天津市农业耕地土壤养分演变状况的调查

耕地土壤养分调查数据表明,天津地区土壤有机质、全氮、全磷、全钾、速效氮、速效磷、速效钾总体呈逐年增加的趋势,土壤微量元素呈下降的趋势。2003年与1981年比较,土壤有机质、全氮、速效磷、速效钾分别增加26.39%,7.95%,404.26%,28.44%,而土壤有效铜、有效锰、有效锌分别降低了55.87%,21.25%,65.83%。土壤有效铜、有效锰已经低于或接近土壤临界值;土壤有效铁、锌、硼、钼等微量元素还较丰足。

Evolvement Status of Agro-plowland Soil Nutrients in Tianjin

Agrarian soil organic matter,total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus and available potassium submitted an ascending tendency in Tianjin and all their contents in soil were more than soil critical values.Soil available Cu,available Mn and available Zn in year 2003 decreased by 55.87%,21.25% and 65.83% compared with that of year 1981. Soil available Cu,available Mn had already been lower than or approached critical values,agrarian soils have already been short of Cu,Mn.Soil available micronutrients,such as Fe,Zn,B and Mo is still abundant.