Grain Potential Productivity of Cultivated Land in Baoji, Shaanxi Province, China

The natural quality index and the utilization quality index in agricultural land classification are essentially two kinds of grain potential productivity, which, we name natural potential productivity and utilization potential productivity of cultivated land respectively. Based on this, we calculated the natural potential productivity and utilization potential productivity of cultivated land in Baoji. Both of them are 980.336x10(4)t and 587.299x10(4)t respectively. The natural potential productivity per unit area is 26.905t/hm(2) and the utilization potential productivity per unit area is 16.118t/hm(2). The natural potential productivity of Chencang District is 172.956 x10(4)t, the maximum, that of Taibai County 10.744x 10(4)t, the minimum. In terms of the utilization potential productivity, that of Fengxiang County is 105.033 x10(4)t, the maximum, and that of Taibai County 6.795x10(4)t, the minimum. But natural potential and utilization productivity per unit area of Fufeng County are 37.954t/hm(2) and 25.011t/hm(2) respectively, the maximum, and those of Linyou County 11.672 t/hm(2) and 7.095t/hm(2) respectively, the minimum.