Effects Of Different Cultivation Measures On The Quality And Yield Of Direct-seeded Rice In Hilly And Mountainous Area

The seeds are directly sown in the rice field,which reduces the seedling raising process and eliminates the procedures of seedling field preparation,seedling raising,seedling pulling,seedling transportation and manual planting in the traditional cultivation method,which reduces labor,labor intensity,water consumption and production cost.However,at present,there are problems of poor seedling emergence,heavy weeds,and easy collapse in direct seeding rice cultivation in southwest China,resulting in low yield of direct seeding rice cultivation and small area of direct seeding technology promotion.In this study,in response to the problems of direct seeding rice cultivation in southwest China,we carried out the sowing period,sowing volume,fertilizer application volume and fertilizer application method,weed control method and herbicide variety screening of direct seeding rice in Liangping District,Chongqing City,the main rice production area,and Through the study,we expect to further investigate the growth and development pattern and physiological and biochemical characteristics of direct seeding rice,promote the improvement and optimization of direct seeding cultivation technology in hilly mountainous areas,and accelerate the application of light and simplified direct seeding technology in southwest China.The results of the study are as follows.1.Research on the effects of different sowing periods,sowing amounts and fertilization methods on the quality and yield of direct-seeded rice populations.Through the orthogonal experiment of three factors and three levels of sowing period,sowing amount,fertilizer application and fertilizer application method,and the investigation,determination and analysis of many indexes such as seedling quality,tiller status,chlorophyll content,dry matter accumulation,nitrogen content,root injury flow strength,POD enzyme activity,agronomic traits,economic traits,yield and rice quality of direct-seeded rice,the results showed that the three factors on the yield of direct-seeded rice The effects of three factors on the yield of direct-seeded rice were: sowing period > fertilizer application amount and fertilizer application method > seeding amount,among which sowing period,fertilizer application amount and fertilizer application method had significant effects on the yield of direct-seeded rice.In the 400-500 m altitude rice area of Chongqing,the seeds were sown from April 11 to 18,1-1.5 kg of seeds per mu,15% N reduction and optimized fertilization(18.7kg of urea per mu,30% of base fertilizer,30% of 4 leaf chasing fertilizer,20% of flower promotion fertilizer and 20% of flower preservation fertilizer).The quality is better and the yield is higher.2.Research on weed prevention and control technology for direct-seeded rice cultivation.Four different application methods were adopted and eight chemical herbicides were selected to investigate the effects of different herbicides and application methods on weed control,seedling growth and yield of direct-seeded rice.The results showed that the combination of 2.5 %penoxsulam + 20% cyhalofop-butyl was more effective in preventing barnyardgrass,duckweed and hollow lotusgrass.The seedlings grow vigorously and the yield of live rice is high.3.Research on flooded rice direct seeding cultivation technology.The results show that long-term flooding will reduce the seed emergence rate and seedling quality,especially for varieties with poor low oxygen tolerance,and the emergence rate of the 12 varieties investigated at 15 days of flooding is between 16 and 60%.Therefore,the flooding time should be controlled within 15 days and the flooding depth should be 5-7cm,and the varieties with strong low oxygen tolerance should be selected in order to achieve the effect of preventing bird feeding on seeds and suppressing weeds without seriously reducing the seedling emergence rate and seedling quality.The test screened four varieties with strong low oxygen tolerance,namely Dasangyou 1 1 1,Chuangyou 538,Shen9 you 28 and Uyou 1508.4.Identification of the fruitfulness,adaptability and resistance of rice direct seeding cultivation.Eight rice varieties promoted in the southwest were selected for live cultivation to identify their yield,adaptability,disease and insect resistance and quality,etc.The results showed that: either three-series hybrid rice or two-series hybrid rice can be cultivated live,but there are differences in yield,resistance and quality of different varieties cultivated live,and the varieties with good overall performance are Shen9 You28,U You1508,C Two-You Yuehe Silk Miao and The four varieties of U8 U528 can be cultivated live in the one-season medium rice area at an altitude of 800 meters in the southwest.