Evaluation And Selection Of Different Green Manure Rape Varieties

With the development of modern agriculture,some traditional green manure,such as legume Astragalus,has certain requirements of growing environment in planting,which can no longer meet the needs of agricultural production,so that the development of green manure industry in China has certain limitations.At present,there are few studies on the evaluation of green manure rape at home and abroad.In this paper,19 rape varieties(lines)were used as test materials.Through field experiments,the evaluation of different rape varieties was carried out from the aspects of rape agronomic characteristics,soil and plant nutrient characteristics.Through the field simulated decomposition experiment,the law of rape plant decomposition and its effect on soil nutrients and microorganisms were studied.The purpose of this study is to provide a theoretical reference for the selection and evaluation of green manure specific rapeseed germplasm resources.The main results of this study are as follows:1.Evaluation of agronomic characters of different green manure varieties.The results showed that the growth period of ziyunying was longer than that of rape,except for varieties7,9 and 10,the other varieties entered the flowering stage earlier;the biomass per plant in the flowering stage was positively correlated with the vegetative stage and the flowering stage,and the agronomic characters of each variety in the seedling stage and the flowering stage had significant or extremely significant differences.Therefore,the length of vegetative growth period and growth period as well as the biological yield per plant should be considered in the selection of green manure rape varieties.The performance of No.3 is the best(double low rape 1035).2.Analysis of plant and soil nutrient characteristics of different green manure varieties.Through the analysis of plant and soil nutrients,the results showed that: the difference of nutrient content in seedling stage was significant,the difference of total phosphorus content in flowering stage was significant,but the difference of total nitrogen content was not significant,and the nutrient content in rape was significantly higher than that in ziyunying.Compared with the three control varieties,No.14 and No.16 showed better plant nutrient characteristics,and No.11 showed better soil nutrient characteristics.According to the comprehensive analysis,the results showed that the highest fertilizer effect could be achieved by turning pressure in the full bloom period,and the best varieties were No.14,No.4,No.11 and No.8.3.The decay law of different green manure crops and its effect on soil nutrients.The results showed that the decomposition of green manure plants was affected by many external factors,and the decomposition rule was fast first and then slow.The results showed that the nutrient release rate of half turn pressure was lower than that of full turn pressure,but the difference was not significant;the content of nitrogen and phosphorus in rape residue had a negative relationship with the release rate;before and after decomposition,the content of total nitrogen and available phosphorus and available potassium in soil increased by 25.6%,32.8% and 398.5% respectively,and the nutrient content of soil samples corresponding to each variety was significantly different;the decomposition rate of ziyunying was higher than that of rape.According to the law of plant decomposition and the characteristics of soil nutrients,it is concluded that: in a certain range,increasing the amount of decomposition can accelerate the decomposition of plants and improve the rate of decomposition;13(67)is high in soil nutrients after turning pressure;9 is the best(rape in Xiacun).4.The effect of different rape varieties as green manure on soil microorganism.The results showed that the number of OTU of soil microorganism decreased significantly after the decomposition,but the dominance of soil microorganism did not change significantly.There was a significant difference in the proportion of OTU number of dominant bacteria in soil.The dominant group of Proteus,actinomycetes,acidobacteria and Bacteroides accounted for 83.19% of the total class level.The abundance of Proteus,actinobacteria and Curvularia after decomposition was higher than that before decomposition,while acidobacteria and Bacteroides were the opposite.The results showed that the soil microbial diversity and activity were significantly affected by the decomposition of rape plants.5.Comprehensive screening and evaluation of different rape varieties as green manure.According to the principal component analysis of the comprehensive characters of rape in full bloom period,the late flowering varieties of green leaf mustard and rhubarb mustard have higher nutrient accumulation and biological yield,which are suitable for use as green fertilizer before sowing of late rice;the middle flowering varieties A1 have better performance in each character value,with earlier full bloom period,which can be used as green fertilizer before sowing of middle and late rice.The total scores of biomass and nutrient accumulation of Chinese cabbage and Xiangyou 4 were lower than that of green manure.The performance of other varieties is good.It can be considered to be a grain and fertilizer variety,which can be turned over after the mature period to improve the economic income.