模拟酸雨、磷肥对红壤铁氧化物及速效磷的影响

Effect of Simulated Acid Rain and Phosphorus Fertilizer on Iron Oxides and Available Phosphorus of Upland red Soil

为阐明酸雨、磷肥对铁氧化物和速效磷的影响,进一步揭示铁氧化物和磷的交互作用。以种植蔬菜5年,抛荒2年的旱地红壤为研究对象,研究了施磷肥后经不同强度和持续时间的模拟酸雨浸泡、速效磷、游离铁氧化物、无定形铁氧化物对模拟酸雨、磷肥的响应。结果表明:速效磷随施磷量、酸化天数的增加而增加,磷肥对速效磷的影响大于酸对速效磷的影响;磷肥对游离铁氧化物、无定形铁氧化物的影响不显著,不同强度酸作用下,土壤游离铁氧化物表现为:9 d>3 d>15 d>6 d,无定形铁氧化物表现为:6 d>15 d>9 d>3 d;酸化作用下游离铁氧化物与无定形铁氧化物存在此消彼长的关系,铁氧化物形态的转化影响磷的释放,无定形铁氧化物的释放促使了磷的释放。

In order to clarify the effect of acid rain and P fertilizer on iron oxide and P availability, and further disclose the interaction between iron oxide and P in the soil. The experiment was carried out using upland red soil. The soil which had grown vegetables for 5 years and been barren for 2 years was selected. Results shown available phosphorus increased with the increasing of phosphorus application and acidification days. Phosphorus application had a stronger influence on available phosphorus than acidification days. Phosphorus fertilizer had no significant effect on crystal iron oxide and amorphous iron oxide, and its influence was less than that of simulated acid rain solutions. After acidifica tion, the amount of crystal iron oxide in the soil was 9 d〉3 d〉15 d〉6 d,and amorphous iron oxide was 6 d〉15 d） 9 d〉3 d. Two iron oxides had the relationship of this disappearing and that rising. The transformation of two iron oxides affected P availability. The release of amorphous iron oxide improved the release of available phosphorus.