A PRELIMINARY STUDY ON THE NATURAL PRODUCTION POTENTIAL OF PADDY SOIL IN DANYANG CITY,JIANGSU PROVINCE
江苏省丹阳市水稻土自然生产潜力的初步研究

In this paper the crop growth simulation model developed by Penning ele Vries in 1988 and Fuzzy mathod are used to analyze the natural production potential of soils under two cropping systems. The results show that the climatic yield potential of the system of simulated wheat/corn-late rice cropping is about 3000kg/ha higher than that of the system of wheat-single rice cropping. The wheat yield can reach or come close to the climatic yield potential under better soil drainage condition , while the climatic yield potential of corn is greatly affected by the yearly rainfall variation. The natural production potential of the paddy soil genuses in Danyang city is 12645kg/ha when the wheat-single rice cropping system is used. But the yield potential can reach 16495. 5kg/ha if the effect of chemical fertilizers on the yield increase is considered. According to the results mentioned above,the wheat production in Danyang city should emphasize the increase of the natural production potential of soils. As for the single rice,its production should mainly depend on the increase of the climatic yield potential of the crop varieties.