SUSTAINABILITY OF WATER RESOURCE AND ECONOMIC CROP PRODUCTIVITY, INNER MONGOLIA, NORTHERN CHINA

The planting structure of crops and the sustainability of the water resources should be reasonably planned to alleviate the overexploitation of groundwater in Inner Mongolia. Therefore, the variations of precipitation, surface water and groundwater from 2000 to 2017, planting area and yield of maize from 1947 to 2917 was analyzed in our study. Main results showed that precipitation steadily increased with years, and significantly affected the surface water and groundwater (R2≥0.85). Presently, the total water resource was 30.993 billion m3, the agriculture irrigation water was 12.085 billion m3, and the water consumption of groundwater was 8.533 billion m3. In recent years, the amount of water used for agriculture irrigation decreased markedly, mainly relying on groundwater. With the gradual increase of the area of water saving irrigation, the irrigation area using sprinkler irrigation and drip irrigation technology increased significantly, reaching up to 1.4445 million hm2 in 2017, compared with the other irrigation patterns. Although the planting area of food crops in the proportion of the planting area of total crops seriously decreased, but maize, as the primary food crops and economic crops in the local region, its planting area in the proportion of planting area of all food crops continuously increased, and yield of maize also continued to increase. By 2017, the planting area of maize was up to 3,716,300 hm2, yield of maize was 6,720kg hm-2, which was positively correlated with water storage in reservoirs. Therefore, it was necessity to adopt the planting pattern of high efficiency and water saving for improving the water use efficiency, reducing the use of groundwater, and achieving water saving agriculture and sustainable development of water resources.