Effects of Site Preparation Contour Reverse-Slope Terrace on Soil Acidity-Alkalinity and Enzyme Activities in Typical Watershed of Central Yunnan
[Objective]This study is aimed to explore the effects of site preparation treatment contour reverse-slope terrace on the improvement and enzyme activities of acidified soil in slope farmland.[Method]The slope farmland soil in Yizhe River Basin with contour reverse-slope terrace treatment in central Yunnan was selected as a research area in this study(the original slope farmland without any treatment was selected as control).Following field investigation and sampling,the soil pH,exchange-able cations(Ca2+,Mg2+,K+,Na+,H+,Al3+ and Fe3+),cation exchange capacity(CEC),sucrase,ure-ase,phosphatase,catalase,protease,polyphenol oxidase and amylase were measured and statistically analyzed,to explore the characteristics of soil acidification and enzyme activity changes.[Result]The results showed that contour reverse-slope terrace treatment in slope farmland significantly reduced the contents of acidogenic cations(H+,Al3+,Fe3+)(P<0.05),with exchangeable H+ decreased by 20.00%,exchangeable Al3+ and exchangeable Fe3+ decreased by 25.64%and 69.29%,respectively.On the con-trary,when compared with control,the soil pH of slop farmland implemented with contour reverse-slope terrace was increased by 9.46%～13.25%,the exchangeable base ions contents of Ca2+,Mg2+,K+ and Na+ were increased by 11.14%-39.31%,3.59%-8.96%,7.89%-17.14%,and 3.35%-7.99%,respectively,and CEC were increased by 14.74%-21.33%(P<0.05).After the implementation of the treatments,the activities of soil urease,sucrose,protease,catalase,polyphenol oxidase and microbial biomass carbon and nitrogen were significantly increased by 6.43%-15.28%,7.00%-31.70%,38.56%-73.71%,8.01%-21.20%,7.08%-11.14%and 17.57%-31.48%(P<0.05),respectively,while phosphatase activ-ity was decreased significantly(P<0.05)by 38.00%-95.85%compared with that of untreated slope farm-land.The pH,exchangeable base ions and CEC contents were significantly and positively correlated with enzyme activities(P<0.01),while acidogenic cations were significantly and negatively correlated with enzyme activities(P<0.01).Two-way analysis of variance showed that the site preparation measures,acidification indicators(pH,exchangeable ions)and their interaction significantly influenced enzyme activities(P<0.05),and acidification indicators had the greatest contribution to enzyme activities.[Conclusion]The site preparation treatment contour reverse-slope terrace alleviated the soil acidification environment and enhanced the enzyme activity,which is of great significance for solving the soil acidifi-cation problem of slope farmland and improving the productivity of slope farmland in mountainous areas.
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NSTL
万方数据
维普
