Study On Technological For No-tillage With Straw Mulching Precise Sowing Of Directly-seeded Summer Soybean After Winter Wheat

To understand and resolve the disadvantages existed in summer soybean production of Huang-Huai-Hairegion, such as the stubble handling, intense time and poor quality of sowing after wheat harvest, thisthesis mainly studies the precise sowing technology with well seedling protection of summer soybean.By comparing the differences of three sowing methods (no-tillage with straw mulching precise sowing,conventional mechanical sowing and artificial small columbine sowing) in seedling condition, growthvigor, yield, cost and benefits, the cost-benefit analysis was conducted, the practicability and utilityvalue of the technology were explored, in order to optimize the technology system of summer soybean,and to provide technical support to summer soybean production in the Huang-Huai-Hai region. Theresults were summarized as follows:1. The no-tillage with straw mulching precise sowing obviously reduced the hardness of seed bed. Soilhardness (2.9kg/cm~2) and inter-row soil hardness (13.7kg/cm~2) were both lower than that of the othertwo, which indicated that this method was conducive to emergence and growth of soybean as it canloosen soil of sowing lines and inter-rows.2. The no-tillage with straw mulching precise sowing was propitious to soil moisture conservation dueto the straw cover, which gave small diurnal variation to soil moisture. The other two methodsperformed a great variation of soil moisture.3. The no-tillage with straw mulching precise sowing can significantly increase soybean sowingevenness with a higher qualified index than the other two methods. Conventional mechanical sowingshowed the middle qualified index and reseeding index, as well as the highest missing sowing index,while the artificial sowing showed the lowest qualified index, middle missing sowing index and highestreseeding index.4. The no-tillage with straw mulching precise sowing is beneficial to soybean growth and development.It was proved that the agronomic traits and yield structure were better than that of soybeans with theother two methods.5. The no-tillage with straw mulching precise sowing reduced the costs. The costs were30.0yuan and78.0yuan less per MU separately than conventional mechanical sowing and artificial small columbinesowing, while under thinning conditions, the number were50.0yuan and138.0yuan per MU.6. The no-tillage with straw mulching precise sowing can increase benefits. The economic benefits was55.2yuan and125.6yuan more per MU separately than conventional mechanical sowing and artificialsmall columbine sowing, while under thinning conditions, the net income increased by84.5yuan and216.5yuan per MU.7. The technological system for precise sowing and seedling preservation of directly-seeded summersoybean after winter wheat in Huang-Huai-Hai region was initially proposed in this study. Soybeanvarieties, seedtime, sowing density and fertilizer amount were also established in the testing areas.