We investigated optimal applications of pre-plant irrigation dependent on irrigation capacity through the CERES-Maize model embedded in RZWQM2 model with long-term climate scenarios. By comparing yield, water productivity, precipitation use efficiency, and soil water evaporation losses prior to planting, we make recommendations on pre-plant irrigation applications for corn in southwest Kansas.
Various scenarios were run to simulate the impact of pre-plant irrigation treatments under various irrigation capacities. We found that while under low irrigation capacities, pre-plant applications raised yields, this was only when yield targets were 95-159 bu/ac. Ensuring high irrigation capacity during the growing season had a much more significant impact on yield.
The amount of pre-plant irrigation applied had little impact on water productivity under moderate and high irrigation capacities. However under limited irrigation capacity, pre-plant applications did increase water productivity. Increasing pre-plant irrigation applications increased soil water evaporative losses.
Overall, if an operation is capable of moderate and high irrigation capacities, an operator has little to gain from applying pre-plant irrigation. It is only under specific seasonal conditions that modest yields gains can be realized from pre-plant irrigation under limited irrigation capacities.
Publication: Kisekka, I., A. Schlegel, L. Ma, P.H. Gowda, and P.V.V. Prasad. (2017). Optimizing preplant irrigation for maize under limited water in the High Plains. Agricultural Water Management 187 (2017) 154-163.