有机物料和氮肥相互作用对微生物体氮的影响*

培养和田间试验表明，有机物料（作物茎叶和有机肥）和氮肥对土壤微生物体氮的影响有着显著的交互作用。交互作用的大小与有机物料和氮肥的种类有关，因面也与有效碳源和矿质氮的比例有关。有机物料与硝态氮的交互作用大，而与铵态氮的交互作用小，交者是后者的２．７倍，这种８差异与微生物对两种形态氮的固定不同有关，有机物料Ｃ／Ｎ比的影响表现为随着Ｃ／Ｎ比增大，交互作用增加，并且在有机物料分解前期的交互作用大于中、后期

Interation Between Organic Material and Nitrogen Fertilizer on Microbial Biomass Nitrogen

The laboratory incubation and field experiment show that there existed the significant interaction between organic material and nitrogen fertilizer on soil microbial biomass nitrogen. The interaction had relation with not only the types of organic materials and nitrogen fertilizers, but also the ratio of available carbon source to mineral nitrogen. The interaction between organic material and nitrate was larger than that between organic material and ammonium, the former was as much as 2.7 times of the latter. With the C/N ratio raising in organic material the interactions almost increased. The interaction in early period of organic materials being decomposed by microorganisms was larger than that in middle and later periods. The interaction was largest at the ratio of available carbon source (glucose-carbon) to mineral nitrogen in soils (including fertilizer-nitrogen) being 0.l, otherwise the interaction decreases.