长期地膜覆盖与施肥条件下土壤中磷素的变化

采用对比法对沈阳农业大学长期(1987～2005)地膜覆盖定位试验地棕壤中磷素的变化情况进行了研究。结果表明,经过19年的长期耕作,施有机肥或磷肥均能显著增加土壤中全磷、有机磷和速效磷的含量,但都不如有机无机肥配施;覆膜后除N4P2处理外,其余处理土壤全磷含量均大于裸地,覆膜后有机磷含量与裸地相比变化不大。地膜覆盖明显减少了速效磷的含量,增加了磷的移出量。同时表明增施有机肥是恢复和提高覆膜后土壤磷素肥力的较好措施。

Changes of Phosphorus in Soil under Conditions of Long-term Mulching with Plastic Film and Fertilization

The long-term located field experiment in Shenyang Agricultural University in 1987~2005 showed that through long-term cultivation for 19 years,application of organic P manure or P fertilizer could obviously increase the contents of total P,organic P and available P in soil,but their effects weren't better than the effects from the combination treatment of organic manure and inorganic fertilizer.The total P content in soil covered with plastic film was higher than that in nakedness soil in all the treatments except N4P2 treatment.And the organic P content in soil covered with plastic film changed little compared with that in nakedness soil.The mulching with plastic film could remarkably reduce the available P content and increase the P transferring amount.It was also found that the application of organic matter was a suitable measure to recover and enhance the P fertility in soils mulching with plastic film.