不同时期围海造田水稻土肥力剖面分布特征

Profile Distribution of Fertility Parameters of Foreshore Reclamation Paddy Soils

以浙江省慈溪市三个代表性时期(宋代,明代,近代)围海造田水稻田土壤为研究对象,每个时期采二个土壤剖面,室内分析土壤肥力参数(有机质、总氮、总磷、总钾、速效磷、速效钾、pH),研究不同时期围海造田土壤肥力剖面分布(0～100cm)特征及其水稻种植时间对土壤肥力的影响。结果表明,不同时期围海造田水稻田土壤剖面全钾含量均随剖面深度增加而增大;土壤全钾含量随着水稻种植时间的延长而增大。建议采用水稻与深根作物轮作,利用底土层土壤钾素。随着水稻土利用年限的增长,磷素在土壤表层富集加聚,因此,稻田磷输出对水体富营养化影响值得关注。

Two profiles （O-lOOcm） of the foreshore reclamation paddy soil at three typical periods （Song dynasty, Ming dynasty and Present age） were taken at Cixi City, Zhejiang Province, and soil fertility parameters （organic matter, total N, Total P, Total K, Olsen-P, available K and pH） were determined. The results indicated that soil total K contents increased with the increase of soil profile depth and longer duration of rice - planting. We suggest the rotation system between rice and deep root crops to explore soil K source in deeper layer to meet crops demand for K. The top layer soil P gradually enriched with the increase of duration of rice-planting. Therefore, surface water eutrophication resulting from rice fields P transport should be paid more attention.