Comprehensive evaluation of production characteristics of annual forage crops based on principal component analysis:A case study of Zhuanglang in Gansu

Annual forage crop is an important source of forage supply during spring and winter in the Loess Plateau of Gansu Province. However the optimal choice of annual forage crops has become a bottle-neck in the establishment and development of annual pastures in this area. Accordingly, dry matter, crude protein, acid detergent fiber, neutral detergent fiber, digestible dry matter, digestible dry matter intake, relative feed value, and water use efficiency were used as indicators in a model, which was then subjected to principal component analysis to comprehensively evaluate the production characteristics of annual forage crops in the Loess Plateau in Gansu Province. These results showed that the dry matter yield of Sudan grass was the highest, followed by that of oats, while that of millet was the lowest. This study demonstated that Sudan grass(Sorghum sudanense)could be planted in large scale on the Loess Plateau of Zhuanglang in Gansu Province.