长期施用化肥对红壤性水稻土中微生物生物量、活性及群落结构的影响

利用化肥长期定位试验,研究了施肥对土壤微生物生物量、活性及其群落结构的影响.结果表明:与不施肥相比,长期施用化肥不仅增加了土壤微生物生物量,而且导致了土壤微生物群落结构的分异.其中,有机无机配施处理和2倍NPK配施处理显著提高了土壤有机质含量、全N含量、土壤微生物生物量和土壤微生物活性.NPK均衡施肥处理对土壤有机质、土壤微生物生物量及其活性的影响小于非均衡施肥的处理(NP、NK、N、P、K),适当增施K肥有利于提高土壤微生物中真菌的比例.

Effects of Long-Term Chemical Fertilization on Soil Microbial Biomass, Activity and Community in Paddy Soil in Red Soil Region of China

Effects of long-term chemical fertilization on soil microbial biomass, activity and community of the paddy soils were studied by a long-term fertilization experiment setup in 1981. The experiment has 9 treatments, i.e. CK (no fertilization), N, P, K, NP, NK, NPK (different combination of N, P, and K), 2NPK (double NPK application rate) and NPKOM (NPK plus organic manure). Results showed that fertilizer application increased soil microbial biomass, and led to diversion of soil microbial community as compared with CK. Both the soil microbial biomass and microbial activity increased in Treatment NPKOM due to the increase in soil organic matter and total nitrogen. However, the soil microbial biomass and activity were depressed in Treatment NPK, balanced fertilization, as compared with other chemical fertilization treatments (NP, NK, N, P and K). The ergosterol data showed that the proportion of fungi in soil microbial community was increased in Treatments K and NK. The results suggested that chemical fertilization may increase soil microbial properties through changing the carbon input.