喀斯特山地不同土地利用方式土壤养分特征研究

Characteristics of Soil Nutrient under Different Land Use Types in Karst Mountain Area

不同的土地利用方式影响着土壤的养分特征及土壤质量。对重庆市南川区灌草丛、人工林、果园、旱地、水田、撂荒地6种不同土地利用方式下土壤养分的研究表明:不同土地利用方式间土壤养分存在一定的差异,变化规律也不一致。6种土地利用方式下的土壤有机质、全氮、速效氮、速效磷、速效钾都呈现表聚现象,且有机质、全氮、速效氮都随深度的增加而递减,但全磷和全钾含量并无明显的变化规律。6种土地利用方式各土壤养分指标含量排序各异,退耕后土壤部分养分含量仍较低,初步认为该区土壤养分受人为影响较严重,退耕后土壤恢复能力还较差。

The land use types affect the nutrient feature and the texture of soil.It studies the soil nutrients under 6 different land use types including shrub-grassland,plantation,orchard,dry land,paddy fields and abandoned land in Nanchuan District of Chongqing.The outcomes show that the soil nutrient contents are difference under different land use types and the variation laws are also different.The contents of organic matter,total nitrogen,available nitrogen,available phosphorous and available potassium of soil under the 6 different land use types all show accumulation in surface soil,and the contents of organic matter,total nitrogen and available nitrogen decrease progressively along with the increase of the depth,but the contents of total phosphorous and total potassium do not show significant variation law.The sequences of indexes of soil nutrient content under 6 different land use types are different and part of soil nutrient contents are still low after returning farmland.It initially considers that the soil nutrient contents are seriously affected by human and the capability of soil restoration after returning farmland is lower.