江苏省稻麦复种合理轮耕制的研究

A NEW ROTATION TILLAGE SYSTEM FOR RICE-WHEAT MULTIPLE CROPPING IN JIANGSU

Three different tillage methods in 5 different farming regions of diangsu were surveyed by location test examine how these tillage methods effect the soil fertility and the yields of rice and wheat. The results show that sowing at the same term, the yield of wheat with minimumor no-tillage was more prebable to increase, with a greater increment on clay loam than on sandy foam; the yield of hand transplanted rice in no-tillage treatment tended to decrease, with:greater decrement on clay loam than on sandy loam also; and both the change ranges tended to increase grandually from raised south to north (32°10'N-34°30'N).Minimumor no-tillage notably the nutrient contents of the surface soil, but the soil bulk density below 7cm also,increased. Organic matter, available nitrogen, phosphorus and potassium all tended to decrease. Comprehensive analysis of soil fertility indicates that as for fertility enhancement, minimum-or ao-tillage was more advantageous for clay loam than for sandy loam. Based on extensive survey and comprehensive analysis, a new rotation-tillage system was put forward, in which minimum tillage is the principal part, minimum and no-tillage alternate and deep, shallow and no-tillage rotate periodically. This new system continued and developed the merits of different tillage methods, and correctly handled the contradictions between multiple cropping and farming season, farming and promoting the soil fertility, high yield and high efficiency, thus promoting the development of agronomics in Jiangsu. In recent years, this new tillage system has been extended to a total area of 794000ha in Jiangsu. The application of this new rotation-tillage system has increased yield by 7.5×10⁹g and net income by 3.98×10⁹ yuan and gained significant social, economic and ecologic benefits.