采用田间定位试验（始于2011年）研究施用磷肥对稻油轮作土壤磷组分及微生物多样性的影响。试验设置NK（-P）和NPK（+P）2个处理，按0~10、10~20、20~30和30~40 cm土层进行采样和分析。各土层有效磷、全磷和有机磷含量按常规方法测定；土壤无机磷组分采用化学连续提取法测定，并利用IlluminaMiSeqPE 250平台进行表层土壤（0~10 cm）微生物高通量测序。结果显示：与对照（-P处理）相比，长期施用磷肥（+P处理）能显著增加各土层总磷、无机磷和有效磷含量，而有机磷含量处理间差异不明显。从土层有效磷含量来看，施用磷肥可显著增加0~10 cm和10~20 cm两个土层磷含量；对于20~30 cm和30~40 cm土层的影响效果不显著。与对照相比，长期施用磷肥会降低细菌和真菌菌群的Alpha多样性，菌群群落结构发生明显改变。在细菌门水平上，绿弯菌门、酸杆菌门和变形菌门为优势菌门，磷肥施用后表层土壤绿弯菌门和酸杆菌门相对丰度增加，而变形菌门相对丰度降低。在真菌门水平上，担子菌门和子囊菌门为优势菌门，磷肥施用后表层土壤子囊菌门相对丰度降低，而担子菌门相对丰度增加。与对照相比，磷肥施用虽然引起耕层土壤中细菌和真菌数量在各分类单元显著降低，但从属分类水平来看，优势菌群的相对丰度也随之降低。冗余分析结果表明铝磷、铁磷含量与表层土壤优势细菌和真菌的丰度密切相关。可见，长期磷素亏缺会诱导微生物数量增加以活化土壤养分，而充足的磷肥供应则能够满足作物养分需求，维持土壤微生物群落动态平衡。因此，有必要就整个轮作系统磷肥施用进行优化，促进土壤磷素活化和释放，从而减少磷肥用量，提高其吸收利用率。
A field experiment with two treatments including NK (-P) and NPK (+P) was conducted in 2011 to study the effects of long-term application of phosphorus (P) fertilizer on the phosphorus fractions and microbial diversity of rice-rapeseed rotation. The soil layer was divided into 0-10、10-20、20-3+E1070 and 30-40 cm for sampling and analyzing. Soil available P,total P and organic P were determined with conventional analytical methods. Chemical continuous extraction method was used to determine the inorganic P fractions in the soil samples,and Illuminamiseqpe 250 platform was used for high-throughput sequencing of surface soil (0-10 cm) microorganisms. The results showed that long-term application of P fertilizer (+P) significantly increased the content of total P,inorganic P and available P in each soil layer compared with the CK (-P treatment),but the organic P content did not increase significantly. P content in soil layer of 0-10 cm and 10-20 cm significantly increased by application of P fertilizer,but the effect on the bottom layer of 20-30 cm and 30-40 cm was not obvious. Compared with -P treatment,long-term application of P fertilizer reduced the alpha of microbial community diversity and changed the structure of microbial community. At the level of phylum,the dominant bacteria were Chloroflexi,Acidobacteria and Proteobacteria. The relative abundance of Chloroflexi and Acidobacteria was increased,while that of Proteobacteria decreased. Ascomycota and Basidiomycota were the dominant phylum,the relative abundance of Ascomycota decreased and that of Basidiomycota increased. Compared with CK,although the application of P fertilizer significantly decreased the number of bacteria and fungi in the layer soil in each taxa,the relative abundance of the dominant flora decreased from the perspective of the genus level. The results of analyzing redundancy showed that the content of Al-P and Fe-P was closely related to the abundance of various bacteria and fungi. It is indicated that long-term phosphorus deficiency induce an increase in the number of microorganisms to activate soil nutrients,and a sufficient supply of phosphorus fertilizer meet crop nutrient requirements and maintain the dynamic balance of soil microbial communities. Therefore,it is necessary to optimize the application of P fertilizer in the entire crop rotation system to promote the activation and release of soil phosphorus,thereby reducing the amount of P fertilizer and improving its recovery rate.