Water resource management for irrigated agriculture in China: Problems and prospects

Agriculture underpins the continuous development and progress of society. As water resources impose a major constraint on economic and social development, strengthened management and scientific allocation of water resources for agricultural purpose has become a hot issue of concern for countries around the world. This is particularly important for China, a large, populous country, to safeguard its food security. In 2010, irrigation, on which China's crop production is highly dependent, contributed 32.4% of the national grain yield. With rapid economic development, however, agriculture has always faced competition for water with nonagricultural sectors. Given water and land shortage and growing rigid grain demand in China and based on the decoupling theory, this paper analyses the relationship between grain yield and irrigation water use from 2000 to 2020. The paper examines the impacts on grain yield brought by such factors as irrigation water use, effective irrigation area, fertilizer application and labour input and explores China's agricultural water security mechanism. The results show that grain yield has been significantly affected by irrigation water use, but such dependence is gradually reducing at this stage. China tries to guarantee agricultural water use by developing farmland water conservation and water-saving irrigation, but future agricultural water use will be affected by a variety of factors, including the intensified constraint of adversely distributed water and land resources, poor operation and management of irrigation works, transfer of water rights from agriculture to industry and potential conversion of irrigated areas. This calls for red lines that define the lower and upper limits of agricultural water use to ensure agricultural water security.