不同水旱轮作模式对稻田土壤肥力和微生物群落结构的影响OA

[Objective]The effects of different paddy-upland rotation patterns on paddy soil fertility and microbial community structure were investigated to provide a basis for screening of high-efficiency rice planting models,optimization of paddy field nutrient management,and scientific fertilization decision in Guizhou Province.[Method]The soil physicochemical indicators under three rotation patterns of winter potato-rice(PR),winter wheat-rice(WR)and winter rapeseed-rice(WR)were determined by a randomized block design,and the changes in soil microbial community structure and relationships between soil microbial community structure and soil nutrients under different crop rotation patterns were analyzed by Illumina high-throughput sequencing technology.[Result]There were significant differences in soil physicochemical indicators after harvesting different preceding crops.The TN,TP,TK,NN and AN content of the soil after harvesting winter potato was significantly higher than that after harvesting winter wheat and winter rapeseed.Planting rice could increase soil pH,and effectively alleviate the soil acidification trend caused by winter cropping season.After harvesting rice,the TK and NN content of the soil under the potato-rice rotation pattern was the highest among three crop rotation patterns,and there was no significant difference in soil TP content among three crop rotation patterns.There was a great difference in relative abundance of soil bacteria and fungi at phylum level among three crop rotation pattern.The preceding crops had the significant effect on composition of bacteria and fungi communities.The dominant soil bacterial phyla of three crop rotation patterns were Proteobacteria,Acidobacteriota and Chloroflexi.The dominant soil fungi phyla of three crop rotation patterns were Ascomycota,Basidiomycota and Mortierellomycota.After harvesting winter potato,the Proteobacteria(38.29%)and Ascomycota(95.41%)dominated the advantage in soil microbial communities,which indicated that the unicity of microbial communities was relatively high.After planting rice,the relative abundance of Acidobacteriota and Chloroflexi increased,and the community structure became more complex.There was obvious difference in soil microbial community structure among three crop rotation patterns.The pH,NN and AN of the soil were the key factors influencing soil microbial community structure.The correlations between soil bacterial communities and soil physicochemical indicators were more higher.[Conclusion]The paddy-upland rotation pattern can effectively improve the cropping index and land utilization efficiency of paddy fields.During the rice cultivation season,the soil ecosystem stability of paddy fields can be maintained by regulating soil acid-base balance and optimizing microbial community structure,which is beneficial to safeguarding regional cultivated land quality and food production.