Effect Of Straw Mulching And Soil Tillage On Yield Formation And Water Use Efficiency Of Late Rice In Southern Hunan

Rice is the most important food crop for China, while it needs a large amount of water. Therefore, the development of water saving technology in the production of rice is of great significance to the shortage of water resources in China. The technology of water-saving and drought resistance in south China lags behind the technology in northern China. However, under the background of global warming, the drought situation is becoming increasingly serious in South China. In this study, the study included the late rice In the Hilly Region of southern Hunan, and I study on straw mulching and tillage measures effect on rice yield, rice quality, water use efficiency and nutrient absorption and utilization rice yield, and physiological mechanism of the rice. This provides a basis for the construction of water-saving technologies in rice cultivation system in southern Hunan. The main results are as follows:(1) Compared with the deep irrigation, the yield of shallow irrigation treatment was higher about 5%, and the reason mainly lied in shallow irrigation could inhibit the occurrence of ineffective tillers, delay leaf senescence, improve photosynthetic rate and dry matter accumulation at late stage, whch resulted in improvement of effective panicle number and seed setting rate.(2) In this study, yield in treatment of mulching with rice straw was lower than that of control, yield in plowing treatment was significantly higher than that of no-tillage treatment by 10%. Under the same soil tillage mode, yield of treatment of ridge cultivation was lower than that in common cultivation treatment, specially it decreased significantly under no-tillage condition.(3) The appearance quality of rice in shallow irrigation conditions was higher than that under the conditions of deep irrigation, the cooking and eating quality, processing quality of the late rice in either case had little difference. The cooking and eating quality, processing quality of the late rice in the tillage conditions were better than those under the conditions of flat planting.(4) Soil plowing promote absorption of nitrogen, phosphorus and potassium of rice, and content and accumulation of nitrogen, phosphorus and potassium was increased significantly, and the fertilizer efficiency of nitrogen, phosphorus and potassium were increased by 12.9%, 11.2% and 12.5%, respectively.(5) In the shallow irrigation conditions, rice yield increased significantly, and amount of irrigation was decreased, while water use efficiency of rice was improved significantly, in which irrigated water use efficiency and total water use efficiency were increased by 100% and 35% respectively. Straw mulching improved water use efficiency by reducing the field evapotranspiration to maintain soil moisture. Under condition of ridge cultivation, water use efficiency of rice was increased significantly, irrigated water use efficiency was improved by more than 50%, and water use efficiency was improved by 10%.