酸雨对紫色土氮磷淋失的影响

利用土柱淋洗模拟试验,研究了酸雨影响下,不同施肥处理紫色土氮、磷淋失的动态变化特征。结果表明,在酸雨作用下,紫色土中硝态氮的淋失量远远大于磷元素;不同施肥处理下二者淋失量的大小不同,淋失量大小排序均为有机无机混合施用〉化肥〉有机肥〉对照处理;淋失量受施肥量和降雨量的影响明显,土壤中硝态氮、磷元素淋失量随施肥量的增加而增加,淋失过程主要集中在雨季。同一施肥处理下,土壤硝态氮淋失量随降雨pH值的升高而增加;pH值5.5是土壤磷元素淋失量的临界点,此时土壤有效磷含量最高,淋失量达到峰值。

Effect of Acid Rain on Leaching Loss of Nitrogen and Phosphorus

Using the soil columns leaching experiment,the dynamic change characteristics of leaching loss of nitrate nitrogen and phosphorus in the Purpli-Udic Cambosols soil affected by acid rain with different fertilizers were investigated.The results showed that the leaching loss of nitrate nitrogen in the soil was far more than that of phosphorous.The leaching loss of both was obviously influenced by the amount of fertilizers and acid rain and can be shown in the order of Organic manure>Fertilizer>Organic manure>Control check treatment.The loss of nitrate nitrogen and phosphorus increased with the amount of fertilizers increasing and mainly occurred in the rainy season.Under the same kind of fertilizer,the loss of nitrate nitrogen increased as the pH values of rain rose.However,the 5.5 of pH value was a critical point for the loss of phosphorus when there was the largest amount of available phosphorus in the soil and the loss came to the head.