山东省典型褐土的磷素淋溶特征及风险评价

为阐明褐土磷素在山东降雨条件下对水体富营养化的风险及其淋溶特点，采取了室内连续淋洗和模拟降雨淋洗的方法对山东省典型褐土的磷素淋溶特征进行了研究。结果表明，水溶性磷的淋失量随供磷水平的提高而增加；不同施磷量处理的淋洗峰值出现时间存在着明显差异，P7、P6及其它施磷处理的淋洗最大峰值分别出现在第3、4、5天；土壤速效磷(Olsen-P)、水溶性磷淋失量以及施磷量之间存在着明显的正相关关系；褐土中的速效磷能够随水发生垂直迁移，一年的降雨强度能使其向下迁移15cm左右；速效磷可以作为施磷量的一个重要指示指标。对于大多数农作物生产来说，在较低的施磷水平下（180kg/hm2以下），土壤速效磷含量均保持在20μg/g左右，既能满足作物高产的需要，又不会对水体产生危害。总之，控制施磷水平在180kg/hm2以下，可以做到高产与环境兼顾。

Phosphorus Leaching Character of Cinnamon Soil of Shandong Province and Its Risk Evaluation

To clarify the risk of water eutrophication caused by phosphorus of cinnamon soil and phosphorus leaching character under the condition of rainfall in Shandong Province, the methods of continuous leaching and simulated rainwater were used to study P leaching character of cinnamon soil in Shandong Province. Results showed that the amount of water soluble P leaching increased with the increase of P levels; There was obvious difference of P leaching peaks among the different P treatments, leaching peaks of P7, P6 and other P treatments appeared respectively at 3d, 4d and 5d; There were significant positive correlations between Olsen-P and water soluble P or and and P leaching amounts; Olsen-P of cinnamon soil could migrate vertically with water and was migrated down soil profile about 15cm by annual rainwater; Olsen-P was thought as an important indication for P application. It was thought that Olsen-P contents of soils were kept about 20μg/g under the lower P supplies (<180kg/hm2), and this could meet the demand for high yield of crops for most crops production and did no harm to water substance. In conclusion, if the amount of P application is controlled less than 180kg/hm2, both of crop high-yield and good environment can be achieved.