| This article is based on the 'N, P, K long-term fertilizer'field experiment on a calcareous purple paddy soil which was set up in 1982 in Suining City, Sichuan province by the Soil and Fertilizer Institute of Sichuan Academy of Agricultural Sciences, the influence of different fertilizer treatments including M, MN, MNP, MNPK, CK, N, NP and NPK fertilizer on the soil nutrition, the number of soil fungi, soil fungi biomass and the genentic characteristics. And the influence of different fertilizer treatments on the arbuscular mycorrhizal fungi(AMF). The results were listed as following,After 20 years of fertilization, the soil PH descreased, The pH values under 8 different fertilizer treatments were among 7.50-8.24. Compared to the chemical fertilizer treatments (CF), CF with farmyard manure (M) lead to a higher content of soil organic matter, available N, P. but had little impact on soil total N and available K. Amended with NPK and NPKM could result higher or even the highest amount of soil organic matter, available N, P and K, while the N, NP, M, MN, MPN fertilizer treatment, soil nutrient content is relatively low.The results of the number and biomass of soil fungi showed that the treatments receiving any fertilizer application tended to increase the number and biomass of soil fungi compared with the control (no fertilizer treatment). The application of manure was increased more than the chemical fertilizers. Among the 8 fertilizer treatments, the highest amounts and biomass were in the soil amended with NPKM, and the lowest amounts and biomass were the control (no fertilizer treatment).Soil fungi community structure was analyzed by PCR-DGGE targeting eubacterial 16S rRNA genes. Different fertilizer treatments of soil fungal community structure had certain changes. Generally, higher diversity of the soil fungal community was found in soil amended with farmyard manure plus mineral fertilizer than in other fertilizer treatments. Some specific band emerged in the soil amended with farmyard manure. The highest diversity of fungal communities was found in the NPKM treated soil.The result of the influence of long-term located fertilization on the AMF showed:there only 17 species of AMF were identified from the soil,12 species belong to Glomus, which was 70.5 percent of isolated species.3 species belong to Acaulospora, which was 17.6 percent of isolated species.1 species belong to Archaeospora and 1 species belong to Entrophospora, which each was 5.9 percent of isolated species. The study of the infection to the host showed that the infection was very low. Either wheat or rice soil, the highest rate of infection was the non-fertilizer treatment (CK), in others the infection rates are very low or no infection. And the available P in the soil directly affects the growth and development of AMF and host plant inoculation effect.The DGGE profiles of AMF showed that the diversity of AMF was effected by different fertilization ways; Applied N only maked the biggest Shannon index, and it was better than that from applying farmyard manure only in paddy soil and wheat-planted soil; Shannon index become smaller under some certain scale between farmyard manure and inorganic substances; cluster analysis showed that farmyard manure and inorganic substances had obvious different effect on AMF community and they both had effect on each other. The results of this investigation indicated that fertilization had an effect on community and distribution of AMF which had a wide influence on the community structure and genetic diversity.
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