Cultivated Land Productivity Evaluation And Improvement Strategies In Northwest China

This research analyzes the dynamic evolution of cultivated land productivity in Northwest China from two aspects of time(1982-2012) and space(five provinces in northwest area). By studying the arable land grade of northwest area based on national land natural quality, economy and utilization, analyzing the arable land grade influencing factors and its weight of land quality and its spatial differences, studying both in theory and practice quantitatively and qualitatively, an strategy of cultivated land quality promotion and management was presented. The results are shown as the followings:(1)In order to evaluate the relative importance of cultivated land productivity of Northwest China in the whole country, its productivity and the dynamic evolution of cultivated land pressure there were analyzed. It is found that in recent 30 years’ time in Northwest China the cultivated land productivity shows a trend of small scale fluctuations but continuous rising, but its land capacity was still lower than the national average level. The pressure level was always at the II rank, and it is a critical state.(2) In order to evaluate the arable land grade structure in Northwest China and its position in the whole country, the characteristics of land grade in quantity and spatial distribution differences were analyzed. The result shows that, there are more medium and low grade lands in northwest area, and the average land grade there is lower than the national average. The distribution of arable land natural quality and utilization grade was roughly the same in Northwest China: high-grade lands mainly in Shaanxi. And the distribution of arable land economic grade was slightly different: high-grade arable land mainly in Xinjiang.(3) This research shows the primary factors which would influence the cultivated land quality and spatial distribution, including geomorphologic structure, soil conditions and agricultural constructions. The distribution of the factors in each northwest province depends on each province’s own dominant factor.(4)At last, a strategy of northwest area’s cultivated land quality promotion and management in the future was presented.These should be paid attention to, including to improve the soil condition of medium-low productive land, to restore ecosystem of degraded land, to invest in agricultural water conservancy construction and water saving technology promotion. Cultivated land protection system should be built with the economic incentive as the core and an interest driven mechanism of cultivated land protection should be designed comprehensively.