山东主要土类有机质及其与供磷特性的关系

山东省3大土类中棕壤的有机质含量最高,平均为10.69g kg-1,其次为褐土和潮土;高产农田的有机质含量平均为10.9g kg-1,高于中低产田。相关分析结果表明,土壤的主要养分含量中有机质含量与土壤有效磷含量的密切正相关,进一步分析表明,土壤的有机质含量与土壤全磷、有机磷、有效磷、磷酸化酶活性和土壤微生物转化难溶性磷的强度均呈正相关,而与磷吸附最大缓冲容量MBC、固磷百分率、解吸能Qm呈负相关;逐步回归结果表明有机质对棕壤中的中度活性有机磷MLOP、潮土中的Ca2-P、褐土中的A l-P、高产农田中的A l-P,中低产田的Fe-P均显著的正相关;而且这种相关性均是高产农田大于中低产田。有机质不仅直接丰富了高产农田的磷库,而且通过提高磷酸化酶的活性,降低土壤磷的吸附、固定,促进解吸,增加了土壤磷的有效性。

Soil Organic Matter as Related to P Releasing Properties in Different Types of Soil in Shandong Province

The results of correlation analysis indicated that soil organic matter was positively correlated with soil total P,organic P,available P,phosphoratase activities and P trans for mation intensity,and the coefficient of soil organic matter with soil available P was the most significant.The results of correlation also indicated that organic matter significantly affected MLOP in brown earth,Ca2-P in fluvo-aquic soil,Al-P in cinnamon,Al-P in high yield soil and Fe-P in low yield soil,and this effect was more effective in the high yield soil than in the low yield soil.This is because that organic matter enriched not only phosphorous in the high yield soil,but also increased soil phosphorous availability through decreasing absorption and fixation.