长期定位施肥对玉米生育期内土壤酶活性的影响

以吉林省公主岭市的国家黑土肥力和肥料效益长期定位试验为平台,对2014年土样进行酶活性测定和分析,探讨长期定位施肥条件下玉米生育期内土壤酶活性的动态变化。结果表明,不同定位施肥处理过氧化氢酶、脲酶和磷酸酶活性在玉米生育期内呈大致相同的变化规律,从苗期至拔节期上升,在拔节期出现峰值;随后下降,至灌浆期酶活性最低,收获后酶活性出现回升。蔗糖酶活性的动态变化与以上3种酶活略有不同,从苗期至开花期升高,开花期至收获后期呈下降趋势。在玉米相同生育期内不同施肥处理间比较,土壤中脲酶、磷酸酶和蔗糖酶活性变化规律为有机肥+化肥(NPK+1.5M1)有机肥+化肥(NPK+M2)有机肥+化肥(NPK+M1)有机肥+化肥+轮作(NPK+M1+R)化肥+秸秆还田(NPK+S)单施化肥(NPK)CK。长期有机肥配施化肥和秸秆配施化肥处理对酶活性的促进效果比氮磷钾处理明显。

Effects of Long-term Fertilization on Soil Enzyme Activities in Maize Growth Period

In order to investigate the dynamic changes of soil enzyme activities during growth of maize, en-zyme activities of 2014 soil samples were investigated based on the long-term experiment of national black soil and fertilizer efficiency in Gongzhuling city. The results showed that the activities of hydrogen peroxides, urease and phosphatase showed changes in roughly the same during maize growth period among different fertilization treat-ments. From seedling to jointing stage rising, peaked at the jointing stage and then decreasing to the lowest at grain filling stage, occurring a rising trend after that the dynamic changes trend of soil enzyme activity is same in maize growth period, namely harvest. Sucrase activity increased from seedling to blossom period, blossom period reached the peak, blossom stage to harvesting stage showed a downward trend. At the same growth period of maize in differ-ent fertilization treatments, the activity of soil urease, phosphatase and sucrase change regularity was: NPK + 1.5M1 > NPK+M2 > NPK+M1 > NPK+M1+R > NPK+S > CK > NPK. Hydrogen peroxides activity regularity in maize growth period was not so obvious. In general, compared with single application of chemical fertilizer treat-ment, the promoting effects of long term organic fertilizer with chemical fertilizer and straw with fertilizer on enzyme activity were more significantly.