关键词: 硝化抑制剂, 双氰胺, 作用机理, 抑制效果, 氮肥利用率

Abstract: The distribution characteristics of soil available K and its correlations with plant species diversity in the forest ecosystem of Mt.Jinyun are studied in this paper.The results are as follows:①Except for shrub-grassland,the content of available K in soil profiles under different communities has an evident gradient,i.e.,A(humus horizon)>B(deposited horizon)>C(parent material horizon).②The content of available K in A and B horizons gradually increases along the successional direction,i.e.,shrub-grassland<Pinus massoniana pure forest<P.massoniana-Symplocos setchuensis mixed forest<evergreen broadleaved forest.This law does not exist in the C horizons.③Different degrees of correlations exist between the content of soil available K and plant species diversity.The correlation between species diversities of trees and grasses and the content of available K in A and B horizons is the most significant.

Key words: nitrification inhibitor, dicyandiamide (DCD), inhibition mechanism, inhibition effect, nitrogen fertilizer efficiency.