浙江省稻田土壤养分现状及演变趋势

Current status and evolution trends of soil nutrients in the paddy soils in Zhejiang Province

通过对2009年浙江省260个水稻土养分含量的分析,并结合第二次土壤普查时期土壤养分资料,探讨浙江省稻田土壤养分的变化规律。结果表明,经过连续25年种植,浙江稻田土壤pH明显下降,稻田在pH值5.51～6.50所占的比例由1984年的59.3%下降到2009年的22.3%。有机质同期降低了13.9%。土壤全氮整体水平较高,变化不明显。有效磷含量大幅上升,比1984年提高了158.3%,尤其是〉20.0 mg·kg^-1的稻田所占的比例由1984年的5.3%上升到2009年的25.0%,约为25年前的5倍,但同期速效钾含量却降低了34.8%,稻田土壤缺钾现象十分普遍。

The nutrient changes of 260 paddy soils sampled from Zhejiang province in 2009 were studied based on the soil nutrient data obtained from the Second National Soil Survey. The results showed that the value of soil pH decreased obviously after 25 years of continuous cropping. The ratio of paddy field at pH value of 5. 51 to 6. 50decreased from 59. 3% in 1984 to 22. 3% in 2009. Moreover,the mean value of soil organic matter was decreased by 13. 9%. However,the level of soil total nitrogen was higher. The content of available-P markedly increased,especially the ratio of paddy field with available-P content 20. 0 mg· kg^-1 increased from 5. 3% in 1984 to25. 0% in 2009. The mean value of available-K was decreased by 34. 8%. The K-deficiency of paddy fields is still very common in Zhejiang province.