木质素对土壤吸磷特性的影响

通过测定土壤对磷的等温吸收，研究了木质素对土壤吸磷特性的影响。结果表明：木质素能够使土壤对磷的吸收量减少；随着磷的初始浓度（C0）的增加，加木质素与不加木质素处理土壤对磷的吸收量差异增大，这种差异在不同土壤间明显不同；C0＝80mp／L（本试验设定的最大浓度）时，供试土壤对磷的吸收量减少率分别为：红壤10．04％，黄壤9．80％，紫色土31．30％。

Effects of Lignin on Soil's Phosphate Absorbability

Effects of lignin on soil's absorbability were studied through determinat-ing the isotherrnal absorption. The results showed that: (1 ) Lignin could decrease soil's capacity to absoth phosphate, and the absoroption isotherm went down Obvi-ously; (2) With the increasing original concentration, whether or not lignin was applied in the soil, the difference of absorption to phosphate was gradually in-creased and was obviously different in different soils; (3) When original concentra-tion was 80 mg/l, which is the highest concentration in this test, the decreasing rates of absorption capacity to phosphate are 10.04 per cent in red earth,9. 82 per cent in yellow eath and 31. 30 per cent in purple earth, respectively.