有机酸对不同磷源施入土壤后速效磷变化的影响

采用室内无菌培养方法,模拟缺磷胁迫条件下植物根系分泌的有机酸种类和数量,研究草酸、 柠檬酸、苹果酸、酒石酸、腐殖酸5种有机酸对不同磷源施入土壤后速效磷动态变化的影响。结果表 明:不同磷源施入土壤后都会使土壤中速效磷含量增加,而后随时间的推移,速效磷含量迅速下降, 大约30-45d后趋于稳定;供试有机酸均能增加土壤速效磷含量,能明显减弱速效磷含量随时间而降 低的趋势,使得土壤速效磷含量在较长的一段时间内保持较高的水平;有机酸对石灰性潮土速效磷 动态变化影响能力因有机酸种类和性质的不同而不同,其作用能力大小顺序为:草酸、腐殖酸>柠檬 酸、苹果酸>酒石酸。

Effect of Organic Acids on Dynamic of Rapidly available Phosphorus Enter Different Phosphorus to Soil

By incubating under the abacterial condition, simulating the types and the concentrations of organic acids that plant roots excreted under phosphorus stress, the effect of organic acids on dynamic of rapidly available phosphorus enter synthetic phosphorus to calcareous alluvial soil been studied. The main contents were: (1) The available phosphorus content quickly increased by application of different synthetic phosphate, and then quickly decreased by time, and were steady after 30-45 day; The organic acids inhibited the trend of available phosphorus decreasing by time, so available phosphorus kept a high level in a long time in soil; The inhibiting ability of organic acids followed the order: oxalic acid, humic acid > citric acid, malic acid > tartaric acid.