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Response Of Temperature And Light Resources Utilization Characteristics And Soil Microbial Community Structure To Slow-release Nitrogen Fertilizer Application In Double Cropping Rice With Mechanical Transplanting Under Rice-Rice-Rapeseed/Rice-Rice-potato

Posted on:2021-05-14Degree:MasterType:Thesis
Country:ChinaCandidate:Y F DuFull Text:PDF
GTID:2480306518989799Subject:Seed science and technology
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In this paper,two early rice varieties and two late rice varieties promoted in Hunan Province were selected as experimental materials under the conditions of Rice-Rice-Rapeseed/Rice-Rice-Potato multiple cropping system.Six different slow-release nitrogen fertilizer combinations were designed and applied.The effects of different slow-release nitrogen fertilizers on the microbial diversity of paddy soil in six important periods and the utilization characteristics of temperature and light resources of tested varieties were analyzed.The purpose of this study is to explore the annual production characteristics of Rice-Rice-Rapeseed/Rice-Rice-Potato multiple cropping system and the response mechanism of soil environment,so as to establish a green,production-increasing and efficiency-improving management planting model on the premise of saving resources and reducing pollution.The results are as follows:1.Compared with conventional urea treatment(F2),the effect of 1:1 resin coated urea fertilizer combined application(F3)on the yield of double cropping conventional rice was not significant.In the Rice-Rice-Rapeseed model,the annual yield of double cropping conventional rice under 30% nitrogen reduction treatment(F4)was 10.9% lower than that of the counterpart under 1:1 resin coated urea treatment(F3).The annual yield promoted by commercial organic fertilizer(F5)and biological carbon treatment(F6)were 11.57% and16.53%,respectively,higher than that promoted by 30% nitrogen reduction treatment(F4).In the case of double cropping hybrid rice,the annual yield under 30% nitrogen reduction treatment(F4)was 13.24% lower than that under the treatment of 1:1 resin coated urea(F3).Applying commercial organic fertilizer(F5)and biological carbon(F6)increased the yield by17.39% and 14.8% respectively.Under the mode of Rice-Rice-Potato,for the double cropping conventional rice,the annual yield decreased by 3.36% under the treatment of 30%nitrogen reduction(F4)than the treatment of 1:1 resin coated urea(F3),and the annual yield in the case of using commercial organic fertilizer(F5)and biological carbon(F6)were 3.69%and 3.28%,respectively,higher than the case of using the treatment of 30% nitrogen reduction(F4).For the double cropping hybrid rice,the annual yield decreased by 4.82%under the treatment of 30% nitrogen reduction(F4),compared with that under the treatment of 1:1 resin coated urea(F3).The annual yield promoted by commercial organic fertilizer(F5)and biological carbon(F6)increased by 4.34% and 3.99% respectively,compared with using the treatment of 30% nitrogen reduction(F4).2.After combining with different slow-release nitrogen fertilizer treatments,the diversity of alpha in the soil microbial community of paddy field was enhanced,and the community structure of beta diversity of soil samples in each period shows a significant difference,which was in the abundance when the dominant flora and common flora types did not change significantly.This indicated that slow-release nitrogen fertilizer treatment could improve the microbial diversity and species richness of the soil in paddy field.3.The composition of soil microbial community and the abundance of dominant and common microbial communities were significantly affected by rotation mode and the combined application of slow-release nitrogen fertilizers.Different rotation treatments significantly changed the phylum abundance of Actinobacteria and Firmicutes.Different slow-release nitrogen fertilizer treatments significantly affected the phylum relative abundance of dominant flora such as Proteobacteria,Chloroflexi,Acidobacteria and Actinobacteria,and also affected the relative abundance of common flora such as Firmicutes,Nitrospirae and Gemmatimonadetes.Compared with conventional urea fertilization,slow-release nitrogen fertilizer treatment optimized the microbial community structure and increased the microbial diversity of paddy soil.4.The results of correlation analyses showed that soil temperature,soil humidity,air temperature,and light intensity had a high correlation with the dominant microbial communities in most paddy soils,while soil p H,UV radiation and photosynthetically active radiation had a high correlation with the dominant microbial communities in some paddy soils.The effects of environmental factors on microbial community structure are different.
Keywords/Search Tags:Slow-release nitrogen fertilizer, Mechanical transplanting double cropping of rice, Soil microorganism, 16S rRNA
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