September in the both ecosystems which was also the growing period for pear trees. The annual precipitation was 469 mm and 444 mm in the pear orchard and cropland, respectively, although 80% of it occurred from June to September. Compared with the precipitation, annual mean water deficit was 294 mm for the pear trees and 244 mm for crops. The water shortage was severe in May while surplus water presented in July and August. Energy and ET fluxes were determined by atmospheric demand and the response of plants as controlled by plant phenology and crop selection. As the water shortage situation becomes more serious in the NCP, sustainability of the agricultural ecosystems could be improved by changing crop planting patterns, specifically, increasing the area ratio of maize to pear trees.

      PubDate: 2018-02-05T12:20:01Z
      DOI: 10.1016/j.agwat.2017.12.027
      Issue No: Vol. 198 (2018)
  • Soil properties and agro-physiological responses of alfalfa (Medicago
           sativa L.) irrigated by treated domestic wastewater
    • Authors: Saloua Elfanssi; Naaila Ouazzani; Laila Mandi
      Abstract: Publication date: Available online 12 February 2018
      Source:Agricultural Water Management
      Author(s): Saloua Elfanssi, Naaila Ouazzani, Laila Mandi
      The aim of this experiment is to evaluate the effect of raw and treated wastewater irrigation on soil and plants in comparison to well water. Three plots planted with Medicago sativa L., were irrigated using water of three different qualities over a period of 9 months covering three crop seasons. Physicochemical and microbial parameters were analyzed in water and soil. Agro-physiological, biochemical and antioxidant enzyme traits in the crops were also assessed. Results of agro-physiological parameters show a positive effect on alfalfa irrigated with domestic wastewater compared to well water, while biochemical parameters (stomatal conductance, chlorophyll fluorescence and total chlorophyll content) were adversely affected in alfalfa irrigated with raw wastewater as compared to treated and well water. The plants irrigated with raw wastewater accumulate more proline and sugar than plants irrigated with treated wastewater and well water. The prevalence of antioxidant enzymes (POD, CAT and MDA) in the plants increased with raw wastewater irrigation, however, it remained within the tolerance levels in both plants irrigated by treated wastewater and well water. All three levels of water treatment demonstrated low content of heavy metals in the soil, indicating a lack of availability for the plants. Moreover, the use of treated wastewater improves physicochemical properties and fertility of the soil compared to well water and enhances crop productivity.

      PubDate: 2018-02-25T18:51:19Z
      DOI: 10.1016/j.agwat.2018.02.003
  • Using saline soil and marginal quality water to produce alfalfa in arid
    • Authors: F.J. Díaz; S.R. Grattan; J.A. Reyes; B. de la Roza-Delgado; S.E. Benes; C. Jiménez; M. Dorta; M. Tejedor
      Pages: 11 - 21
      Abstract: Publication date: February 2018
      Source:Agricultural Water Management, Volume 199
      Author(s): F.J. Díaz, S.R. Grattan, J.A. Reyes, B. de la Roza-Delgado, S.E. Benes, C. Jiménez, M. Dorta, M. Tejedor
      The gradual increase in the amount of land and water resources affected by salt in arid and semi-arid regions requires strategies to optimize the use of these marginal-quality resources. Recent field and greenhouse experiments have demonstrated the potential of growing certain ‘pre-selected’ varieties of alfalfa in highly saline conditions. A greenhouse study was conducted to determine the impact of irrigation with saline groundwater on alfalfa growth and production in saline-sodic soils. The sustainability of the system in terms of forage yield and quality was also evaluated. The study included three varieties of alfalfa (Medicago sativa, vars. SW8421S, PGI908S and WL656HQ) planted in pots filled with saline-sodic soil (Calcic Haplosalids) collected on the island of Lanzarote (Spain) and irrigated for 18 months with increasingly saline water. Although the yield of the alfalfa varieties was reduced by an average of 7, 20, 31 and 46% as the salinity of the irrigation water increased from 0.4 dS m−1 to 2.5, 5.0, 7.5 and 10.0 dS m−1, respectively, their relative salt tolerance, based on the average electrical conductivity of the saturated soil extract (ECe), was much higher than those established in the literature. Based on their nutritional quality, all alfalfa varieties are categorized as ‘supreme’ quality, with metabolizable energy (ME) values in excess of 10 MJ kg−1. Moreover, no detriment to quality was observed at the higher levels of irrigation water salinity. Mineral composition analysis revealed S, K and B levels near or above the established maximum tolerable levels (MTLs) suggesting that this forage could only be safely consumed by ruminants over the long term if combined with other forages with lower mineral content.

      PubDate: 2017-12-26T18:31:50Z
      DOI: 10.1016/j.agwat.2017.12.003
      Issue No: Vol. 199 (2017)
  • Water pricing following rainfall distribution and its implications for
           irrigation agriculture
    • Authors: Sarah Isselhorst; Jonas Berking; Brigitta Schütt
      Pages: 34 - 47
      Abstract: Publication date: February 2018
      Source:Agricultural Water Management, Volume 199
      Author(s): Sarah Isselhorst, Jonas Berking, Brigitta Schütt
      This study uses data from water auctions, conducted by the traditional irrigation community of Vélez Blanco. Water prices are comprehensively compared and statically correlated with local precipitation data on different temporal scales; the data analyzed reach back to 1967. The local prevailing Mediterranean climate is characterized by a mean annual precipitation amount of 419mm, while effective rainfall (≥1mm) occurs averagely at 37days per year. The rainfall distribution data used were of daily, seasonal and annual resolution and are assessed on their influence on the local water price formation. The results were validated with information about local agricultural practices and subjective perceptions of the vega’s status, gained from interviews with local farmers. Results show that high correlation coefficients are achieved when water prices and precipitation data are correlated on a monthly scale. The highest correlation coefficients are achieved with a temporal offset of one month throughout the spring and summer season. Interestingly, neither short term water surplus, nor long term water deficit (consecutive drought years) are clearly reflected. Based on the given data-base, annual rainfall distribution has proven to be a significant factor that influences water price formation in the Vega of Vélez Blanco.

      PubDate: 2017-12-13T06:20:12Z
      DOI: 10.1016/j.agwat.2017.11.018
      Issue No: Vol. 199 (2017)
  • Determining water use efficiency of wheat and cotton: A meta-regression
    • Authors: Yubing Fan; Chenggang Wang; Zhibiao Nan
      Pages: 48 - 60
      Abstract: Publication date: February 2018
      Source:Agricultural Water Management, Volume 199
      Author(s): Yubing Fan, Chenggang Wang, Zhibiao Nan
      A great challenge for agricultural production is to produce more food with less water, which can be possibly achieved by increasing crop water use efficiency (WUE). This study systematically reviewed 52 cases from 49 empirical studies with field experimental results on wheat and cotton. This research investigated yield-water use relations under both furrow and micro irrigation systems, compared optimal water use to achieve maximum WUE and maximum yield, calculated water saving potentials under various scenarios, and evaluated the effects of influential factors using meta-regression analysis. The results suggest that to achieve maximum WUE rather than maximum yield, water use for wheat can be reduced by 30.4% with a grain yield decrease of 14.8%, and water use for cotton can decrease by 51.4% with a yield reduction of 51.7%. Compared with furrow irrigation, micro irrigation reduces wheat water use by 22.7% and increases yield by 36.7%. While for cotton, micro irrigation reduces water use by 36.8% and decrease yield by 21.4%. Under the scenario of a 10% yield reduction, water use decreases by 25% for wheat and by 20–22% for cotton. Compared with maximum yield, other yield levels reduce water use by 2–15% on average for wheat, and by 15–17% for cotton. Achieving maximum WUE reduces water use by 14–31% compared with other sub-optimal WUE levels. The meta-regression analysis showed adoption of micro irrigation systems, and farm management practices on soil and water significantly improved wheat and cotton WUE. Assessments of the publication selection bias and genuine effects illustrate the application of weighted least squares in conducting meta-regression analysis.

      PubDate: 2017-12-26T18:31:50Z
      DOI: 10.1016/j.agwat.2017.12.006
      Issue No: Vol. 199 (2017)
  • Theoretical analysis of the effects of irrigation rate and paddy water
           depth on water and leaf temperatures in a paddy field continuously
           irrigated with running water
    • Authors: Kazuhiro Nishida; Shuichiro Yoshida; Sho Shiozawa
      Pages: 10 - 18
      Abstract: Publication date: 2 February 2018
      Source:Agricultural Water Management, Volume 198
      Author(s): Kazuhiro Nishida, Shuichiro Yoshida, Sho Shiozawa
      Water management techniques such as continuous irrigation with running water (CIRW) have been used by Japanese farmers to control the thermal environment for rice cropping. In this study, to optimize this method to control the thermal environment in paddy fields, theoretical equations for predicting water and vegetation temperatures in a paddy field were obtained. First, the equations to calculate water and vegetation temperatures in a paddy field were obtained by solving the heat balance equations of the paddy water and vegetation, taking into account the effect of horizontal heat convection driven by irrigation. The equations were validated by comparisons with observed water temperatures in a conventional paddy field under CIRW. The calculated changes in water temperatures over time and distance showed good agreement with observed values, with a root mean square error of 0.39°C. This result indicated that the equations satisfactorily expressed the features of paddy water temperature under CIRW. Next, these equations were used to determine the effects of irrigation rate, paddy water depth and wind speed on water and rice plant temperatures. The following results were obtained. 1) The area cooled by CIRW was positively related to irrigation rate and negatively related to water depth. 2) Low water depths were preferable for application of CIRW during the nighttime. 3) Slower wind speeds and latent heat flux from vegetation strengthened the effects of water management on vegetation temperature. The proposed equations and analyses represent the common features of the effect of irrigation on water and vegetation temperatures in a paddy field, and provide quantitative information about the effects of water management techniques on the thermal environment for rice cropping.

      PubDate: 2017-12-13T06:20:12Z
      DOI: 10.1016/j.agwat.2017.11.021
      Issue No: Vol. 198 (2017)
  • Modelling soil water dynamic in rain-fed spring maize field with plastic
    • Authors: Baoqing Chen; Enke Liu; Xurong Mei; Changrong Yan; Sarah Garré
      Pages: 19 - 27
      Abstract: Publication date: 2 February 2018
      Source:Agricultural Water Management, Volume 198
      Author(s): Baoqing Chen, Enke Liu, Xurong Mei, Changrong Yan, Sarah Garré
      Numerical solution of the Richards equation with Hydrus-2D model is a low cost and fast way to get information on spatio-temporal soil water dynamics. Previous researches with Hydrus-2D have developed two different approaches to represent the rainfall infiltration in irrigated field with plastic mulching: ‘BP’ – an approach comprised by bare strip boundary and plastic strip boundary without consideration of film side infiltration;‘BP + ’- an approach comprised by bare strip and plastic strip with integrating the process of film side infiltration by increasing the rainfall infiltration amount in bare strip. Nevertheless, the performance of these approaches has not yet been evaluated in rain-fed fields. Considering much more dominant role of rainfall infiltration in rain-fed agriculture, we tested an additional approach which comprised a bare strip, plastic strip and planting hole (BPH) to take into account the effect of the rainfall canopy redistribution and film side infiltration, and we compared its performance to the two existing approaches. Results suggested BP completely failed to reproduce the soil water content (SWC) in all soil layers of plastic strip and in the deep soil layers of bare strip. BP+ overestimated the SWC in 0–20 cm of the bare strip, while the performance of BPH was acceptable in different positions. After that, we compared the soil water distribution between no-mulched field (NM) and plastic mulched field (PM) with approach BPH. Our simulation showed that the highest SWC in PM occurred near the planting hole, SWC in the center zone of plastic strip was lower, while SWC in the bare strip was lowest. PM improves the soil water availability not only in the plastic strip but also in the bare strip as compared to NM.

      PubDate: 2017-12-26T18:31:50Z
      DOI: 10.1016/j.agwat.2017.12.007
      Issue No: Vol. 198 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
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