为了进一步探明红壤旱土磷素微生物固持的机理,采用室内模拟培养试验研究了微生物类群对红壤旱土团聚体(0.2～2mm)磷素转化的作用.结果表明:在培养90d期间,添加稻草处理能显著提高红壤旱土团聚体的微生物生物量碳、生物量磷、提取磷(Olsen法)和有机磷的含量.在培养前期(5～30d),与添加稻草处理比较,稻草+真菌抑制剂(放线菌酮)、稻草+细菌抑制剂(四环素+链霉素硫酸盐)处理团聚体微生物生物量碳含量分别降低10.5%～31.8%和6.8%～11.6%,前者的降低幅度显著大于后者(P<0.01),此后加入抑菌剂处理团聚体微生物生物量碳基本保持稳定.添加细菌抑制剂处理团聚体微生物生物量磷含量在培养5～20d期间比加真菌抑制剂处理高10.0%～28.8%,差异显著(P<0.01).表明真菌和细菌均参与红壤旱土团聚体磷素的固持,但真菌的作用明显大于细菌. In order to further ascertain the mechanism of phosphorus retention in red soils, the effect of microbial population on the conversion of phosphorus (0.2 ~ 2mm) in the red soil dry matter aggregates (0.2 ~ 2mm) was studied by indoor simulated cultivation experiments.The results showed that during the 90d incubation, The treatment could significantly increase microbial biomass carbon, biomass phosphorus, Olsen method and organic phosphorus content of the aggregates of red soil dry matter in the early stage of culture (5 ~ 30d), straw + fungi inhibition The biomass carbon content of aggregates decreased by 10.5% ~ 31.8% and 6.8% ~ 11.6%, respectively, with the decrease of the former being significantly greater than that of the latter by the mixture of cycloheximide, cycloheximide and actinomycetes (tetracycline + streptomycin sulfate) (P <0.01), and the microbial biomass carbon of the aggregates remained stable after the addition of bacteriostatic agents. Bacterial inhibitors were used to treat the aggregates. The biomass phosphorus content was 10.0 higher than that of fungicide inhibitors during 5-20 days of culture % ~ 28.8%, the difference was significant (P <0.01), indicating that both fungi and bacteria are involved in the retention of phosphorus in the dry matter aggregates in the red soil, but the effect of the fungi is obviously greater than that of the bacteria.