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.

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