长期培肥黑土微生物量磷动态变化及影响因素

长期采用两种不同量有机肥(M2、M4)、化肥(NPK)方式培肥黑土，研究微生物量P在作物生长季动态变化．结果表明。施用有机肥微生物量P显著高于施用化肥(NPK)和不施肥(CK)，微生物量P分别为M48．75～47．68mg·kg^-1，M2 3．02～37．16mg·kg^-1，NPK1．59～10．62mg·kg^-1，CK0．76～6．74mg·kg^-1之间，波动性较大．M4、M2处理微生物量P最大值出现在抽雄吐丝期，NPK、CK处理最大值出现在大喇叭口期；施肥数量和种类不同所引起的黑土微生物量P的差异并未因季节变化及玉米生育时期影响而明显改变．微生物量P的动态变化与绝大多数黑土生物、理化特性指标的动态变化没有显著的相关性；微生物量P与黑土生物、理化特性(除全钾外)，植物氮、磷、钾含量有极显著的正相关关系，与黑土含水量呈显著正相关关系．

Dynamics of microbial biomass P and its affecting factors in a long-term fertilized black soil

This paper studied the microbial biomass P in a long-term fertilized black soil. The soil was fertilized by farmyard manure (M2, M4) and chemical fertilizer (NPK), and the dynamics of soil microbial biomass P was monitored during crop growth season. The results showed that the microbial biomass P in different treatments was 8.75-47.68 mg x kg(-1) (M4), 3.02-37.16 mg x kg(-1) (M2), 1.59-10.62 mg x kg(-1) (NPK), and 0.76-6.74 mg x kg(-1) (CK). The microbial biomass P in M4 and M2 was the highest at reproductive growth stage, and that in NPK and CK was the highest at early growth stage. The significant difference of soil microbial biomass P induced by different amounts and types of fertilizer application was not varied with the period and stage of plant growth. In all treatments, no significant correlation was found between the dynamics of soil microbial biomass P and the soil biological, physical and chemical properties in plant growth period. Soil microbial biomass P had a very significant positive correlation with soil biological, physical and chemical properties (expect K), and a significant positive correlation with the N, P and K contents of plants and soil water content.