盐渍化对沙枣林土壤养分和酶活性的影响

Effects of Salinization on Soil Nutrients and Enzyme Activities in Elaeagnus Angustifolia Forest

以张掖市甘州区的三块盐渍化程度不同的沙枣林土壤为研究对象,分析了不同盐渍化土壤0~30cm土层的养分及土壤酶活性特征。结果表明:表层土壤有机碳及全氮含量随盐渍化水平升高而降低,随土层深度增加而降低;中度盐渍化与非盐渍化土壤C:N稳定且处全国正常水平,C:P、N:P略高于同区域土壤,养分限制为磷元素,盐土土壤C:N平衡被打破,高于全国平均值,盐渍化对氮元素含量的限制要高于碳元素;土壤过氧化氢酶、脲酶、蔗糖酶、碱性磷酸酶活性表现为随盐渍化程度升高降低的趋势,垂直分布上,整体呈随土壤深度增加而降低的趋势;四种酶活性均与土壤C:N呈极显著负相关,可以通过降低土壤含盐量和C:N的方式提高酶活性,进而提高土壤肥力。

Taking three pieces of sandy jujube forests with different salinization degrees in Ganzhou District of Zhangye City as the research object,the nutrient and soil enzyme activity characteristics of 0~30cm soil layer in different salinized soils were analyzed.The results show that the content of organic carbon and total nitrogen in the surface soil decreases with the increase of salinization level and decreases with the increase of soil depth;moderately salinized and non-salinized soil C:N is stable and is at a normal level in the country.C:P and N:P are slightly higher than the soil in the same region,the nutrient limit is phosphorus,and the C:N balance of saline soil is broken,which is higher than the national average.The limit of nitrogen content in salinization is higher than that of carbon;The activities of soil catalase,urease,sucrase,and alkaline phosphatase showed a tendency to decrease with the increase of salinization degree,and the vertical distribution generally showed a tendency to decrease with the increase of soil depth;Soil C:N has a very significant negative correlation,which can increase enzyme activity by reducing soil salt content and C:N,thereby improving soil fertility.