施肥措施对不同母质发育的稻田生态系统土壤微生物量碳、氮的影响

以湖南省稻田土壤肥力监测点为基础，研究了稻田生态系统土壤微生物量碳、氮的特性.结果表明，不同施肥措施对不同地域和母质发育的稻田生态系统土壤微生物量碳、氮的影响程度不同.经过18年的不同施肥处理，不同母质发育的稻田生态系统土壤微生物量碳、氮的变化趋势基本一致，变化顺序为湖积物发育的水稻土>河流冲积物和第四纪红土发育的水稻土>石灰岩发育的水稻土>板页岩发育的水稻土.土壤微生物量碳为259.5～864.4 mg·kg^-1，土壤微生物量氮为8.7～70.7 mg·kg^-1.施肥可以明显提高稻田生态系统土壤微生物量碳、氮含量；有机肥是改善土壤微生物量碳、氮的主要基础物质，但以有机无机配合施用效果最好.与对照相比，施化肥和有机无机配施处理土壤微生物量碳、氮最大增量分别为407.6和59.2 mg·kg^-1，最大增长率分别为102.8%和514.8%.

Effects of fertilization on microbial biomass C and N in paddy soils derived from different parent materials.

Based on the monitoring of soil fertility, this paper studied the characteristics of microbial biomass C (MBC) and N (MBN) in paddy soils derived from different parent materials in Hunan Province. The results showed different fertilization systems had different effects on soil MBC and MBN. After 18 years fertilization, the MBC and MBN in different paddy soils had similar variation trend, with the sequence of paddy soil derived from lake sediment > from river alluvium and quaternary red earth > from limestone > from shale. Soil MBC content ranged from 259.5 to 864.4 mg x kg(-1), while MBN ranged from 8.7 to 70.7 mg x kg(-1). Fertilization could increase soil MBC and MBN markedly. Organic fertilizer was the main element for the promotion of soil MBC and MBN, and combined application of organic and inorganic fertilizers could obtain the greatest effect. The increment of soil MBC and MBN after applying inorganic fertilizer and its combination with organic fertilizer was 407.6 and 59.2 mg x kg(-1), in maximum, and the maximum increasing rate was 102.8% and 514.8%, respectively, compared with no fertilization.