Impact of irrigation and other inputs on farm productivity in the upper and middle parts of the Yellow River basin, China

Abstract

This paper reports a study on the impact of resource use, irrigation in particular, on farm productivity in the upper and middle parts of the Yellow River basin, China. A comprehensive database was constructed with processed geographical, climatic, hydrologic, and economic data to provide information for the current and future studies. Descriptive statistics and correlation analysis were used to characterize the temporal trend and spatial variation in farm productivity and resource use. Regression models were developed to evaluate the farm productivity over different land-use types and to quantify the impact of inputs on farm productivity. Data analysis results indicated that the average farm productivity in the region increased by 1.67 fold during the period of 1980–1999, which was largely attributed to the intensive application of resources and technology inputs. The spatial pattern of precipitation was displaced with that of cultivation, causing the farm productivity in the region to be associated more with irrigation than with precipitation. The average farm productivity of irrigated cropland was 13 times that of rainfed cropland, that is, about 13 ha of rainfed cropland was needed to produce the same amount of farm products as that from one ha of irrigated cropland with the same species and quality. Irrigation could approximately double the farm productivity of rainfed cropland with other affecting factors remaining the same at the mean level over the region and stood as the most dominant factor in controlling farm productivity in the region. Farm productivity was also highly correlated to the application of chemical fertilizer in the period of study. Results from this study provided a strong economic argument for converting the less cultivable cropland back to natural ecosystems and an urgent call for directing future development in the region in a sustainable manner.