紫色土区土壤氮元素特征研究

对紫色土区选择不同坡位(坡顶、坡中、坡底)不同土地利用方式(耕地、林地、园地和撂荒草地)土壤的全氮和速效氮含量进行了分析,结果发现:土壤氮含量分布受坡位影响严重,通常坡底全氮及速效氮含量最高,坡中最低;土壤氮含量分布受土地利用影响严重,通常是林地全氮及速效氮含量最高而耕地最低;研究区4种土地利用方式下,C/N范围在7.3～13.9之间;土壤全氮含量与土壤容重、黏粒含量、全氮、速效氮、全钾以及速效钾含量相关性显著。

Characteristics of Nitrogen Element in the Soil at Purple Lands

The study,based on the different slope position (top,middle,bottom) and land use (farmland,woodland, garden land and abandoned grassland),analyzed the total nitrogen and available nitrogen in the soil. The results showed: (i)the nitrogen content is influenced by the slope position,generally,the content of total nitrogen and available nitrogen is the highest in the bottom of slope,and the lowest content occurred in the middle of slope; (ii)the content of nitrogen is influenced by the land use,usually the content of total and available nitrogen in the woodland is the highest,and that in the farmland is the lowest;(iii)the ratio between carbon and total nitrogen is concentrated on 7.3～13.9 under different land use; (iv)the content of total nitrogen is correlated significantly with the bulk density,clay content,available nitrogen,total potassium and available potassium.