不同水肥条件对土壤酶活性的影响

为探讨不同施肥处理和水分条件对土壤酶活性的影响和土壤酶活性的短期变化规律,设置了不施肥(CK)、化肥(F)、有机肥(M)和有机肥+化肥(FM)等4种不同施肥处理和2种水分状况(田间持水量的70%和90%)的室内培养试验,对不同时间土壤脲酶、过氧化氢酶、蔗糖酶和碱性磷酸酶活性进行了测定分析。结果表明,培养过程中,不同施肥处理土壤脲酶活性呈现先升高后降低的趋势;土壤过氧化氢酶活性呈现先升高—降低—再升高—再降低的趋势;土壤碱性磷酸酶活性则呈逐渐降低的趋势;土壤蔗糖酶活性在整个培养过程处于一种波动变化。与CK相比,M和FM处理能够显著提高土壤脲酶、过氧化氢酶和碱性磷酸酶活性,单施化肥降低这些酶的活性。培养前期,M和FM处理降低土壤蔗糖酶活性,在后期提高其活性;单施化肥在一定程度上提高土壤蔗糖酶活性。与田间持水量为70%相比,过高的田间持水量会显著抑制土壤脲酶、过氧化氢酶和碱性磷酸酶活性。

Effects of Different Fertilizer Treatments and Water Regimes on Soil Enzyme Activities

The culture experiment was carried out over 63 days to investigate the effects of different fertilizer treatments and water regimes on soil enzyme activities.There were four fertilizer treatments including the control(CK),only chemical fertilizers(F),manure(M) and combined application of chemical fertilizers and manure(FM).Two levels of soil water contents were set which were well watered at 70% of the field water capacity(FWC),and water-surplus at 90%.The results indicated that soil urease activity under different treatments increased at first and then decreased;the activity of soil alkaline phosphatase showed the trend of decreasing gradually.The activities of soil catalase and saccharase had the fluctuant changes during culture.The activities of soil urease and alkaline phosphatase increased significantly in the M and FM treated soils compared with CK.At the prophase of culture,soil saccharase activity was lower in M and FM treated soil than that in CK,while increased at the late stage.Using only chemical fertilizer could increase the activity of soil saccharase to a certain degree.Compared with 70% of field water capacity,the activities of soil urease,catalase and alkaline phosphatase could be restrained under surplus water.