A computational framework for irrigation scheduling of a winter wheat – summer maize rotation system

One of the solutions for the current problem of limited arable land and growing demand for food is the increase of the land use intensity, e.g., by crop rotation. However, it can lead to excessively high agricultural water demand. We evaluate a winter wheat-summer maize crop rotation system, the main cropping system in the North China Plain, and develop a computational framework for optimal irrigation of two consecutive crop growth periods within a single year. The framework considers the impact of climate variability and considers limited agricultural water allocation.  In a case study for a site in the North China Plain, the framework is implemented using Aquacrop-OS that simulates the soil water balance and the interactions between two consecutive cropping seasons. A two-stage optimization ensures the maximum global crop water productivity, considering the food risk and yield stability. The developed framework can be used for optimal irrigation scheduling and as a tool for estimating minimum irrigation water demands and crop productivity for more sustainable water resources management on a regional level.