Study On The Adjustment Of Planting Structure In Collecting Rainfall And Water-saving Irrigation Area Of North Of Loess Plateau

Based on the climatic data from 1959 to 2001 and statistical data from 1980 to 2003 in Jungar Qi and the field experiments in different crops types and crop varieties during 2003 and 2004, the climatic condition, the water comsumption, crop yield, quality of the crops were analyzed. Combined with the feed comsumption of livestocks, the linear programming model of cropping structure adjustment has been established.(l)Compared with that in 1960s, the annual average temperature from 1996 to 2001 increased by 1.0°C. The precipitation was not change as significantly as before. The yearly sunshine hours has decreased by 150.0 hours. To some extent, these changes have impacted on agricultural production.(2)According to the requirement of different crops, the crop potential productivity has change a lot as the climatic changes. The result showed that the variation trend of photosynthetic productive potentiality, photosynthetic and temperature potential productivity and climatic productive potentiality in different years are decreasing.(3) Founded on the observation of field experiment in 2003 and 2004, the differences between representative crop types and varieties were observed and analyzed.Millet have good characteristic of drought-resistance among the crops, and millet varieties of Xiaoxianggu and Yumi- Ⅱ are berrer than the others. Maize requires more water than the other crops, and Zhedan-Ⅶ is better variety. Zhongmu-Ⅰ and Chuangxin are better clover varieties.(4)Based on the integrated economy, society and ecology benefits, the proper cropping structure in Jungar Qi should be 60.7% of grain crops, 17.8% oil crops and 21.5 % forage crops. The total annual net income of planting would be 218.8 million yuan increased by 4.28 million yuan compared with the present planting structure.