杉木连栽林地土壤生化特性及土壤肥力的研究

Studies on the Enztme Activities Ans Fertiliestiof Soils in Cinhinese-fir Repeated Plantation Woodland

本文通过对不同连栽代数的杉木林地土壤生化特性及化学性状的系统研究,探讨土壤酶活性及土壤化学性状随着杉木连栽代数的增加变化趋势;土壤酶活性与土壤养分含量之间的相关性。 土壤的营养元素含量随着连栽代数的增加,表现出明显的下降趋势,二代比一代下降了10—20％,三代比一代下降40—50％,尤其以有机质最为显著;土壤生化活性除个别酶外,大多数酶活性表现为一代>二代,一代>三代,二代比一代下降5—10％,三代比一代下降40—50％,显示出连栽后地力下降和生化性降低的趋势。

In this paper, some soil biochemical activities and some chemical properties of the soils in the Chinese fir repeated plantation woodland were studied. The results were as follows, ( 1 )With the increase of the rotation of Chinese-fir replanted, the enzyme activities (except polyphenol oxidase ) and the nutrient contents of the replanting soil were decreasing markly, a phenomenon called 'Exhaustion of soil and deterioration of environment' appear, finally replantation of Chinese-fir caused decrease in its productivity. ( 2 ) It was found that polyphenol oxidase of soil in the Chinese-fir replanting woodland possessed more intensive activity. It would be possible for certain polyphenol compound to accumulate to generate toxicists of soils which would be another cause of the decrease in the productivity of forest stand. ( 3 )Statistical test indicated significant positive correlations between the enzyme activities of Catalase, Urease, Protease, Neutral-phoophatase, Acid-phosphatase, Invertase, Peroxidase (except polyphenol oxidase)and soil fertility. These correlation coefficients allreached the least significant levels ( P00.01 or 0.05 ) .So activities of soil enzyme could be used as an important index for evaluation of soil fertility.