三峡库区紫色土坡耕地氮磷径流特征研究

Character of Loss of Nitrogen and Phosphor on Slope Farmland of Purple Soil in Three Gorges Reservoir

在三峡库区主要土壤类型(紫色土)、坡度(5°、25°)、种植模式(柑桔-牧草)上建立径流池,旨在研究自然环境条件下土壤氮磷径流特点.结果表明径流水的总氮平均浓度在5°坡度时明显高于25°坡度,径流水的总氮和总磷浓度在25°坡度变化幅度大于5°坡度.坡度平缓时,径流水的总氮和总磷浓度明显呈正态分布.5°坡度氮径流量和磷径流率呈显著性正相关,25°坡度径流水的总氮量和总磷量呈显著性正相关.5°坡度径流水的总磷量与土壤全磷含量呈显著性负相关,曲线模拟成S形曲线.相同坡度条件下,径流水的总氮量、土壤氮径流量明显高于径流水的总磷量和土壤磷径流量,但土壤氮和磷的径流率接近.

The experiment was conducted in main soil type （purple soil）,and slopes（5°,25°）,and planting pattern （orange-weed）. The results showed that the average concentration of total nitrogen in runoff water was bigger at 5° slope than at 25° slope, and the variety scopes of total phosphor and total nitrogen in runoff water were wider at 25° slope than at 5° slope. When the slope was subdued,the concentration of total phosphor and total nitrogen belonged to normal dis- tribution. It was significant positive correlation between the amount of loss of nitrogen and run- off rate of phosphor in soil at 5° slope, and it was significant positive correlation between the a- mount of loss of total nitrogen and total phosphor in runoff water at 25° slope. It was signifi- cant negative correlation between the amount of total phosphor in runoff water and the contents of total phosphor in soil at 5° slope, and the curve simulation was s curve. The amount of total nitrogen was higher than the amount of total phosphor in runoff water, and the amount of loss of nitrogen was higher than the amount of loss of phosphor in soil in the same slope, but the runoff rates of phosphor and nitrogen in soil was near.