Simulating the climate change impacts and evaluating potential adaptation strategies for irrigated corn production in Northern High Plains of Texas

Sustaining irrigated corn (Zea mays L.) production under changing climate and reduced irrigation water availability presents a key challenge for producers in the Northern High Plains (NHP) of Texas. We assessed climate change impacts on corn production at Bushland in the NHP region using the CERES-Maize model under 36 future climate scenarios. These scenarios included nine global climate models (GCMs), two representative concentration pathways (RCPs) 4.5 and 8.5, and two future time periods 2050s (2036–2065) and 2080s (2066–2095). Simulated grain corn yield decreased, under all scenarios in the future, by approximately 31 % on average in the 2050s and by approximately 55 % in the 2080s, under RCP 8.5, mainly due to reduced unit grain weight and biomass, and shorter crop cycle. Seasonal irrigation water use was simulated to either increase or decrease in the future depending on the rainfall projection of a GCM. Adaptation strategies considered in this study included using ideotypes with a longer maturity, higher yield potential, and greater heat tolerance than the reference cultivar, and shifting of planting dates. The ideotypes were created by modifying thermal times from emergence to end-of-juvenile phase, thermal time from silking to maturity, maximum kernel number per plant, radiation use efficiency (RUE), and optimum and failure temperature thresholds during relative grain filling. The planting dates considered were 16 April, 1 May, 16 May (reference), 1 June, and 16 June. By increasing the reproductive period by 13 days, grain yield could increase by 40 %, but that could increase seasonal irrigation water requirement by 10 %. Grain corn yield increased by 13 % on average when the maximum number of kernels per plant or RUE were increased by 15 %, with minor changes in seasonal irrigation water requirement. Heat tolerant ideotypes showed yield advantage over the reference cultivar without much change in irrigation. Delayed planting increased grain yield in the future. Overall, grain yield could decline under climate change without adaptation. Ideotypes with greater silking to maturity period, potential number of kernels per plant, RUE, and heat tolerance during grain filling, showed yield benefits in the future.