有机物料影响下土壤溶液铜形态及其有效性研究

Forms and Availability of Copper in Solution of Soil Containing Organic Materials

研究了盆栽种稻条件下,有机物料对土壤水溶性铜、易解离态铜和可解离态铜含量变化的影响及其与水稻吸铜量之间的关系。结果表明,在分蘖期,当不添加外源铜时,猪粪和泥炭均降低了潮土水溶性铜含量,但没有降低红壤水溶性铜含量。两种有机物料均降低水溶性铜的可解离程度。当添加外源铜时,两种有机物料均显著降低了水溶性铜浓度。到成熟期,在不添加外源铜的情况下,两种有机物料不同程度地提高了水溶性铜含量,但在添加外源铜的情况下,则仍然降低了水溶性铜含量。pH和DOC是影响土壤铜溶解度及形态的主要因素,但在不同条件下,二者的影响程度不同。土壤溶液中3种形态铜含量均与水稻吸铜量呈显著正相关。

The effect of two organic materials, pig manure and peat, on total water soluble Cu (WS-Cu), easily labile Cu (EI-Cu) and labile Cu (L-Cu) as well as Cu uptaken by rice was studied with pot experiments. At the tillering stage, the concentration of WS-Cu in the treatments of fluvo-aquic soil without adding Cu was decreased by the treatments with pig manure and peat, respectively. However, the concentration of WS-Cu from the treatment of red soil was not decreased apparently. The ratios of EI-Cu to WS-Cu (B/A) and that of L-Cu to WS-Cu (C/A) were lowered by the two organic materials. For the treatment with addition of Cu, the WS-Cu was decreased in the two organic materials. At the mature stage, the two organic materials increased the WS-Cu under the conditions without adding Cu whereas decreased the WS-Cu under the conditions with adding Cu. pH and DOC were found as the main factors in controlling the solubility and the forms of Cu in the soil with varying significance under different conditions. The uptake of Cu by rice root showed significantly positive correlation with WS-Cu, EL-Cu and L-Cu.