We used the Agricultural Production Systems sIMulator (APSIM)’s wheat model to simulate wheat yield, biomass, and water productivity under different irrigation allocations at different growth stages in western Kansas.
Long term historic climate data was entered into the model to represent long term climatic fluctuations, and “favorable”, “normal”, and “bad” years in regard to precipitation were established for evaluating yield, biomass, and water productivity responses. Two net irrigation amounts were simulated by the model: 3.9 in and 7.9 in, and were allocated at one or a combination of key growth stages identified as sensitive to water stress (stem elongation, booting, heading, flowering, and early grain filling).
Results indicated that applying 3.9 in irrigation at booting and heading is optimal for obtaining higher yields or biomass with limited water. Lowest yields and biomass were observed when irrigation was applied during or after grain filling stages.
Publication: Araya, A., Kisekka, I., Prasad, P. V. V., Holman, J., Foster, A. J., Lollato, R. 2017. Assessing wheat yield, biomass, and water productivity response to growth stage based irrigation water allocation. (2017). Journal of ASABE. Vol. 60(1).