Assessing crop yield and water balance in crop rotation irrigation systems: Exploring sensitivity to soil hydraulic characteristics and initial moisture conditions in the North China Plain

Abstract

Multiple cropping is an effective measure to enhance the intensity of land use. The North China Plain is one of China’s most important grain production areas, with 70 % of the arable land under double rotation of winter wheat and summer maize. The allocation of irrigation water between two crop seasons depends on soil water flow and crop water consumption. This is because the amount of moisture left in the soil at the end of one season affects how much moisture is in the soil at the beginning of the next season. As a result, the amount of crops produced and the amount of water needed for irrigation are influenced by the initial soil moisture conditions and the soil’s hydraulic properties. This study aims to analyze how various factors affect crop yield when faced with water scarcity. The factors considered include initial soil moisture condition, soil texture, and irrigation scheduling. The simulation results indicate that, in most cases, initial soil moisture conditions have a more significant impact on crop yield than soil hydraulic characteristics. The impact of irrigation can differ based on the irrigation method and availability of water. Hence, when distributing irrigation water over a year, it is crucial to consider the soil’s water transport between two crop cycles to achieve the ideal full and deficit irrigation in a crop rotation system. Additionally, a joint optimal irrigation plan can significantly reduce the adverse effects of unfavorable soil hydraulic characteristics. Moreover, the optimal irrigation strategy can enhance crop water productivity and food security simultaneously.