不同类型黄壤旱地的磷素流失及其影响因素分析

Phosphorus Loss by Runoff in Various Dryland from Yellow Soil and Its Affecting Factors

在贵州中部黄壤旱地上 ,通过模拟降雨试验方法 ,对不同类型黄壤旱地磷素流失及其影响的主要因素进行研究。结果表明 ,黄壤旱地磷素流失以颗粒态形式流失为主 ,其占地表径流总磷含量的 86 .4%～ 99.9% ;不同类型黄壤旱地随地表径流流失的颗粒态磷 (泥沙结合态磷 )量和磷酸根态磷 (水溶态磷 )量存在较大差异 ,高肥力旱地磷的流失量明显高于低肥力旱地。影响黄壤旱地颗粒态磷和磷酸根态磷流失量的首要土壤因子都是有效磷含量 ;在土壤磷素水平一致下 ,黄壤旱地颗粒态磷流失量与 <0 .0 0 1mm粘粒含量呈显著正相关 ,而磷酸根态磷流失量与土壤交换性钾含量呈显著负相关。此外 ,降雨强度对旱地磷素流失产生明显影响 ,高降雨强度将加速颗粒态磷的流失 ,从而明显地提高旱地磷素流失量 ;

Phosphorus loss by runoff and its affect factors were studied in various upland fields form yellow soil of Guizhou province.The results showed that with a rainfall simulation experiment particulate P and ortho P losses with surface runoff in various upland fields were different, which the phosphorus losses in the upland field with high fertility were obvious. The important factors affecting particulate P loss were the contents of available P and <0.001mm clay of the soil. The other, the main factor affecting ortho P loss was the soil available P content. In addition, higher rainfall intensity increased particulate P loss so as seriously to enhance the soil P loss, while lower rainfall intensity increased ortho P loss.