Yield effects simulation and optimum choices of crop rotation sequences of typical areas on Loess Plateau of China
The field crop rotation experiments usually need to conduct a long period and to do much work.In order to solve this problem,crop models DSSAT3 and ALMANAC were used to study output effect of main crop rotation sequences in typical areas on Loess Plateau.The concepts and calculation expressions of rotation water consumption index,rotation nitrogen consumption index and rotation economic return were advanced and used to evaluate crop rotation benefits on resources utilization efficiency and economic effects.The optimum crop rotation sequence on Guanzhong Plain,Weibei highland and Yinchuan plain is "wheat-maize→wheat-maize" four crops in two year rotation,"wheat→wheat-millet→maize" four crops in three year rotation and "wheat/maize→wheat/maize" four crops in two year relay intercropping rotation respectively.
Through the several occasions to participate in the management of feed industry in our province and for nearly 300 feed production enterprises survey in the past two years,the existing problems and factors to feed safety were analyzed.In order to ensure the safety of animal products,what feed market supervision should be done in Shaanxi province was proposed.