Use a model like CROP-WAT. try with different climate change scenarios, You will see that different results yield from different scenarios for crop yield.
I think Information on intra-seasonal variability may be useful for adjusting the crop planting season. Soil moisture deficits also suggest irrigation may be needed to maintain a certain level of yield. Knowledge of the relationship between climate change and crop yields may be critical for decision making for farmers, business owners’ and governments agriculture related insurance programs, government investment and subsidy programs for drought preparedness, and also for educational programs on climate change.