[Objective]The effects of long-term fertilization on the organic phosphorus(Po)fractions and phoD-harboring microbial community characteristics in black soil were analyzed,as well as the response of Po fractions to key microbial community characteristics was explored,so as to provide a theoretical basis for the efficient utilization of phosphorus in black soil and for the establishment of scientific fertilization strategies.[Method]Based on the long-term fertilization experiment started in 1989 in black soil,five fertilization treatments were selected:no-fertilizer(CK),nitrogen and potassium fertilizers(NK),nitrogen,phosphorus and potassium fertilizers(NPK),nitrogen,phosphorus and potassium fertilizers plus straw return(NPKS),and nitrogen and phosphorus and potassium fertilizers plus manure(NPKM).Soil samples collected from the 0-20 cm in 2018 were used for the study.Chemical sequential fractionation was performed to quantitatively analyze the Po fractions.Illumina Miseq high-throughput sequencing platform and real-time PCR technology were used to qualitatively and quantitatively analyze the characteristics of phoD-harboring microbial community in soil.The relationships among phoD-harboring microbial community composition,Po fractions and soil properties were comprehensively explored through correlation and variance partitioning analysis.[Result](1)Except for NPKM treatment,there was no significant difference in total Po content among different fertilization treatments,while there was a significant difference in the content and proportion in the total Po of Po fractions.Compared with CK,the content of labile Po(LOP)and moderately labile Po(MLOP)were significantly increased under NK and NPKM treatment,and the content of LOP and MLOP under NK increased by 108.7%and 27.5%,respectively,whereas that under NPKM treatment increased by 446.6%and 38.1%,respectively.Compared with the NPK treatment,the content of LOP and MLOP under the NPKS treatment were significantly reduced by 57.7%and 24.0%,respectively.(2)The fertilizer application with organic materials(NPKS and NPKM)changed the community composition of phoD-haboring microorganisms,but had no effect on their diversities.The NPKS treatment significantly increased the abundance of Pseudomonas,and the NPKM treatment significantly increased the abundance of Gemmatimonas.Meanwhile,the NPKS treatment also significantly increased the absolute abundance of phoD genes and alkaline phosphatase(ALP)activity.(3)Correlation analysis showed that there was a significant relationship among phoD-harboring microbial community composition,LOP and MLOP.Variance partitioning analysis showed that phoD-harboring microbial community composition individually explained 12.1%and 10.2%of the variations in the content and proportion of Po fractions,whereas that were 58.5%and 58.7%jointly with ALP activity,and 67.5%and 64.7%jointly with soil organic matter(SOC),respectively.It could be seen that community composition and soil properties(ALP activity,SOC)jointly affected organic phosphorus components,and their impact effect was better than individual indicators.[Conclusion]Long-term fertilization applications altered phoD-harboring microbial community composition,which interacted with ALP activity and SOC explained changes in Po fractions.Chemical fertilizer combined with straw could improve phoD-harboring microbial community characteristics and significantly increased alkaline phosphatase activity,thereby promoting Po mineralization and improving the utilization efficiency of phosphorus in black soil.
关键词
黑土/长期施肥/phoD功能基因/微生物群落/有机磷组分
Key words
black soil/long-term fertilization/phoD-harboring genes/microbial communities/organic phosphorus fractions
维普
万方数据