for Journals by Title or ISSN
for Articles by Keywords
help

Publisher: Elsevier   (Total: 3043 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

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: 333, 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: 225, 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: 134, 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: 42, 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: 26)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 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: 16)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 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: 310, 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: 408, 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: 187, 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: 9)
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: 164, 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: 158, 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)

        1 2 3 4 5 6 7 8 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover Agricultural Water Management
  [SJR: 1.546]   [H-I: 79]   [38 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-3774
   Published by Elsevier Homepage  [3043 journals]
  • Automated ebb-and-flow subirrigation for citrus liners production. II.
           Pests, diseases and nutrient concentration
    • Authors: Rhuanito Soranz Ferrarezi; Roberto Testezlaf
      Pages: 21 - 32
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Rhuanito Soranz Ferrarezi, Roberto Testezlaf
      Subirrigation has the potential to reduce water and nutrients losses in citrus seedlings production by recirculating fertilizer solution (FS) and eliminating improper disposal of salts into the environment. The objectives of this study were to evaluate the effect of an automated ebb-and-flow system on pest and disease incidence and nutrient concentration of Rangpur lime (Citrus × limonia) liners. Nutrients were determined on plant tissue (shoot and root), substrate, and recirculated FS collected on 121-L water tanks. The treatments were four volumetric water content (VWC) to trigger subirrigation (0.12, 0.24, 0.36 and 0.48m3 m−3), three FS concentrations (25%, 50% and 75% of the fertilizer recommendation) and a control (nursery manual overhead irrigation using breaker nozzles), arranged in a completely randomized 4×3+1 factorial plus design, with three replications. The system was automated by 39 capacitance sensors connected to a data logger, multiplexer and relay drivers, which controlled submersible pumps inside 121-L tanks with different FS. Subirrigation was turned on when VWC dropped below the set thresholds. There was occasional appearance of leaf miners (Phyllocnistis citrella, Lepidoptera: Gracillariidae) and fungus gnats (Bradysia sp. nr. coprophila, Diptera: Sciaridae), and no diseases (especially Xanthomonas axonopodis and Phytophthora nicotianae). Different treatments resulted in changes on macro and micronutrients content in shoots and roots, substrate, and FS at 0, 30, 60 and 90days (p< 0.0001). Higher FS concentrations increased the nutrient content over time (p < 0.0001). There was a decrease in pH and an increase in electric conductivity on treatments with higher VWC and FS (p < 0.0001). The substrate electric conductivity reached 5dSm−1 twice, demanding substrate washing by water application on treatments with VWC of 0.36 and 0.48m3 m−3 and FS of 75%. Subirrigation is suitable for liner production in 56-cm3 cone-shaped containers.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.06.017
      Issue No: Vol. 192 (2017)
       
  • Optimization of irrigation scheduling for spring wheat with mulching and
           limited irrigation water in an arid climate
    • Authors: Yeqiang Wen; Songhao Shang; Jian Yang
      Pages: 33 - 44
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Yeqiang Wen, Songhao Shang, Jian Yang
      Combining mulch and irrigation scheduling may lead to an increase of crop yield and water use efficiency (WUE=crop yield/evapotranspiration) with limited irrigation water, especially in arid regions. Based on 2 years’ field experiments with ten irrigation-mulching treatments of spring wheat (Triticum aestivum L.) in the Shiyang River Basin Experiment Station in Gansu Province of Northwest China, a simulation-based optimization model for deficit irrigation scheduling of plastic mulching spring wheat was used to analyze optimal irrigation scheduling for different deficit irrigation scenarios. Results revealed that mulching may increase maximum grain yield without water stress by 0.4–0.6tha−1 in different years and WUE by 0.2–0.3kgm−3 for different irrigation amounts compared with no mulching. Yield of plastic mulching spring wheat was more sensitive to water stress in the early and development growth stages with an increase of cumulative crop water sensitive index (CCWSI) by 42%, and less sensitive to water stress in the mid and late growth stages with a reduction of CCWSI by 24%. For a relative wet year, when irrigation water is only applied once, it should be at the mid to end of booting growth stage. Two irrigations should be applied at the beginning of booting and heading growth stages. The irrigation date can be extended to the beginning of jointing and grain formation growth stages with more water available for irrigation. For a normal or a dry year, the first irrigation should be applied 5–8days earlier than the wet year. The highest WUE of 3.6kgm−3 was achieved with 180mm of irrigation applied twice for mulching in a wet year. Combining mulch and optimal deficit irrigation scheduling is an effective way to increase crop yield and WUE in arid regions.
      Graphical abstract image

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.06.023
      Issue No: Vol. 192 (2017)
       
  • Automated ebb-and-flow subirrigation for citrus liners production. I.
           Plant growth
    • Authors: Rhuanito Soranz Ferrarezi; Roberto Testezlaf
      Pages: 45 - 57
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Rhuanito Soranz Ferrarezi, Roberto Testezlaf
      Ebb-and-flow subirrigation is a closed system that applies water to the bottom of the containers, reducing water and nutrient losses due to recirculation of fertilizer solution (FS). The technology can improve plant growth and eliminate the improper disposal of salts into the environment. Subirrigation is widely used in the ornamental industry, and sensor-based ebb-and-flow benches can be used by the citrus nursery industry. There is a need for establishing water and fertilizer guidelines to produce citrus rootstocks. The objectives of this study were: 1) design and build an ebb-and-flow subirrigation equipment, 2) automate the system operation using soil moisture sensors, 3) evaluate the system performance on plant growth, and 4) determine the water and fertilizer guidelines to produce Rangpur lime (Citrus × limonia) liners in 56-cm3 cone-shaped containers. The treatments were four volumetric water content (VWC) to trigger subirrigation (0.12, 0.24, 0.36 and 0.48m3 m−3), three FS concentrations (25%, 50% and 75% of the fertilizer recommendation) and a control (nursery manual overhead irrigation using breaker nozzles), arranged in a completely randomized 4×3+1 factorial plus design, with three replications. The system was automated by 39 capacitance sensors connected to a data logger, multiplexer and relay drivers, which controlled independent submersible pumps. Subirrigation was turned on when VWC dropped below the set thresholds. Sensors effectively monitored the substrate moisture and controlled subirrigation. Treatments with highest VWC had higher substrate moisture and number of irrigations over time (p< 0.0001). The volume of water applied doubled from treatments 0.12–0.48m3 m−3 (p< 0.0001). Subirrigation increased shoot height, stem diameter, dry weight, leaf area, physiological parameters (leaf intracellular concentration of CO2, transpiration, stomatal conductance, and net photosynthesis), and water use efficiency in response to increase in VWC and FS (p< 0.0001). Subirrigation shortened the crop cycle in 30 days, anticipating the liners transplant for grafting, allowing another cultivation cycle in the nursery during the year. VWC of 0.48m3 m−3 and FS concentration of 50% of the recommended value for overhead irrigation are indicated for Rangpur lime liner production in 56-cm3 containers.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.06.016
      Issue No: Vol. 192 (2017)
       
  • Effects of water table management and row width on the growth and yield of
           three soybean cultivars in southwestern Japan
    • Authors: Naoki Matsuo; Masakazu Takahashi; Tetsuya Yamada; Motoki Takahashi; Makita Hajika; Koichiro Fukami; Shinori Tsuchiya
      Pages: 85 - 97
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Naoki Matsuo, Masakazu Takahashi, Tetsuya Yamada, Motoki Takahashi, Makita Hajika, Koichiro Fukami, Shinori Tsuchiya
      In southwestern Japan, soil water fluctuations from flooding to drought cause unstable soybean yields. Water table management (WTM) with sub-irrigation/drainage systems will overcome the soybean yield instability by inhibiting these fluctuations. Narrow row cultivation is expected to increase soybean yields. The effects of WTM and row width on soybean growth and yield in this region are not clear. We evaluated the effects of WTM with sub-irrigation/drainage systems and row widths (35 or 70cm) on the growth and yield of one conventional (tall main stem) and two newly developed (short main stem) soybean cultivars. The WTM consisted of (1) fluctuation of the water table between the natural water table depth and that at 30cm depth according to the growth stage and weather conditions, especially rainfall events (newly developed); (2) maintaining the water table at a 30cm constant depth throughout the growth period (recommended in Japan); and (3) the natural water table with an underdrain (control). No significant interaction was observed between the WTM and cultivar or row width treatment, indicating that cultivars and row width treatments responded similarly to WTM. WTM 1 and 2 decreased the soybean yield by approx. 5% when the natural water table depth in control existed at 50–60cm depths throughout the growing period, indicating that the natural water table depth in control was near optimum for soybean growth and yield. Before performing WTM, therefore, the natural water table depth should be measured and considered. The combination of newly developed cultivars with narrow rows had similar or greater yields than conventional cultivation (cultivar and row width), due mainly to an increase in pods m−2 and a decrease in yield loss without severe lodging. Thus, yield potential in southwestern Japan could be increased by narrow row cultivation, but cultivars with short main stem lengths should be cultivated.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.06.024
      Issue No: Vol. 192 (2017)
       
  • Modelling of E. coli inactivation by chlorine dioxide in irrigation water
    • Authors: Francisco López-Gálvez; Imca Sampers; María I. Gil; Ana Allende
      Pages: 98 - 102
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Francisco López-Gálvez, Imca Sampers, María I. Gil, Ana Allende
      Irrigation water has been highlighted as a potential contamination source of fresh produce with foodborne pathogens. Water disinfection treatments can be used to improve its microbiological safety. Growers should ascertain the minimum effective disinfectant doses able to achieve the desired microbiological goals. Furthermore, potential unwanted effects both on crop health and on chemical risks associated with the accumulation of disinfection by-products (DBPs) on the crop must be taken into account. The minimum effective doses vary depending on intrinsic factors (e.g. physicochemical characteristics of the irrigation water, concentration of the target microorganism) and also extrinsic factors (e.g. geographical and weather conditions). In the present study, different types of surface irrigation water were treated with various doses of a stable solution of chlorine dioxide (ClO2) (0.1–2.5mg/L) at 21±2°C for a contact time of 1min. Escherichia coli concentration (before and after treatment) and the residual ClO2 (after treatment) were analyzed. Several water physicochemical parameters were measured (chemical oxygen demand (COD), turbidity, pH, oxidation-reduction potential (ORP), conductivity and absorbance of filtered water samples at 254nm (UV254)). Data obtained was used to develop a model for ClO2 decay and a model for E. coli inactivation by linear regression. The ClO2 decay model (adjusted R2 =0.93) included the initial ClO2 concentration and the UV254 as explanatory variables. The E. coli inactivation model (adjusted R2 =0.77) included the initial ClO2 concentration, the initial E. coli concentration, and the UV254 as explanatory variables. The development of these models would help growers in making decisions regarding the minimum effective doses they might use to treat their irrigation water when using a stable solution of ClO2 to reduce microbial risk of fresh produce.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.07.001
      Issue No: Vol. 192 (2017)
       
  • Application of AnnAGNPS to model an agricultural watershed in East-Central
           Mississippi for the evaluation of an on-farm water storage (OFWS) system
    • Authors: Ritesh Karki; Mary Love M. Tagert; Joel O. Paz; Ronald L. Bingner
      Pages: 103 - 114
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Ritesh Karki, Mary Love M. Tagert, Joel O. Paz, Ronald L. Bingner
      Annualized Agricultural Non-Point Source Pollutant Model (AnnAGNPS) is a watershed-scale, continuous simulation, physical model that has been widely used to simulate runoff, nutrients, sediment, and pesticides in different watersheds. This study applied AnnAGNPS to simulate runoff, nutrients (total Nitrogen and total Phosphorus), and sediment from an agricultural watershed of 30.3ha in East-Central Mississippi. AnnAGNPS was then used to evaluate an On-Farm Water Storage (OFWS) system as a Best Management Practice (BMP) for nutrient and sediment loading control from agricultural fields within this watershed and as a source of water for irrigation. An R2 of 0.85 and E of 0.82 in daily runoff estimation showed that the model can adequately simulate runoff from watersheds in East-Central Mississippi. In addition, an R2 of 0.88 and E of 0.67 for event-based sediment estimation and an R2 of 0.74 and E of 0.54 for monthly phosphorus estimation also showed that the model can satisfactorily simulate sediment and phosphorus. However, the model was not able to simulate nitrogen at a monthly scale, with an R2 of only 0.15 and E of −0.107, because of the lack of site specific and accurate input data. After AnnAGNPS successfully simulated runoff, sediment, and phosphorus, an evaluation of the OFWS system showed that the system was able to capture 220,000m3 of runoff from the monitored watershed that can be stored and used for irrigation. AnnAGNPS estimated that the OFWS system also captured 46 tons of sediment and 558kg of phosphorus during the monitoring period, preventing downstream nutrient and sediment pollution.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.07.002
      Issue No: Vol. 192 (2017)
       
  • Field soil and ditch sediment phosphorus dynamics from two artificially
           drained fields on poorly drained soils
    • Authors: K. Daly; P. Tuohy; D. Peyton; D.P. Wall; O. Fenton
      Pages: 115 - 125
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): K. Daly, P. Tuohy, D. Peyton, D.P. Wall, O. Fenton
      The installation of artificial drains alters soil permeability such that migrating water interacts with soil and sediment biogeochemistry to mobilise or attenuate phosphorus (P). Soil and ditch sediment P chemistry was explored at two artificially drained sites with similar land use, management and drainage class. Site A was characterised by high total P content (282–1437mgkg−1) and elevated water soluble P (WSP) (10.11mgkg−1) in a Humic topsoil. Subsurface horizons contained high amounts of leached aluminium (Al) and iron (Fe) and P sorption capacities expressed by the Freundlich K term increased with depth from 338 to 942mgkg−1. Site B was characterised by low TP (58–476mgkg−1) and low P sorption capacities (40–173mgkg−1) that decreased with depth, owing to a high% sand and low Al. Bankside and sediment in the ditch were mostly higher or comparable to P sorption properties measured in subsurface soil horizons from adjacent fields. Dissolved reactive P (DRP) concentrations were monitored in the open ditch, end-of-pipe and in-field piezometers and highest values were recorded in the open ditch (0.03–0.183mgl−1) at Site A, potentially due to diffuse and point sources on the farm. Higher P concentrations were recorded at end-of-pipe locations compared to piezometers at similar depth, and attributed to a larger contributing area reaching the pipe from the surface and surrounding subsurface layers. Attenuation of WSP by subsoil at Site A was evidenced by low piezometer values (0–0.003mgl−1). Low P sorption in the ditch at Site B suggests that dredging could expose low P sorbing layers, but adding topsoil could enhance P sorption. Drainage design, maintenance, and measures for P mitigation require an assessment of surface and subsurface P dynamics to ensure a ‘right measure right place’ approach.
      Graphical abstract image

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.07.005
      Issue No: Vol. 192 (2017)
       
  • Impact of a two-stage ditch on channel water quality
    • Authors: Andi Hodaj; Laura C. Bowling; Jane R. Frankenberger; Indrajeet Chaubey
      Pages: 126 - 137
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Andi Hodaj, Laura C. Bowling, Jane R. Frankenberger, Indrajeet Chaubey
      A two-stage ditch involves modifications of a conventional, trapezoidal drainage ditch to better replicate the features of a natural stream through the addition of adjacent floodplains or benches. Previous research in Indiana and Ohio has shown that two-stage ditches offer the potential to reduce sediment load and extend the interaction time between water, bench vegetation, and bench soil allowing larger uptake of nutrients by the vegetation and increasing the denitrification rates. A two-stage ditch was constructed that drains an area of approximately 267ha of farmland used for corn and soybean production. Discharge, nitrate-N (NO3), total phosphorus (TP), soluble reactive phosphorus (SRP) and total suspended sediment (TSS) were monitored in the two-stage ditch and a control reach immediately upstream. The two-stage ditch was found to significantly decrease TP, SRP and TSS concentrations and loads. Although the two-stage ditch decreased NO3 concentrations significantly, it did not have a significant impact on NO3 loads. More specifically, the two-stage ditch reduced the loads of TP by 40%, SRP by 11% and TSS by 22–40% depending on the stage of vegetation establishment on its floodplain benches, compared to an increase in load of 78%, 2% and 1%, respectively in the control reach.

      PubDate: 2017-07-28T01:31:22Z
      DOI: 10.1016/j.agwat.2017.07.006
      Issue No: Vol. 192 (2017)
       
  • Evaluation of soil water percolation under different irrigation practices,
           antecedent moisture and groundwater depths in paddy fields
    • Authors: Baoli Xu; Dongguo Shao; Xuezhi Tan; Xia Yang; Wenquan Gu; Haoxin Li
      Pages: 149 - 158
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Baoli Xu, Dongguo Shao, Xuezhi Tan, Xia Yang, Wenquan Gu, Haoxin Li
      Understanding soil water percolation in paddy fields is helpful to optimize irrigation schedule for rice production and improve water use efficiency under various irrigation practices and groundwater depths. Calibrated HYDRUS-1D model was used to simulate soil water movement and water balance in this study. We conducted scenario analyses based on the model to evaluate the combined effects of irrigation amount in an irrigation event (irrigation amount), irrigation duration, antecedent soil moisture, and groundwater depth on deep percolation (DP) in paddy fields. Results showed that during an irrigation event, there would be higher DP in paddy fields with higher antecedent soil moisture (≥−10kPa), larger irrigation amount (7cm) and/or free drainage in the bottom of rice root zones. We also used a classification and regression tree model to analyze the relative contribution of different factors to DP. Results indicated that antecedent soil moisture was the primary factor that contributed 46.3% of DP variation. Groundwater depth contributed 32.5% of DP variation, while irrigation amount (18.7%) and irrigation duration (2.5%) contributed least for DP variation. Furthermore, effects of these factors on DP interacted with each other. In scenario analysis, the contribution of antecedent soil moisture increased from 16.1% to 65.2% as the groundwater depth increased. When irrigation amount rose from 1cm to 5cm, the contributions of antecedent soil moisture increased to 77.6% from 57.1%; when irrigation amount was 7cm, the contributions of antecedent soil moisture decreased to 46.4%. The contribution of irrigation amount rose to 55.7% from 28.4% with the increase of antecedent soil moisture, while the contributions of groundwater depth to DP showed opposite variation to irrigation amount as antecedent soil moisture altered. Based on relative contribution of these factors, optimal combinations of irrigation practices, antecedent soil moisture and groundwater depth were screened out to control DP for promoting rice growth and improving water use efficiency.

      PubDate: 2017-07-28T01:31:22Z
      DOI: 10.1016/j.agwat.2017.06.002
      Issue No: Vol. 192 (2017)
       
  • Dissolved organic carbon loading from the field to watershed scale in
           tile-drained landscapes
    • Authors: Mark R. Williams; Kevin W. King; Norman R. Fausey
      Pages: 159 - 169
      Abstract: Publication date: October 2017
      Source:Agricultural Water Management, Volume 192
      Author(s): Mark R. Williams, Kevin W. King, Norman R. Fausey
      Subsurface tile drains influence watershed fluxes of nitrogen, phosphorus, and pesticides, but few studies have examined the role of subsurface tile drains and drainage water management practices on watershed dissolved organic carbon (DOC) export. The objective of this study was therefore to quantify the contribution of subsurface tile drains to watershed DOC export and to evaluate the effect of drainage water management of DOC concentrations and loads in tile-drained fields. Discharge and DOC concentration were measured at the outlet of an agricultural headwater watershed (3.9km2) in Ohio, USA and all of the subsurface tile drains (6 total) within the watershed over an 8-year period. Results showed that DOC concentration in both subsurface tile drains and stream water were highly variable (0.1–44.4mgL−1), with mean DOC concentrations ranging from 5.7 to 8.2mgL−1. Intra-annual variability in subsurface tile drain and watershed hydrology yielded seasonal differences in DOC loading. Over the study period, 81.7% and 92.4% of watershed and subsurface tile drain DOC loading, respectively, occurred during 20% of the time, typically during winter and spring high flow events. Mean annual DOC loading from the drainage network was 19.6kgha−1, while mean annual DOC loading at the watershed outlet was 43.9kgha−1. On average, subsurface tile drainage comprised 33% of monthly watershed DOC export (<1–82%). Implementing drainage water management at one of the subsurface tile drains decreased discharge (179mm; 22%) and DOC loading (6.8kgha−1; 26%) compared to an adjacent free draining subsurface tile drain. Findings from this study demonstrate the utility of simultaneously monitoring solute fluxes from both field and watershed scales, and indicate that subsurface tile drains are a significant source of DOC to headwater agricultural streams. Further, results suggest that drainage water management can significantly decrease DOC losses from tile-drained fields.

      PubDate: 2017-07-28T01:31:22Z
      DOI: 10.1016/j.agwat.2017.07.008
      Issue No: Vol. 192 (2017)
       
  • Combining the ensemble mean and bias correction approaches to reduce the
           uncertainty in hillslope-scale soil moisture simulation
    • Authors: Kaihua Liao; Xiaoming Lai; Zhiwen Zhou; Qing Zhu
      Pages: 29 - 36
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Kaihua Liao, Xiaoming Lai, Zhiwen Zhou, Qing Zhu
      The ROSETTA model has routinely been applied to predict the soil hydraulic properties for simulating the water flow at the hillslope scale. However, the uncertainties in water flow simulations are substantial due to the soil heterogeneity and ROSETTA model structure. In order to reduce these uncertainties, this study used the HYDRUS-2D and ensemble mean to simulate soil moisture based on the outputs of all candidate models. In addition, the bias correction techniques (including linear bias correction (LBC) and cumulative distribution function (CDF) matching) were also applied to improve the prediction of soil moisture. A total of 320days of observed soil moisture data at two depths (10 and 30cm) in the upper and lower slope positions were adopted to evaluate the performances of different bias correction methods results showed that the uncertainty in hillslope-scale soil moisture simulation due to the ROSETTA model structure was more important than that due to the soil heterogeneity. The CDF matching-based nonlinear bias correction approach was generally better than the LBC in reducing the uncertainty in soil moisture simulation. Combining the ensemble mean and CDF matching was a viable approach to improve the accuracy of the numerical model for simulating the hillslope-scale soil moisture variations.

      PubDate: 2017-06-10T06:59:46Z
      DOI: 10.1016/j.agwat.2017.05.014
      Issue No: Vol. 191 (2017)
       
  • Are basin and reservoir tillage effective techniques to reduce runoff
           under sprinkler irrigation in Mediterranean conditions'
    • Authors: Luis L. Silva
      Pages: 50 - 56
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Luis L. Silva
      The increasing use of low pressure moving sprinklers irrigation systems, like center-pivot irrigation systems, has increased surface runoff problems. Runoff decreases the irrigation system application efficiency, increasing the operational costs. It can also be responsible for environmental problems, such as soil erosion and the contamination of surface waters. Basin tillage and reservoir tillage have proved to be an effective practice to prevent runoff in many situations and can be an option to reduce surface runoff under moving sprinkler irrigation systems operating in Mediterranean conditions. However, even though it is a common practice in some Mediterranean regions, there are very few studies quantifying the effect of these tillage practices under moving sprinkler irrigation systems in Mediterranean countries. Many farmers are still not convinced that this is the best practice to prevent runoff. Some of them are converting to conservation agriculture, using no-till or minimum tillage, but the results of these tillage systems in the prevention of runoff are not always consistent. The industry is also creating new implements used to create the basins and reservoirs that apparently have some advantages over the old ones. But more studies are still required in order to be able to identify the better solutions for different soil, crop and irrigation management situations.

      PubDate: 2017-06-15T07:25:18Z
      DOI: 10.1016/j.agwat.2017.06.003
      Issue No: Vol. 191 (2017)
       
  • Does water salinity affect pepper plant response to nitrogen
           fertigation'
    • Authors: Hagai Yasuor; Guy Tamir; Avraham Stein; Shabtai Cohen; Asher Bar-Tal; Alon Ben-Gal; Uri Yermiyahu
      Pages: 57 - 66
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Hagai Yasuor, Guy Tamir, Avraham Stein, Shabtai Cohen, Asher Bar-Tal, Alon Ben-Gal, Uri Yermiyahu
      Recent increase in demand for agricultural products combined with scarcity of fresh water has motivated increased use of non-conventional water sources for irrigation. Application of water varying in quality dictates adjustment of nitrogen (N) management. The response of bell pepper to a range of different concentrations of N and salinity (NaCl) was evaluated in soilless and field experiments under greenhouse conditions. Pepper plant biomass and yield increased with N and decreased with salinity. Chloride accumulated mainly in the stems and the fraction of Cl in leaves increased as a function of increased exposure to salinity. Increasing N application resulted in reduced Cl uptake and accumulation in pepper organs, including leaves and petioles. Although N significantly reduced Cl content and concentration in leaves and petioles it did not compensate for the negative effects of increasing salinity. This indicates that salinity itself and not Cl − N competition was the limiting factor affecting growth and yield.

      PubDate: 2017-06-20T04:54:12Z
      DOI: 10.1016/j.agwat.2017.05.012
      Issue No: Vol. 191 (2017)
       
  • Impact of irrigation and nitrogen fertilizer rate on soil water trends and
           maize evapotranspiration during the vegetative and reproductive periods
    • Authors: D.R. Rudnick; S. Irmak; K. Djaman; V. Sharma
      Pages: 77 - 84
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): D.R. Rudnick, S. Irmak, K. Djaman, V. Sharma
      Field research was conducted in 2011 and 2012 at the University of Nebraska-Lincoln South Central Agricultural Laboratory located near Clay Center, NE to evaluate maize actual evapotranspiration (ETa) during the vegetative and reproductive growth periods for 0, 84, 140, 196, and 252kgha−1 nitrogen (N) fertilizer treatments under full irrigation (FIT), limited irrigation (75% of FIT), and rainfed settings. Daily ETa values were greatest during the early reproductive period (silking to blister growth stages) with average values of 3.62, 5.18, and 5.91mmd−1 in 2011 and 4.37, 5.92, and 6.12mmd−1 in 2012 for rainfed, 75% FIT, and FIT, respectively. Maize ETa during the vegetative period was not significantly impacted by N fertilizer rate in 2011 (P0.05 = 0.2357) or 2012 (P0.05 = 0.6341). Whereas, reproductive period ETa for FIT and 75% FIT for the pooled years significantly increased with N fertilizer rate with slopes of 0.20 and 0.17, respectively. The rainfed regression slopes were not statistically different from zero in 2012 (P0.05 = 0.1467) or pooled years (P0.05 = 0.0505). The increase in reproductive ETa with N fertilizer and irrigation resulted in a positive grain yield response with slopes of 0.021, 0.048, and 0.104 Mg ha−1 mm−1 for the rainfed, 75% FIT, and FIT settings, respectively.

      PubDate: 2017-06-20T04:54:12Z
      DOI: 10.1016/j.agwat.2017.06.007
      Issue No: Vol. 191 (2017)
       
  • An interval multistage classified model for regional inter- and
           intra-seasonal water management under uncertain and nonstationary
           condition
    • Authors: Shu Chen; Dongguo Shao; Xuezhi Tan; Wenquan Gu; Caixiu Lei
      Pages: 98 - 112
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Shu Chen, Dongguo Shao, Xuezhi Tan, Wenquan Gu, Caixiu Lei
      In regional water management, various uncertainties such as randomness, non-stationarities, dynamics and complexities, lead to difficulties for water managers. To deal with the above problems, a new methodology is proposed by introducing two methods nonstationary analysis, where the generalized additive model is selected to analyze and fit the distribution of water inflow; and model optimization, where an interval multistage water classified-allocation model (IMWCA) is formulated to optimally allocate the available water. By incorporating multistage stochastic programming, interval parameter programming and classification thought, the IMWCA model can tackle both stochastic and imprecise uncertainties, realize inter-seasonal dynamic allocation, and address the complexity of various water users. The methodology is applied to the Zhanghe Irrigation District to optimize water allocation for municipality, industry, hydropower and agriculture among winter, spring, summer and autumn. The Zhanghe Reservoir seasonal inflow is found to be nonstationary for all the seasons and can be well fitted by the corresponding distributions, showing the sense of nonstationary analysis. Additionally, the comparison with the other model demonstrates the need for classification. From the results, municipality and industry are more competitive than hydropower. The Dongbao, Dangyang and Zhanghe districts have a higher priority than the Jingzhou and Shayang districts for irrigation water. Water requirements are more likely to be satisfied in autumn. These solutions of optimal targets and optimal water allocation are valuable for optimizing inter- and intra-seasonal water resource allocation under uncertainty.

      PubDate: 2017-06-27T09:01:35Z
      DOI: 10.1016/j.agwat.2017.06.005
      Issue No: Vol. 191 (2017)
       
  • Combined deficit irrigation and soil fertility management on different
           soil textures to improve wheat yield in drought-prone Bangladesh
    • Authors: S.M.T. Mustafa; E. Vanuytrecht; M. Huysmans
      Pages: 124 - 137
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): S.M.T. Mustafa, E. Vanuytrecht, M. Huysmans
      Proper utilization of water resources is very important in agro-based and drought-prone Bangladesh. Sustainable use of water resources in agriculture requires irrigation schedules based on local environmental conditions, soil type and water availability. In this study, the water productivity model AquaCrop was used to simulate different water and fertilizer management strategies in a drought prone area of Bangladesh to obtain management recommendations. First, the Standardised Precipitation Index (SPI) and Reconnaissance Drought Index (RDI) were determined to quantify the aggregated deficit between precipitation and the evaporative demand of the atmosphere, which confirm that meteorological drought is occurring frequently in the study area. Also, the AquaCrop model was successfully calibrated and validated for wheat in the area, which was confirmed by the several statistical indicators, and could be used to design water and fertilizer management strategies. Simulations identified stem elongation (jointing) to booting and flowering stage as the most water sensitive stages for wheat. Deficit irrigation during the most water sensitive stages could increase the interannual yield stability and the grain yield compared to rainfed conditions for different soil fertility levels on loamy and sandy soils by 21–136% and 11–71%, respectively, while it could increase water productivity compared to full irrigation strategies. Deficit irrigation resulted in grain yields almost equal to yields under full irrigation and could at the same time save 121–197mm of water per growing season. Specifically, we suggest two irrigation applications: one at the stem elongation (jointing) to booting stage and another at the flowering stage for loamy soils; and one at the end of seedling development to the beginning of crown root initiation stage and another at the flowering stage for sandy soils. Given the water scarcity in the region, instead of optimal fertility levels, moderate fertility levels are recommended that result in 60% of the potential biomass production for loamy soils and in 50% for sandy soils in combination with the suggested deficit irrigation strategies.

      PubDate: 2017-06-27T09:01:35Z
      DOI: 10.1016/j.agwat.2017.06.011
      Issue No: Vol. 191 (2017)
       
  • Three years of monitoring evapotranspiration components and crop and
           stress coefficients in a deficit irrigated intensive olive orchard
    • Authors: Nuno Conceição; Luca Tezza; Melanie Häusler; Sónia Lourenço; Carlos A. Pacheco; M. Isabel Ferreira
      Pages: 138 - 152
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Nuno Conceição, Luca Tezza, Melanie Häusler, Sónia Lourenço, Carlos A. Pacheco, M. Isabel Ferreira
      A long-term experiment was conducted to study water use of olive trees in a six-year-old, deficit irrigated, intensive olive orchard (‘Arbequina’) in one of the driest regions of Southern Portugal. Woody agricultural crops are regularly cultivated with some water stress to maintain an equilibrium between the vegetative and reproductive cycles, to improve production quality and, when irrigated, to save water. To achieve a precise irrigation scheduling it is necessary to quantify water use reduction due to water stress. This study reports results from spring 2010 to autumn 2012, and encompasses a hydrological drought occurred in 2012. A long-term seasonal time series of transpiration (Tr), was obtained by combining data on evapotranspiration (ET) measured with the eddy covariance method, soil evaporation measured with microlysimeters and sap flow measured with a heat dissipation method. For the years 2010 and 2011, with normal precipitation, Tr varied between 2 and 4mm/day, in the summer. In 2012, due to the winter drought, soil water content did not reach field capacity during the wet season and an important reduction in Tr was observed ranging from 1 to 2mm/day during summer. Predawn leaf water potential (Ψpd) was selected as plant water status indicator, because these olive trees showed near-isohydric behaviour. A function relating Ψpd to the correspondent stress coefficient (Ks) was used to decompose Tr/ETo into the basal crop coefficient (Kcb) and the Ks. The first, during the summer period, oscillated around 0.4 for years with precipitation close to average, while Ks estimated from Ψpd decreased between 1.0 in early June to about 0.83 before first autumn rain. However, these Ks values did not explain the important reduction observed in Tr during the 2012 severe drought. Measured Kcb values were compared to the ones modelled using approaches based on density factor. The derived Kcb values for summer were lower than those observed.

      PubDate: 2017-07-21T01:26:39Z
      DOI: 10.1016/j.agwat.2017.05.011
      Issue No: Vol. 191 (2017)
       
  • Design of concave and convex paired sloped drip laterals
    • Authors: Giorgio Baiamonte
      Pages: 173 - 183
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Giorgio Baiamonte
      Properly designed microirrigation plants allow water use efficiency to be optimized and quite high values of emission uniformity to be obtained in the field. Disposing paired laterals so that two distribution pipes extend in opposite directions from a common manifold contributes to provide more uniform pressure to all laterals in thesystem. Towards this end, an analytical procedure to optimize the uniform pressure when designing paired drip laterals on uniform slopes has recently been proposed, based on the assumption that the variations of the emitters’ flow rate along the lateral and the local losses due to the emitters’ insertions could be neglected. More recently, an easy method to fix the best position of the manifold (BMP) equal to 24% of the optimal lateral length was introduced. The mentioned procedures are valid under the assumption that the paired laterals are laid on straight slopes; however, real microirrigation units rarely follow an even gradient, whose topography is characterized by equally spaced contour lines. The objective of this study was to extend the analytical procedure to optimally design paired sloped drip laterals to the case in which the shape of the field is concave or convex. Results showed that the position where the minimum occurs in the downhill laterals and the optimal pressure head distribution lines vary with the shape of the drip lateral and that the easy method to fix the BMP=24% cannot be applied for paired sloped laterals laid on complex topography. Accordingly, a BMP relationship as a function of the curvature parameter of the lateral profile is proposed. Moreover, it is demonstrated that the optimal length of the paired lateral has achieved its minimum value, for a particular concave shape, at what corresponds to a paired lateral length 6.6% lower than that for straight paired laterals. By varying the curvature parameter, and for an inside diameter value equal to 17.6mm, some practical solutions are presented. The proposed procedure was successfully compared with that derived by the step-by-step exact procedure.

      PubDate: 2017-06-27T09:01:35Z
      DOI: 10.1016/j.agwat.2017.06.015
      Issue No: Vol. 191 (2017)
       
  • Alfalfa forage production under solid-set sprinkler irrigation in a
           semiarid climate
    • Authors: Jose Cavero; Jose M. Faci; Eva T. Medina; Antonio Martínez-Cob
      Pages: 184 - 192
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Jose Cavero, Jose M. Faci, Eva T. Medina, Antonio Martínez-Cob
      Under sprinkler irrigation, local environmental conditions have an important influence on irrigation water losses, plant physiological changes and uniformity of irrigation, leading to different crop water production functions. We studied during three years the effect of irrigation depth on the plant growth, forage yield and N content, evapotranspiration and water use efficiency of an alfalfa (Medicago sativa L.) crop irrigated with a commercial solid-set sprinkler system in a semiarid Mediterranean climate. Six irrigation treatments were tested: 55%, 75%, 85%, 100%, 115% and 130% of the theoretical crop irrigation requirement (CIRt), calculated without considering water losses or non-uniformity. The seasonal irrigation amount applied at the 100% of CIRt ranged from 598 to 786mm. The intercepted photosynthetically active radiation increased as the irrigation applied increased until the 115% of CIRt. Plant height at harvest linearly increased as the irrigation applied increased until the 130% of CIRt in two years. The maximum alfalfa forage yield was lower the first year (17Mgha−1) than in the two following years (20–22Mgha−1). The alfalfa forage yield increased linearly as the irrigation applied increased the first year of the experiment, but in the following two years this increase occurred until the irrigation applied was 115% of CIRt. The N content of alfalfa linearly decreased as the irrigation applied increased. The relationship between alfalfa forage yield and evapotranspiration was linear until the 115% of CIRt all years. The WUE of alfalfa was lower the first year of the experiment and was not affected by the irrigation applied in the rainiest year, but linearly increased as the irrigation applied increased up to 115% of CIRt in the other two years. Considering yield and quality (N content) of alfalfa forage and WUE, sprinkler irrigation with a solid-set system must be increased by 15% over the CIRt to optimize alfalfa forage production under the climatic conditions of the Ebro valley.

      PubDate: 2017-07-08T03:49:10Z
      DOI: 10.1016/j.agwat.2017.06.018
      Issue No: Vol. 191 (2017)
       
  • Energy balance and partitioning in partial plastic mulched and non-mulched
           maize fields on the Loess Plateau of China
    • Authors: Yu Feng; Daozhi Gong; Xurong Mei; Weiping Hao; Dahua Tang; Ningbo Cui
      Pages: 193 - 206
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Yu Feng, Daozhi Gong, Xurong Mei, Weiping Hao, Dahua Tang, Ningbo Cui
      Energy and water exchange processes between the land surface and atmosphere drive photosynthesis, evapotranspiration, sensible heat flux, energy storage in vegetation, and heating of the soil. Thus, understanding of energy exchange and partitioning is of importance for crop model development and water use efficiency improvement in raifed agro-ecosystems. The present study investigated the energy exchange and partitioning over rainfed maize croplands under two cultivation methods—conventional flat planting without mulching (CK) and a furrow-ridge system with plastic film partially mulching (MFR) for two growing seasons through synchronous measurements of eddy covariance system with multi micro-lysimeters on the eastern Loess Plateau of China, the effects of rainfall on the energy partitioning were also discussed. The results indicated that average energy balance closure were 0.89 and 0.84 for CK and MFR at half-hourly, 0.91 and 0.93 at daily interval, respectively. Each energy flux component presented typical diurnal variations during the entire growing stage, which was a single-peak curve. Latent heat flux (LE) showed typical seasonal variation that it increased during May to June, and reach a high value in July, then decreased gradually. However, compared to LE, sensible heat flux (H) and Bowen ratio showed a similar opposite trends, LE became the main consumer of available energy after maize plants grown quickly. LE of spring maize was the main component of net radiation (Rn), followed by H and soil heat flux (G), which accounted for 64.3%, 28.6%, and −0.2% for CK and 68.5%, 29.7%, and 0.1% for MFR in 2011, 56.8%, 20.1%, and 2.8% for CK and 58.0%, 25.5%, and 8.6% for MFR in 2012, respectively. Transpiration was the main component of LE, which accounted for 54.3%–76.6% of LE for the both treatments. Compared to the energy fluxes before rainfall, LE increased significantly while H and G decreased after rainfall in development stage, however in late stage, the changes in soil water content resulted by rainfall didn’t increase LE significantly for the both treatments due to the high canopy cover and senescent maize plants.

      PubDate: 2017-07-08T03:49:10Z
      DOI: 10.1016/j.agwat.2017.06.009
      Issue No: Vol. 191 (2017)
       
  • Prosper, survive or exit: Contrasted fortunes of farmers in the
           groundwater economy in the Saiss plain (Morocco)
    • Authors: Fatah Ameur; Marcel Kuper; Caroline Lejars; Patrick Dugué
      Pages: 207 - 217
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Fatah Ameur, Marcel Kuper, Caroline Lejars, Patrick Dugué
      In North Africa, the development of groundwater-based irrigation enabled agricultural intensification and market-oriented production. Groundwater use was also often said to alleviate smallholder poverty. However, there is growing evidence linking the expansion of groundwater-based agriculture with increasing socioeconomic inequalities in a context of declining water tables and rapid agrarian change. This paper analyzes the contrasted fortunes of different categories of farmers participating in the groundwater economy, depending on access to other resources including land, capital and labor. The study was conducted in a 3910ha area in the Saiss plain (Morocco), where rapid agrarian transformations took place with the arrival of investors attracted by state subsidies and the possibility to carry out intensive groundwater-based agriculture. The study began with interviews with key informants to determine the role of groundwater use in farm trajectories. Then, an inventory was undertaken of all farms and of all wells and tube-wells in the study area. Next, the groundwater use per farm type was determined on a sample of 24 farms. Finally, the socioeconomic differentiation of farms was determined, based on the inequalities in access to groundwater, land, labor and financial capital. The results revealed contrasted fortunes of farmers involved in the groundwater economy. The boom in the groundwater economy benefitted entrepreneurial and well-endowed farmers who made intensive use of groundwater, while the effects of their overexploitation of groundwater fed the marginalization of family farmers. The results show that capital has replaced landownership as the dominant production factor, thereby re-qualifying what is a ‘small’ farmer. Capital is not only required to obtain access to groundwater, but also to deal with the more risky agriculture frequently conducted in the groundwater economy. This leads to the exclusion of small family farmers who may quit the groundwater economy poorer than they entered it. The urgent need to control access to and use of groundwater in the face of declining water tables has little chance of producing results if socioeconomic inequalities remain unaddressed.

      PubDate: 2017-07-08T03:49:10Z
      DOI: 10.1016/j.agwat.2017.06.014
      Issue No: Vol. 191 (2017)
       
  • A novel tool to assess available hydrological information and the
           occurrence of sub-optimal water allocation decisions in large irrigation
           districts
    • Authors: Alexander Kaune; Micha Werner; Erasmo Rodríguez; Poolad Karimi; Charlotte de Fraiture
      Pages: 229 - 238
      Abstract: Publication date: September 2017
      Source:Agricultural Water Management, Volume 191
      Author(s): Alexander Kaune, Micha Werner, Erasmo Rodríguez, Poolad Karimi, Charlotte de Fraiture
      Hydrological information on water availability and demand is vital for sound water allocation decisions in irrigation districts, particularly in times of water scarcity. However, water allocation decisions are often taken based on uncertain hydrological information, which may lead to sub-optimal decisions and agricultural production loss. This study aims to assess the availability of hydrological information in large irrigated areas (>250km2) and evaluate water allocation decisions being taken. An index tool that measures the level of availability of hydrological information in irrigation districts that is used in planning and operation was developed. The index is calculated based on a compound that considers the period of record, temporal and spatial resolution of the data. Contingency tables that compare the observed discharge in water extraction sites, supply in the main canals, and irrigation demand estimates, were generated allowing the rate of occurrence of sub-optimal water allocation decisions to be determined. Through this method, excellent index results were found for an irrigation district in Australia (Murrumbidgee district), while irrigation districts in Colombia (Coello district) and Costa Rica (DRAT district) showed fair to poor information availability, which correspond to a higher rate of occurrence of sub-optimal water allocation decisions. The results imply that the use of additional hydrological information is beneficial in reducing the rate of occurrence of sub-optimal water allocation decisions, ultimately contributing to higher crop yields.

      PubDate: 2017-07-08T03:49:10Z
      DOI: 10.1016/j.agwat.2017.06.013
      Issue No: Vol. 191 (2017)
       
  • Can ridge-furrow plastic mulching replace irrigation in dryland wheat and
           maize cropping systems?
    • Authors: Stefani Daryanto; Lixin Wang; Pierre-André Jacinthe
      Pages: 1 - 5
      Abstract: Publication date: August 2017
      Source:Agricultural Water Management, Volume 190
      Author(s): Stefani Daryanto, Lixin Wang, Pierre-André Jacinthe
      Dryland crop production requires significant water investments, but problems associated with irrigation have been observed in many dryland regions (e.g., China, Australia and the Mediterranean basin). A key strategy for maintaining crop yields without over-exploiting the scarce water resource is by increasing water use efficiency (WUE). Plastic mulching technology for wheat and maize has been commonly used in China, but their effect on yield, soil water content, evapotranspiration (ET), and WUE has not been compared with traditional irrigation. Using a meta-analysis approach, we quantitatively examined the efficacy of plastic mulching in comparison with traditional irrigation in the same region. By covering the ridges with plastic and channeling rainwater into a very narrow planting zone (furrow), our results showed that plastic mulching resulted in a yield increase comparable to irrigated crops but used 24% less water in comparison with irrigation due primarily to a much greater WUE and better retention of soil water. The higher WUE in plastic-mulched croplands was likely a result of a greater proportion of available water being used for transpiration (T) than evaporation (E). Currently production costs and residual plastic pollution hinder worldwide adoption of the technique, despite being a promising strategy for dryland cropping systems.

      PubDate: 2017-05-20T15:25:36Z
      DOI: 10.1016/j.agwat.2017.05.005
      Issue No: Vol. 190 (2017)
       
  • Signal intensity based on maximum daily stem shrinkage can reflect the
           water status of apple trees under alternate partial root-zone irrigation
    • Authors: Shaoqing Du; Ling Tong; Xiaotao Zhang; Shaozhong Kang; Taisheng Du; Sien Li; Risheng Ding
      Pages: 21 - 30
      Abstract: Publication date: August 2017
      Source:Agricultural Water Management, Volume 190
      Author(s): Shaoqing Du, Ling Tong, Xiaotao Zhang, Shaozhong Kang, Taisheng Du, Sien Li, Risheng Ding
      Signal intensity (SI) and maximum daily stem shrinkage (MDS) are indicators of the water status and irrigation schedule of fruit trees under conventional irrigation (CI). However, whether SI can reflect the water status of fruit trees under alternate partial root-zone irrigation (APRI) has rarely been reported. Field experiments were conducted on apple trees over two years with two irrigation methods (CI and APRI) and two irrigation amounts (400mm and 500mm) in an arid area. The followings were measured over the whole growth season: MDS, sap flow (SF), air temperature, net radiation, vapor pressure deficit, reference evapotranspiration, soil water content, midday stem water potential and predawn leaf water potential. The signal intensities based on MDS (SIMDS ) and sap flow (SISF ) were calculated. The results show: first, MDS was significantly higher under CI at 400mm than under APRI at 400mm, while no difference was found between the two irrigation methods at 500mm. MDS was significantly positively correlated with meteorological factors, while SIMDS and SISF were not. Second, SIMDS was significantly lower under APRI than under CI, while no difference was found in SISF between the two irrigation methods. Third, in contrast to SISF , SIMDS was significantly correlated with soil water content as well as with midday stem water potential and predawn leaf water potential under APRI. These results show that the signal intensity based on maximum daily stem shrinkage accurately indicates the water status of apple trees under alternate partial root-zone irrigation in an arid apple production area.

      PubDate: 2017-05-26T08:47:09Z
      DOI: 10.1016/j.agwat.2017.05.004
      Issue No: Vol. 190 (2017)
       
  • Olive mill wastewater as a source of organic matter, water and nutrients
           for restoration of degraded soils and for crops managed with sustainable
           systems
    • Authors: T. Chatzistathis; T. Koutsos
      Pages: 55 - 64
      Abstract: Publication date: August 2017
      Source:Agricultural Water Management, Volume 190
      Author(s): T. Chatzistathis, T. Koutsos
      Every year, worldwide olive oil production produces in a short period of time (late autumn-winter) vast quantities of olive mill wastewater (OMW). This product causes environmental and management problems due to its disposal into rivers and lakes. During the last years, OMW application (used either as crude, raw material, or as treated- with different methods- product, in order to decrease its phytotoxicity) was tested under field conditions as organic amendment; many times, the results with regard to the raise of plant growth, crop yields and enhancement of soil fertility were promising, while in some other cases phytotoxicity problems, groundwater contamination, decreased soil porosity, as well as enhanced electrical conductivity, salinity, increased soil acidity and decreased N mineralization rate occurred. On the other hand, OMW is a low-cost source of nutrients (especially N, P, K, Mg and Fe), water, and organic matter; thus, it can be successfully used for the restoration of degraded croplands, in hilly, eroded, poor in organic C, and/or semi-arid areas. Since one of the first steps in land restoration process is the enhancement of soil organic C, OMW is an excellent alternative solution for the: i) increase of organic matter, ii) improvement of soil physical properties, and iii) enhancement of productivity of degraded croplands. In addition, under certain conditions (use of treated, or diluted with water OMW in order to decrease phenol content, avoidance of exaggerate applications, suitable application rate(s) and season), OMW can be safely used as a soil amendment and low-cost organic fertilizer for crops, managed with sustainable systems. The basic purpose of this review was to present and thoroughly discuss all the beneficial aspects of OMW application with regard to: i) the restoration of degraded croplands, ii) sustainable crop management, based on the most important and recently published papers. In addition, the environmental consequences of exaggerate and untreated OMW applications, together with some solutions (strategies) adopted for eliminating soil and groundwater contamination and phytotoxicity are also presented in this review article.

      PubDate: 2017-05-31T06:29:41Z
      DOI: 10.1016/j.agwat.2017.05.008
      Issue No: Vol. 190 (2017)
       
  • Bruising susceptibility of Manzanilla de Sevilla table olive cultivar
           under Regulated Deficit Irrigation
    • Authors: L. Casanova; M. Corell; M.P. Suárez; P. Rallo; M.J. Martín-Palomo; M.R. Jiménez
      Pages: 1 - 4
      Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189
      Author(s): L. Casanova, M. Corell, M.P. Suárez, P. Rallo, M.J. Martín-Palomo, M.R. Jiménez
      The olive tree (Olea europaea L.) is a Mediterranean tree adapted to drought conditions and traditionally rainfed. For irrigated olive groves, there is extensive knowledge about the effects of Regulated Deficit Irrigation (RDI) scheduling on the sensibility of different phenological stages and about the importance of rehydration in the last part of the fruit growth stage. Water stress in this period could reduce the fruit size, but the exact extent of this reduction is still unknown. Additionally, table olive varieties may be damaged during harvesting or processing. This results in bruising, superficial browning injuries that progress through the mesocarp. Bruising susceptibility is an important quality parameter in table olives, however it has been little studied in RDI research. Hand-harvested fruits of ‘Manzanilla de Sevilla’ for green processing, treated with two types of RDI and full irrigation, were bruise-induced with a standardized drop to evaluate bruising susceptibility. Bruising index (BI) and external (BAE) and internal (BAI) bruising damage were measured 3 and 24h after the bruising treatment. A full irrigation treatment was set up in order to maintain the Ψh values higher than −1.2MPa before pit hardening and −1.4MPa until harvest. RDI-1 and RDI-2 were irrigated with a full irrigation treatment until 2 and 4 weeks before harvest, respectively. Then, water was withheld until −2.5MPa. RDI-2 can save 50% of the water applied without affecting the fruit weight, volume or pulp-to-pit ratio (fresh and dry). Fruits under RDI treatments are less susceptible to bruising than fruits with a full irrigation treatment, as evidenced by the lower bruising index and the smaller external and internal damaged area. As for the bruising time line, 3h after the bruise inducement, the bruising index and external damaged area had already developed, whereas internal bruising damage continued increasing up to 24h after the bruising treatment.

      PubDate: 2017-04-30T04:06:24Z
      DOI: 10.1016/j.agwat.2017.04.012
      Issue No: Vol. 189 (2017)
       
  • Using the FAO dual crop coefficient approach to model water use and
           productivity of processing pea (Pisum sativum L.) as influenced by
           irrigation strategies
    • Authors: Paula Paredes; Luis S. Pereira; Gonçalo C. Rodrigues; Nuno Botelho; Maria Odete Torres
      Pages: 5 - 18
      Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189
      Author(s): Paula Paredes, Luis S. Pereira, Gonçalo C. Rodrigues, Nuno Botelho, Maria Odete Torres
      Aiming at improved knowledge on water use, productivity and irrigation scheduling of processing pea, the soil water balance model SIMDualKc was calibrated and validated using field data observed in two farmers’ fields in a wet and a dry year. The model uses the dual crop coefficient approach for partitioning crop evapotranspiration into crop transpiration and soil evaporation. Calibration was performed by minimizing differences between measured and simulated soil water content with a root mean square error representing 2% of the measured mean. The calibrated basal crop coefficients for the initial, mid-season and end-season were respectively 0.15, 1.15 and 1.10. Pea commercial yield (5084–8197kgha−1), obtained from the total yield using industry textural and quality criteria, was influenced by climatic conditions and the harvesting date. Using the global water-yield function with Ky =1.15 and the actual crop transpiration computed with SIMDualKc, the fresh and commercial yields were estimated with errors smaller than 3.5%. Water productivity relative to the commercial yield varied 1.51–2.67kgm−3, mainly depending on the yield achieved rather than on water use. Results from the economic water productivity ratio (EWPR), which compares the commercial yield value with the corresponding production costs, varied 1.07–1.82. Because irrigation costs were a small fraction of the total costs, EWPR values mainly varied with the commercial yield and less with irrigation costs. Irrigation scheduling alternatives for wet and dry years showed that water saving is achievable without considerably affecting peas’ yield and economic results. Results show that the SIMDualKc model is appropriate to support irrigation advising.

      PubDate: 2017-05-05T10:10:30Z
      DOI: 10.1016/j.agwat.2017.04.010
      Issue No: Vol. 189 (2017)
       
  • Automated cycled sprinkler irrigation for spring frost protection of
           cranberries
    • Authors: Faith Olszewski; Peter Jeranyama; Casey D. Kennedy; Carolyn J. DeMoranville
      Pages: 19 - 26
      Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189
      Author(s): Faith Olszewski, Peter Jeranyama, Casey D. Kennedy, Carolyn J. DeMoranville
      Overhead (sprinkler) irrigation is commonly used for spring frost protection of cranberries in southeastern Massachusetts, United States. Historically, conventional forms of irrigation management have been used, generally consisting of running irrigation pumps continuously throughout the night and into the early morning until ambient air temperature reached 1–2°C above the critical temperature of the plant. However, a general paucity of information exists on the horticultural and hydrological effects of on-off “cycling” of irrigation pumps based on pre-programmed temperature setpoints. To fill this gap, three years of monitoring were conducted to quantify the relative effects of cycled and conventional spring frost irrigation on cranberry bud damage, crop yield, and water use. Results showed that cycled irrigation reduced seasonal water use from 33 to 80% compared to conventional frost irrigation, with water savings under cycled frost irrigation ranging from 113 to 198mm (mean±SD: 176±47mm). Despite some variation in type and amount of observed bud damage, values of cranberry yield were similar between the two methods or higher for cycled irrigation. The conventional frost irrigation method always applied more irrigation water, possibly increasing soil saturation and anaerobic conditions that are known to lower crop yield in cranberry. Together, these results point to cycled irrigation as a water management strategy that can enhance cranberry production and reduce agricultural water use in southeastern Massachusetts.

      PubDate: 2017-05-11T09:22:42Z
      DOI: 10.1016/j.agwat.2017.04.014
      Issue No: Vol. 189 (2017)
       
  • Release of phosphorus from crop residue and cover crops over the
           non-growing season in a cool temperate region
    • Authors: T.M. Lozier; M.L. Macrae; R. Brunke; L.L. Van Eerd
      Pages: 39 - 51
      Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189
      Author(s): T.M. Lozier, M.L. Macrae, R. Brunke, L.L. Van Eerd
      In northern climates, crop residue and cover crops are potential sources of dissolved reactive phosphorus (DRP) to runoff; yet, there are few field studies to quantify this. The objectives of this study were (1) to quantify changes in water extractable phosphorus (WEP) concentrations in the residues of Triticum aestivum L. (winter wheat), Trifolium pretense L. (red clover) and Avena sativa L. (oat) cover crops and surface soil in two agricultural fields (ILD and LON) over the non-growing season (NGS); and (2) to determine if changes in WEP in vegetation residue or soil were reflected in loads of DRP or total P (TP) in surface runoff and/or tile drain effluent. Concentrations of WEP in cover crops were larger than those in wheat residue and soil. Water extractable P concentrations in vegetation increased with plant decomposition and decreased following runoff events indicating that the plant WEP was mobilized in runoff. Differences in WEP concentrations were not observed with topography, with the exception of the period following snowmelt when low-lying areas prone to surface inundation were depleted relative to upland locations. Although WEP appeared to have been mobilized from vegetation and soil pools, loads of DRP (0.165–0.245kgha−1) and TP (0.295kgha−1–0.360kgha−1) leaving the fields were small in comparison to P pools in cover crops (7.70kgha−1 oat, 1.70kgha−1 red clover), wheat residues (0.03–0.06kgha−1) and soils (1.39–5.87kgha−1), suggesting that much of the P released from vegetation was retained within the field. This study provides insight into the timing and magnitude of P release from vegetation throughout the non-growing season in regions with cool temperate climates, and provides an improved understanding of the contribution of cover crops to winter P losses.

      PubDate: 2017-05-11T09:22:42Z
      DOI: 10.1016/j.agwat.2017.04.015
      Issue No: Vol. 189 (2017)
       
  • Determining water quality requirements of coal seam gas produced water for
           sustainable irrigation
    • Authors: Dirk Mallants; Jirka Šimůnek; Saeed Torkzaban
      Pages: 52 - 69
      Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189
      Author(s): Dirk Mallants, Jirka Šimůnek, Saeed Torkzaban
      Coal seam gas production in Australia generates large volumes of produced water that is generally high in total dissolved solids and has a high sodium absorption ratio (SAR) which may affect soil structure, hydraulic conductivity, and crop production if used untreated for irrigation. By coupling major ion soil chemistry and unsaturated flow and plant water uptake, this study incorporates effects of salt concentrations on soil hydraulic properties and on root water uptake for soils irrigated with produced water featuring different water qualities. Simulations provided detailed results regarding chemical indicators of soil and plant health, i.e. SAR, EC and sodium concentrations. Results from a base scenario indicated that the use of untreated produced water for irrigation would cause SAR and EC values to significantly exceed the soil quality guide values in Australia and New Zealand (ANZECC). The simulations provided further useful insights in the type of coupled processes that might occur, and what the potential impacts could be on soil hydrology and crop growth. Calculations showed that the use of untreated produced water resulted in a decrease in soil hydraulic conductivity due to clay swelling causing water stagnation, additional plant-water stress and a reduction in plant transpiration. In case the produced water was mixed with surface water in a 1:3 ratio prior to irrigation, the calculated soil SAR values were much lower and generally acceptable for sandy to sandy-loam soil. The use of reverse osmosis treated produced water yielded an acceptable salinity profile not exceeding guide values for SAR and EC; the plant water stress was limited as there was no additional salinity stress associated with the low level of salts. Results further illustrated that accounting for coupled geochemical, hydrological and plant water uptake processes resulted in more accurate water balance calculations compared to an approach where such interactions were not implemented. Coupling unsaturated flow modelling with major ion chemistry solute transport using HYDRUS provides quantitative evidence to determine suitable water quality requirements for sustainable irrigation using coal seam gas produced water.

      PubDate: 2017-05-11T09:22:42Z
      DOI: 10.1016/j.agwat.2017.04.011
      Issue No: Vol. 189 (2017)
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: August 2017
      Source:Agricultural Water Management, Volume 190


      PubDate: 2017-06-20T04:54:12Z
       
  • Inside Front Cover - Editorial Board Page/Cover image legend if applicable
    • Abstract: Publication date: 31 July 2017
      Source:Agricultural Water Management, Volume 189


      PubDate: 2017-06-05T06:55:54Z
       
  • Buy me a river: Use of multi-attribute non-linear utility functions to
           address overcompensation in agricultural water buyback
    • Authors: C.D.
      Abstract: Publication date: August 2017
      Source:Agricultural Water Management, Volume 190
      Author(s): C.D. Pérez-Blanco, C. Gutiérrez-Martín
      The realization of buyback welfare enhancing opportunities is conditioned to the ability of government agencies to place bids consistent with the shadow price of irrigators. However, methods used to inform buyback programmes to date either rely on ex-post trading data that is not readily available in most regions worldwide; or compensate projected foregone income, and thus ignore the effects that buyback may have on other relevant attributes determining utility. This paper uses revealed preference methods to elicit the parameters of a multi-attribute objective function that mimics the observed behavior of irrigators in the overexploited Segura River Basin in SE Spain. Objective functions are used in a series of simulations in which water allocation is progressively constrained to ex-ante reveal the shadow price of water using two alternative compensation measures: i) the foregone income, a proxy of the shadow price typically used in the literature; and ii) the compensating variation that addresses foregone utility. Results show a relevant gap between the two methods For example, restoring the balance in the basin through purchase tenders would demand an investment of million 2400+ EUR (9.6+ EUR m−3) attending to the foregone income method, and million 950+ EUR (3.8+ EUR m−3) (−60.3%) with the foregone utility method.

      PubDate: 2017-05-26T08:47:09Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.196.74.153
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016