Assessing Wheat Yield, Biomass, and Water Productivity Responses to Growth Stage Based Irrigation Water Allocation

2017 ◽  
Vol 60 (1) ◽  
pp. 107-121 ◽  
Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1918 ◽  
Author(s):  
Margarita Garcia-Vila ◽  
Rodrigo Morillo-Velarde ◽  
Elias Fereres

Process-based crop models such as AquaCrop are useful for a variety of applications but must be accurately calibrated and validated. Sugar beet is an important crop that is grown in regions under water scarcity. The discrepancies and uncertainty in past published calibrations, together with important modifications in the program, deemed it necessary to conduct a study aimed at the calibration of AquaCrop (version 6.1) using the results of a single deficit irrigation experiment. The model was validated with additional data from eight farms differing in location, years, varieties, sowing dates, and irrigation. The overall performance of AquaCrop for simulating canopy cover, biomass, and final yield was accurate (RMSE = 11.39%, 2.10 t ha−1, and 0.85 t ha−1, respectively). Once the model was properly calibrated and validated, a scenario analysis was carried out to assess the crop response in terms of yield and water productivity to different irrigation water allocations in the two main production areas of sugar beet in Spain (spring and autumn sowing). The results highlighted the potential of the model by showing the important impact of irrigation water allocation and sowing time on sugar beet production and its irrigation water productivity.


Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1031 ◽  
Author(s):  
Zehao Yan ◽  
Mo Li

Agricultural water scarcity is a global problem and this reinforces the need for optimal allocation of irrigation water resources. However, decision makers are challenged by the complexity of fluctuating stream condition and irrigation quota as well as the dynamic changes of the field water cycle process, which make optimal allocation more complex. A two-stage chance-constrained programming model with random parameters in the left- and right-hand sides of constraints considering field water cycle process has been developed for agricultural irrigation water allocation. The model is capable of generating reasonable irrigation allocation strategies considering water transformation among crop evapotranspiration, precipitation, irrigation, soil water content, and deep percolation. Moreover, it can deal with randomness in both the right-hand side and the left-hand side of constraints to generate schemes under different flow levels and constraint-violation risk levels, which are informative for decision makers. The Yingke irrigation district in the middle reaches of the Heihe River basin, northwest China, was used to test the developed model. Tradeoffs among different crops in different time periods under different flow levels, and dynamic changes of soil moisture and deep percolation were analyzed. Scenarios with different violating probabilities were conducted to gain insight into the sensitivity of irrigation water allocation strategies on water supply and irrigation quota. The performed analysis indicated that the proposed model can efficiently optimize agricultural irrigation water for an irrigation district with water scarcity in a stochastic environment.


Water ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 251 ◽  
Author(s):  
Haoxin Li ◽  
Dongguo Shao ◽  
Baoli Xu ◽  
Shu Chen ◽  
Wenquan Gu ◽  
...  

2012 ◽  
Vol 26 (5) ◽  
pp. 1183-1200 ◽  
Author(s):  
Lei Jin ◽  
Guohe Huang ◽  
Yurui Fan ◽  
Xianghui Nie ◽  
Guanhui Cheng

2020 ◽  
Vol 63 (6) ◽  
pp. 1813-1825
Author(s):  
Thomas J. Trout ◽  
Terry A. Howell ◽  
Marshall J. English ◽  
Derrel L. Martin

HighlightsDeficit irrigation may maximize net income when irrigation water supplies are limited or expensive.Water production functions are used with economic parameters to maximize net income with deficit irrigation.Net income may be insensitive to the amount of deficit irrigation if production costs are appropriate for anticipated yield.Deficit irrigation increases risk.Abstract. Competition for, regulation of, and depletion of water supplies in the western U.S. has resulted in reduced water available for irrigating crops. When the water supply is expensive or inadequate to meet full crop water requirements, deficit irrigation (DI) may maximize net income (NI) by reducing use of expensive water or irrigating more land with limited irrigation supplies. Managed DI entails rational planning and strategic water allocation to maximize NI when water supplies are constrained. Biophysical and economic relationships were used to develop NI models for DI and determine water allocation strategies that maximize NI under three types of water supply constraints. The analyses determined that potential benefits of DI are greatest when water is expensive, irrigation efficiency is low, the water supply is flexible, and rainfed production is not economically viable. When production costs are appropriate for anticipated yields, NI is less sensitive to DI planning decisions. Deficit irrigation will become more important as irrigation water supplies continue to decline in the future. Net income analysis can assist growers in making rational DI decisions. Keywords: Deficit irrigation, Economic analysis, Irrigation management, Net income, Optimization, Water productivity.


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