不同肥力塿土、棕壤磷酸酶活性对土壤培养温度和含水量的响应

Soil phosphatase activity of loessial soil and brown earth with different fertility in response to culture temperature and soil moisture

为研究土壤培养温度,含水量和肥力差异对土壤磷酸酶活性的影响,采用室内培养,以不同肥力(CK、NPKM)长期定位试验土壤(塿土、棕壤)为供试土壤,分别设定3个培养温度(-20、4和25℃)和3个水分处理(10%、25%和40%),避光培养2个月,测定土壤磷酸酶活性变化。结果表明:1)土壤磷酸酶活性变化对培养温度响应不敏感;2)培养的土壤含水量显著影响土壤磷酸酶活性变化,且与土壤肥力关系密切。对于含水量25%处理,低肥力CK在土壤含水量为40%时,磷酸酶显著增加50%以上;3)土壤有机磷浓度与土壤磷酸酶活性呈正相关,相同土壤有机磷浓度时,棕壤的磷酸酶活性始终大于塿土。因此,土壤水分是影响低肥力土壤有机磷积累-矿化动态平衡的重要因素,而有机磷浓度是决定土壤磷酸酶活性主要因素之一。

In order to study the response of soil phosphatase activity to cultural temperature,soil moisture and soil fertility,a laboratory culture experiment was conducted with two different fertility soils from two long-term fertilizer experiments（soil types：loessial soil and brown earth;fertilizer treatments：CK and NPKM）,and soil cultured in an incubator under three culture temperature（-20,4,25 ℃）and three soil moisture levels（10% ,25% ,40% ）.Soil phosphatase activity of soils was determined after two months cultivating.The results showed that：1）Soil culture temperature has less effect on soil phosphatase activity;2）Soil moisture significantly changed soil phosphatase activity,but it was closely related to soil fertility.For low fertility soil（CK）,soil phosphatase activity with 40% soil moisture increased more than 50% in contrast to treatment at 25% ;3）There was a positive correlation between soil organic phosphorus concentration and soil phosphatase activity.Soil phosphatase activity of brown earth treatments was always higher than loessial soil treatments at the same soil organic phosphorus level.In conclusion,soil moisture significantly affected the balance between accumulation and mineralization of soil organic phosphorus in low fertility soil,and soil organic phosphorus concentration was one of determining factors of soil phosphatase activity.