Assessment of climate change impact on maize (Zea mays L.) through aquacrop model in semi-arid alfisol of southern Telangana

The study was under taken at ICAR-CRIDA, Hyderabad (India) to assess the climate change impact on maize crop. There were five main irrigation treatments viz., I0, I1, I2, I3, I4, two sub treatments viz., M0 (no mulching), M1 (mulching @ 5 t ha-1 with glyricidia) and two sub-sub treatments viz., NF (normal fertilizer) and HF (high fertilizer) to study the effect of supplemental irrigation and crop management practices on maize grain yield and water productivity in semi-arid alfisols of Telangana state. The results of the study indicated that, the highest average grain yield of 3.19 t ha-1 was recorded in I4 and lowest was in I0 (1.78 t ha-1). The highest average water productivity (10.65 kg ha-1 mm-1) was recorded in I4 followed and the lowest was in I0 (7.60 kg ha-1 mm-1). The AquaCrop model was calibrated for simulation of grain yield and water productivity for all treatment levels and the prediction error statistics were 0.94 < E < 0.95 %, 0.06 < 0.12 t ha-1 and 0.59 < 0.82 t ha-1. During the validation, model performed well with model efficiency of 91 % and 73 % for grain yield and water productivity respectively and is within the acceptable limits. Under the changing rainfall and air tem-perature, the maize grain yield under rainfed condition can be sustained by application of supplemental irri-gation of 50 mm with expected increase in maize yield by 28.39-74.79 per cent in RCP 4.5 and 34.81-85.27 per cent in RCP 8.5 from near century (2025) to end century (2090) as compare to kharif 2013 in Rangareddy district of Telangana state.

Automated summary

The study assessed the impact of climate change on maize crop and found that supplemental irrigation and crop management practices improved grain yield and water productivity. The AquaCrop model accurately simulated the results.