低分子有机酸对林地土壤磷释放及活化影响

为了解林地土壤中闭蓄态磷转化为有效磷的转化效率,以淮河流域固始县意杨林灰潮土为例,开展了在不同低分子有机酸、酸浓度及反应时间下灰潮土壤总磷(Total Phosphorus, TP)的释放及各形态磷,包括TP、无机磷(IP)、有机磷(OP)、Fe/Al-P和Ca-P的活化影响实验。实验结果显示,苹果酸、柠檬酸及草酸对土壤TP释放率分别增长了180%、161%和217%。苹果酸和柠檬酸对土壤TP的平均活化率均在164%以上,而草酸则在中浓度时才表现出活化作用。3种低分子有机酸均能有效促进灰潮土磷的释放与活化,且释放作用和有机酸种类、浓度及实验处理时间密切相关,活化作用也与酸种类和酸浓度相关性显著,研究结果为磷肥的合理施用和土壤有效磷的提升提供科学依据。

Effects of Low-Molecular Organic Acids on Soil Phosphorus Release and Activation in Woodland

In order to understand the conversion efficiency of closed storage phosphorus to available phosphorus in woodland soils, taked the populus euramevicana forest grey fluvo-aquic soils in Gushi County of the Huaihe River Basin as an example, the release of total phosphorus (TP) in grey fluvo-aquic soils and various forms of phosphorus, including TP, inorganic phosphorus (IP), organic phosphorus (OP), Fe/Al-P and Ca-P, were carried out at different low molecular organic acid, acid concentration and reaction time. The results show that the TP release rate of malic acid, citric acid and oxalic acid increased by 180%, 161% and 217%, respectively. The average activation rate of TP in soil by malic acid and citric acid is over 164%, while oxalic acid showed activation effect only at medium concentration. All of the three low molecular weight organic acids can effectively promote the release and activation of phosphorus in grey fluvo-aquic soils, and the release is closely related to the type and concentration of organic acids and the experimental treatment time, and the activation is also significantly related to the type and concentration of acids. The results of this study can provide scientific basis for the rational application of p fertilizer and the improvement of soil available P.