菜园土壤中的铜及其与土壤有机碳的关系

Copper Situation of Vegetable Garden Soils and Its Relation to Soil Organic Carbon

通过野外调查与室内分析相结合的方法研究了杭州市郊主要菜园土壤中铜的状况 ,并对其与土壤有机碳的关系作了探讨。取样分析结果表明 ,调查区域菜园土壤全铜含量在 4 3×1 0 - 6 ～ 2 0 5 5× 1 0 - 6 之间 ,平均为 ( 43 6± 3 6 7)× 1 0 - 6 ,有效铜含量在 0 1 7× 1 0 - 6 ～ 6 1 8× 1 0 - 6之间 ,平均为 ( 2 70± 1 4 6)× 1 0 - 6 。同时还发现 ,菜园土壤有效铜含量与全铜含量呈极显著正相关 ,相关系数为 0 71 7 (n =4 5,P =0 0 1 ,下同 ) ,据此认为菜园土壤有效铜的供给是以全铜量为基础的。相关分析还得出 ,全铜含量与总有机碳和易氧化碳含量均呈极显著正相关 ,相关系数分别为 0 695 和 0 594 ;有效铜含量也与总有机碳和易化有机碳含量呈极显著正相关 ,相关系数分别为 0 666 和 0 557 ,这表明施用有机肥料可能是菜园土壤铜营养的重要来源之一。另外 ,菜园土壤铜的有效性也有随土壤总有机碳和易氧化有机碳含量的提高而增大的趋势 ,这对一般情况下提高土壤的供铜强度是有益的。但是 ,倘若土壤中已积累了过量的铜 ,则有可能加剧铜的毒害 ,蔬菜生产和菜园土壤管理中都应予以足够的重视。

Cu situation of vegetable garden soils and its relation to soil organic carbon were investigated. The results showed that the total Cu content of vegetable garden soils in the survey area ranged 4 3×10 -6 ～205 5×10 -6 with an average value as 43 6×10 -6 ±36 7×10 -6 and the available Cu content range 10 17×10 -6 ～6 18×10 -6 with an average value as 2 70×10 -6 ±1 46×10 -6 .It was found that there was a significant correlation between the available Cu content and the total Cu content with the correlative coefficient of 0 717( n =45, P =0 01),which implying that the supply of available Cu in vegetable garden soils is based on the total Cu content. It can also be obtained that the total Cu content of the vegetable garden soil was significantly correlative to the content of TOC (total organic carbon) and EOOC(easily oxidized organic carbon)with the correlative coefficients of 0 695 and 0 594( n =45, P =0 01),and so was the available Cu content with the correlative coefficients of 0 666 and 0 557( n =45, P =0 01)It meant that organic manure may be one of the main sources of Cu nutrients of vegetable garden soils. The availability of Cu in vegetable garden soils tends to rise with the increases of content of TOC and EOOC, which is valuable for enhancing the intensity of Cu supply, and also effective to increase the Cu toxicity if there is excessive Cu accumulated in the soils, as well as noticeable in both the management of vegetable garden soils and the vegetable production.