The researchers calculated crop coefficients using the Penman-Monteith method in Guanzhong Shaanxi to improve water management for crops. They found that there were significant differences in crop coefficients for winter wheat between the Penman and Penman-Monteith methods, but not for summer maize. Winter wheat crop coefficients should be updated using the Penman-Monteith method, while summer maize does not need to be adjusted.