江苏省如皋市土壤中量元素含量有效性评价

Availability Assessment of Medium Elements Contents in Soils of Rugao, Jiangsu

为平衡施肥提供依据,本文应用GPS定位技术采集了江苏省如皋市290个代表性土样,并对土样中钙、镁、硫、硅4种中量元素有效态含量进行了检测和评价。结果显示,全市土壤交换性钙、交换性镁、有效硫和有效硅平均含量分别为4 570、403、26和144 mg/kg。如皋市土壤交换性钙、镁含量丰富,但在各土系土壤间分布不均。有效硫和有效硅同时存在缺乏和过高现象。整体来看,有近1%的土壤缺硅,约14%的土壤缺硫。土壤交换性镁和有效硅的含量为中等变异,交换性钙和有效硫的含量属于高度变异。相关分析显示,4种中量元素有效性与土壤pH、有机质、全氮、有效磷和速效钾含量存在不同程度的相关性。如皋市土壤中量元素有效性不仅与成土母质关系密切,同时受土壤理化性状以及肥料施用的重要影响。今后中量元素肥料的施用应考虑多种因素,以实现平衡施肥。

In order to provide basis for balanced fertilization, a total of 290 topsoil samples in Rugao were collected using GPS positioning technology and the available contents of four medium elements of calcium, magnesium, sulfur and silicon in soils were analyzed and assessed. The results showed that the average contents of exchangeable calcium, exchangeable magnesium, available sulfur and available silicon in soils were 4 570, 403, 26 and 144mg/kg, respectively. On the whole the contents of exchangeable calcium and exchangeable magnesium were abundant but they were not evenly distributed. Available sulfur and available silicon were both deficient and excessive. Nearly 1% of the samples were deficient in silicon, and about 14% of the samples were deficient in sulfur. According to relevant literature, the contents of exchangeable magnesium and available silicon were medium variation, and the contents of exchangeable calcium and available sulfur were great variation. The correlation analysis showed that there were different correlations between the availability of four medium elements and soil pH, organic matter, total nitrogen, available phosphorus and available potassium. It can be concluded that due to the influences of soil parent material, physicochemical properties, fertilization and agricultural utilization patterns, the content variabilities of soil medium elements were large in the whole city. In the future, more attentions should be paid to the reasonable application of medium element fertilizers to realize balanced fertilization.