The Impact of Water Deficit on Yield Response Factors: A Case Study of Cotton and Silage-Maize in İslahiye

Understanding the effects of water deficit on crop yield is essential for growers and researchers, as it represents a crucial uncertainty in agriculture, along with factors such as sales price, tenure, input costs, and input quality. This study compares and analyzes the yield response factors of two crops, cotton and silage maize, to water deficit using data from Islahiye town of Gaziantep Province in Türkiye. The primary data source is the 2016 Türkiye Plant Water Consumption Guide, prepared by TAGEM and DSI using the FAO Penman-Monteith method. The yield response factor Ky indicates the sensitivity of the crop yield to the potential evapotranspiration (PET) deficit in ten-day periods, t. Their yield response factors change depending on the growth stage and percentage of water deficit. Our model is based on water production function and the soil moisture balance equation, and the model can be applied to all crops, including herbaceous, trees, and vines. The water shortage rate is the same for each t. The solution of the maximization model by a Mixed-Integer Programming (MIP) Solver revealed that both crop yields are considerably affected by water deficits, with similar sensitivities observed. However, while cotton is more sensitive until a 15 per cent deficit, silage maize becomes more sensitive beyond this value. The findings will have a significant impact on decision-making for water allocation, ensuring optimal use of this essential resource. This model and its solution use optimization algorithms to provide new knowledge and perspectives to manage water deficits better and optimize crop yields.