Effects of Application of Fertilization on Culturable Microorganisms and Microbial Biomass Phosphorus in Upland and Paddy Soils of Red Earth Region

An upland and paddy soil samples of red earth region were collected from various treatments of a long-term fertilization experiment in Hunan, China.And the culturable bacteria, fungi and amount of microbial biomass phosphorus (MB-P) were analyzed.The results indicated that combined application of straw and chemical fertilizers (NPK-Str) significantly increased the amount of culturable fungi and MB-P compared with the treatment of no fertilization (CK) and chemical fertilizers (NPK) in upland soils.Whereas there's no significant difference of culturable bacteria among the treatment of CK、NPK and NPK-Str in upland soils.It suggested that fungi possibly played a key role in the phosphorus transformation of upland soils amended with rice straw.However, combined application of straw and chemical fertilizers with addition of astragalus (NPK-Str-GM) significantly increased the amount of culturable fungi, bacteria and MB-P in paddy soils, especially, the enhancement level of culturable bacteria was much higher than that of fungi, in comparison with the treatment of CK and NPK.Consequently, this study demonstrates that bacterial and fungi likely play different roles on microbial biomass P in upland and paddy soils.That is bacteria may contribute on the MB-P which application of rice straw and organic green manure (astragalus) in paddy soils, however, fungi only play a majorrole in upland soil with the application of rice straw.