不同施肥黑土微生物量氮变化特征及相关因素

研究长期施用两种不同量有机肥(M2、M4)和化肥(NPK)的黑土微生物量N在作物生长季的变化特征．结果表明，施用有机肥黑土微生物量N显著高于施用化肥(NPK)和不施肥(CK)，微生物量N季节波动小．微生物量N为M4 25．52～239．12mg·kg^-1，M2 10．40～94．31mg·kg^-1．NPK6．27～87．04mg·kg^-1，CK9．15～69．81mg·kg^-1，同一处理最大值与最小值相差7～14倍．M2、NPK处理微生物量N最大值出现在抽雄吐丝期，M4处理最大值出现在拔节期，CK处理最大值出现在播种期；不同处理微生物量N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N的动态变化与极少数黑土生物、理化特性指标动态变化显著相关；微生物量N与黑土生物、理化特性，植物氮、磷、钾有极显著的正相关关系，与土壤含水量、籽粒粗蛋白含量呈显著正相关关系．

Dynamics of microbial biomass N in different fertilized black soil and its related factors

This paper studied the dynamics of microbial biomass N in a black soil long-term fertilized with farmyard manure (M2 and M4) and chemical fertilizer (NPK) during crop growth season. The results showed that the soil microbial biomass N was 25.52-239.12 mg x kg(-1) in M4, 10.40-94.31 mg x kg(-1) in M2, 6.27-87.04 mg x kg(-1) in NPK, and 9.15-69.81 mg x kg(-1) in CK. In same treatment, the highest value was 7-14 times higher than the lowest value. Treatments NPK and M2 had the highest value of microbial biomass N at reproductive growth stage, while M4 and CK had it at vegetative growth stage. The significant difference of soil microbial biomass N caused by different treatments was not changed with plant growth stages. The dynamics of soil microbial biomass N had a significant correlation some soil biological, physical and chemical properties. A significant positive correlation was found between soil microbial biomass N and soil biological, physical and chemical properties, plant N, P and K contents, soil moisture, and grain crude protein.