Factors affecting crop productivity in loess hilly-gully area--taking Wangjiagou watershed as an example
黄土丘陵沟壑区作物生产潜力影响因素分析——以王家沟流域为例

Crop productivity model research is an important means to study agricultural production, but the universally low adaptability of the model limited its popularization and application. Since Geographic Information System (GIS) owns powerful function of analyzing, processing,managing and visualizing spatial data, it has been widely used in agricultural production. The loess hilly-gully area is one of the most serious soil eroded areas in the world and serious soil erosion has made soil quality degrade and land productivity drop. Aiming at characters of serious soil erosion and low and unstable crop productivity, this paper firstly introduces crop production of Wangjiagou watershed in recent ten years. Then, supported by GIS and aided with crop productivity mode YIELD model, combining actual observation data of crops, it analyzes reasons accountable for changes in agricultural production from two aspects of meteorologicfactors (precipitation, temperature) and farming practices, mulching fertilizing and terracing. The result showed that changes of soil moisture and soil nutrient affected by precipitation and soil erosion are the main factors influencing changes in crop productivities.Effective tillage measures can greatly enhance level of soil water and soil nutrient and promote crop productivities.