土壤中植物有效锰的形态分级

Fractionation of Soil Manganese Forms to Plant Availability

用4种方法测定土壤有效态锰含量，并加以比较和评价，从而确定出最优的土壤有效锰测定方法。研究结果表明，采用一种顺序浸提的方法能比较准确地反映土壤的供锰状况，锰组分及其相应浸提剂为：易溶态锰（0.05 mol/L Ca(NO3)2提取）、弱吸附态锰（pH 8.5, CaDTPA-B4O7 ）、碳酸盐束缚态锰（石灰性土壤，用1.6 mol/L HNO3快速浸提）或专性吸附态锰（非石灰性土壤，pH 4.4，0.05 mol/L Ca(NO3)2 + 0.05 mol/L Cu(NO3)2提取）和氧化锰（pH 2.0，0.1 mol/L NH2OH(HCl）。由盆栽试验辣椒吸收的锰与土壤锰相关分析结果显示，易溶态锰是植物最易吸收的锰，其回归方程为：Y = -14.409 + 21.658 X，r =0.9938**（p≤0.01），Y为辣椒叶片锰含量，X为土壤易溶态锰浓度。

In order to get the best way to determine soil available Mn, four methods had been done and been compared with each other. The result of experiments indicated that a sequential-extraction procedure could quantitatively estimate those forms of Mn in soils of significance to plant Mn availability. The Mn fractions and their extractants were: readily soluble Mn - 0.05 mol/L Ca(NO3)2 ; weakly adsorbed Mn - pH 8.5, CaDTPA-B4O7 ; carbonate-bound Mn ( calcareous soils)-rapidly extraction with 1.6 mol/L HNO3; specifically adsorbed Mn ( noncalcareous soils) -0.05 mol/L Cu(NO3)2 in 0.05 mol/L Ca(NO3)2 , pH 4.4; and oxide Mn - pH 2.0, 0.1 mol/L NH2OH(HCl. It showed from the result of relationship analysis between Mn uptake by pepper in pot experiment and tested soil Mn forms that: readily soluble Mn was the most readily Mn uptake by plant. Multiple regression equation was given: Mn content in pepper leaves = -14.409 + 21.658 readily soluble Mn, r =0.9938** ( p≤0.01 ).