东北黑土区不同耕作方式土壤养分与酶活性的时空变化

通过田间试验研究了东北黑土区玉米不同耕作方式的土壤养分与酶活性的时空变化规律.结果表明,整个生育期不同处理在各个土层均有较高的碱解氮含量,而在播种前常规耕作高于宽窄行,玉米生长中期则是宽窄行高于常规耕作,收获后各处理含量水平基本一致.有效磷不同处理均表现出养分表聚现象,且宽窄行在各个生育期的不同土层内均高于常规耕作.速效钾含量随着土层的加深降低不十分明显,处理间没有表现出明显的差异,体现了钾素养分移动性大的特点.玉米生长关键期的全量氮、磷、钾变化幅度不大,处理问含量水平一致;有机质含量在2%～3%之间;pH值不同处理均随着土层的加深逐渐升高的趋势,说明不同的耕作措施都有促进土壤表层酸化的现象.不同耕作方式土壤酶活性在整个生育期变化趋势相同,无明显差异.

Effect of Tillage Form on the Soil Nutrient and Enzyme Activities of Black Soil Area at Northeast China

Field experiment was carried out in this study to investigate the effect of tillage form on the soil nutrient and enzyme activities of in the maize rhizosphere at black soil area of northeast China.In the normal rows,higher and lower NH_4~+-N was measured at before sowing and middle of cultivation,respectively.While,there was no significant differences after harvest.Throughout the study,assembled available phosphorus was found at both treatment and relatively higher available phosphorus was measured in the wide-nar-rows row at each soil layers compared to normal rows.For potassium content,a minor change was found at each layer in both applications and no significant differences were found between the two applications.As well as,there was minor changes were investigated in the total nitrogen,phosphorous and potassium during the main growth period at each application.Organic matter content of rhizosphere was maintained at 2%～3%at each applications.However,pH value was positively correlated with the soil depth which demon-strates that both applications may contribute to soil acidification.Same trend was found in both applications and no significant differences were found between the applications.The results indicate the potential widenarrow rows application in maize cultivation.