The Relationship Of Soil Enzyme Activities Between Soil Nutrients In A Long-Term Continuous Planting Eucalyptus Plantation

The soil enzyme activities (include urease, acid phosphatase,sucrase, catalase) and soil fertility factors (include soil moisture content,pH,total nitrogen,total phosphorus,hydrolyze nitrogen,available phosphorus,available potassium and organic matter)was had been researched by seasonality and used for assess soil fertility quality and soil degradation index in a long-term continuous planting eucalyptus plantation in Dongmen town,Ggangxi.Path analysis and correlation analysis were used for discuss the relationship between soil enzyme activities and soil fertility factors.The results of the study are as follows:(1) The changing trends of soil enzyme activities and mainly fertility factors in different sample plot were as follow, urease:FH(the sample plot which is only have frutex and herb)> FR(the sample plot which planted eucalyptus first time)>TR(the sample plot which is the second bud of FR)>SR(the sample plot which is the first bud of FR); acid phosphatase:FH> FR>SR>TR; sucrases and catalase:FH>SR>FR>TR. soil moisture conten、pH and hydrolyze nitrogen:FH>FR>SR>TR; total phosphorus:FH>TR>FR>SR;total nitrogen、 available phosphorus、 available potassium and organic matter:FH> FR> TR> SR.(2) The rule of seasonal change of soil enzyme activities in different smaple plot is the same.The changing trends of urease was:spring>autumn>summer>winter;the acid phosphatase and sucrase were:autumn>summer>pring>winter;the catalase was:summer>pring>winter>autumn;the soil moisture content was:autumn>summer>winter> pring;the pH was:winter>summer>autumn>pring;the total nitrogen was:summer> pring>autumn>winter;the total phosphorus was:summer>pring>autumn>winter;the hydrolyze nitrogen was:summer>pring>autumn>winter;the available phosphorus was: summer>pring>autumn>winter;the available potassium was:winter>autumn>pring>summer;the organic matter was:winter>pring>autumn>summer.(3) The correlation between urease and hydrolyze nitrogen、available potassium、 available phosphorus and organic matter were all extremely significant. The correlation between acid phosphatase and pH、available phosphorus and organic matter were all significant,and all so had extremely significant with soil moisture content and hydrolyze nitrogen.The correlation between sucrase and pH、hydrolyze nitrogen、available phosphorus and organic matter were all extremely significant. The correlation between catalase and pH、 vailable phosphorus and organic matter were all extremely significant, and all so had significant with soil moisture content.The first three factors which had important decision to soil enzyme activities were the interaction between hydrolyze nitrogen and organic matter,single action of hydrolyze nitrogen and organic matter.(4) In comparison with FH,we found the soil fertility quality in diffrent eucalyptus plantations were:FR>TR>SR;the soil degradation index were:SR>TR>FR. So a long-term continuous planting will cause the woodland soil fertility decline, but the decline is not increase with long-term continuous planting absolutely.Reasonable measures of management and operation can slow down the decline of soil fertility of eucalyptus plantation effectively.