湖北梁子湖湿地土壤养分的分布特征和相关性分析

Distributi on Soil Nutrients and Correlation Analysis in Lake Liangzi Wetlands,Hubei Province

对湖北梁子湖农业湿地土壤有机质、N、P、K的分布特征进行了研究.结果表明,土壤表层有机质含量在24.203-56.815g/kg之间,TN、TP、TK分别为1.385-2.911g/kg、0.406-0.523g/kg和14.68-26.77g/kg.五类土壤中有机质、TN、TP、TK在水平分布上是随地形部位升高(地下水位降低)而降低,即从沼泽型→潜育型→侧渗型→潴育型→淹育型渐次降低.土壤剖面中,有机质、TN、TP、TK从表层到底层逐渐降低,仅在淹育型土壤中TK是从上向下逐渐升高.侧渗型水田由于湖水脉动漂洗作用使剖面底层的有机质、TN、TP、TK都低于其它四类土壤.土壤表层中速效N、P分布特征与TN、TP相似,但速效K的变异较大.土壤表层中有机质、TN、TP、TK之间有良好的相关性,而剖面中有机质与TN也高度相关.此外,沼泽型土壤有机质与TK及TN与TK显著相关,而淹育型土壤剖面中TP与TK显著负相关.

The wetlands in Lake Liangzi in the middle reaches of Yangtse River were investigaged in autumn, after late rice harvest in 2003. Five typical paddy soil were identified, i. e. submergic, hgdroaric, bleached, gleyed and swamp paddy soils. Soil profiles as well as samples from different horizons were collected for measuring organic matter, TN,TP, TK and available N, P,K etc. It was found that the content of organic matter, TN, TP, TK were 24.203-56. 815 g/kg, 1.385-2.911 g/kg,0.406-0.523 g/ kg and 14.68 -26.77 g/kg, respectively. The organic matter, TN,TP,TK were increased in paddy soils with the drop of topographical location and the ascending of ground-water level in the plow layer. The organic matter, TN, TP and TK were decreased form plow layer to subsoil in five paddy soil profile except that TK was increased from plow layer to subsoil in submergic paddy soil profile. In addition, available N of plow layer in swamp paddy soil was lower than gleyed paddy soil, but higher than other three paddy soils. Available N of plow layer has similar variation with TN in other four paddy soils whereas available P of plow layer was lowest in swamp paddy soil. Correlation analysis revealed that the organic matter, TN,TP,TK have significant correlation in plow layer with correlation coefficient of 0.957, 0.953 and 0. 825,respectively. At swamp paddy soil profile, the correlations between organic matter with TK, and between TN with TK were also significant, with correlation coefficients of 0.772 and 0. 674,respectively. However, at sumergic paddy soil profile the TP with TK were negatively correlated(R = -0.675).