长期培肥黑土脱氢酶活性动态变化及其影响因素

对东北典型黑土区长期不同培肥黑土脱氢酶活性在作物生长季的动态变化进行研究。结果表明,施用有机肥,生长季黑土总体脱氢酶活性显著高于施用化肥和不施肥,其生长季脱氢酶活性保护容量在5.5 mg TPF/kg土.h以上,黑土总体脱氢酶活性施用高量有机肥>低量有机肥>不施肥>化肥,季节性变化波动性大。长期施用高量有机肥脱氢酶活性最大峰值出现在拔节期,施用低量有机肥、化肥和不施肥最大峰值出现在完熟期;长期施用不同数量和种类肥料所引起的黑土总体脱氢酶活性差异并未因玉米生长影响而改变,说明长期施用高量有机肥黑土微生物氧化活性能力增强,土壤自身调解和维持肥力能力增强。黑土脱氢酶活性的动态变化与绝大多数土壤生物、理化特性指标的动态变化没有显著的相关性;总体脱氢酶活性与多数土壤生物、理化特性因子、植物全磷、钾含量有极显著和显著正相关关系。

Dynamics of Dehydrogenase Activity of Black Soil Treated by Long-term Fertilization

The effect of long-term fertilization on soil dehydrogenase activity of typical black soil in Northeastern China was examined in this paper.The investigated soils were treated by farmyard manure,chemical NPK fertilizer and the changes of soil dehydrogenase activity were monitored during crop growing season.The results showed that a significant difference was found in soil dehydrogenase activity of black soil treated by farmyard duving growth period.In the farmyard manure treatment soil dehydrogenase activity were highly conserved over 5.5 mg TPF/kg·h with a high seasonal fluctuation.Soil dehydrogenase activity of average value in all treatments varied in the order M_4>M_2> CK > NPK.Dehydrogenase activity of soil by farmyard manure M_4 was the highest at Jointing stage,while M_2,NPK,CK at Complete ripeness stage.The significant difference of soil dehydrogenase activity induced by different amount and type of fertilizers applied was not changed by plant growth.The Significant correlations was hardly found between dynamic changes of soil dehydrogenase activity and soil biological,physical and chemical properties in plant growing season in all treatments.A significant positive correlations was found between soil dehydrogenase activity and soil biological,physical and chemical properties,P and K contents of plants in P<0.01and P<0.05.