上海市奉贤区农田土壤肥力现状及变化特征

Present situation and variation characteristics of soil fertility of farmland in Fengxian District of Shanghai

通过对上海市奉贤区2009—2018年定点土壤样品进行采集和分析,研究该区农田土壤肥力现状及理化性质变化特征。结果显示:上海市奉贤区土壤有机质、碱解氮、有效磷、速效钾的平均含量和pH分别为25.61 g∕kg、119.15 mg∕kg、50.84 mg∕kg、144.23 mg∕kg和6.59,分级标准为1—3级。土壤中有机质、有效磷、速效钾和pH的空间分布较均匀,而碱解氮的空间格局表现出明显差异。10年间,奉贤区土壤有机质含量逐年上升;碱解氮、有效磷和速效钾含量较充足,年际变化较大,但不同利用方式土壤的肥力表现上有差异,粮田要低于菜田和果园。建议奉贤区农田土壤应控制氮肥施用量,实施秸秆还田和增施有机肥等培肥措施,以使土壤养分供需平衡。

In order to analyze the present situation and variation of physical and chemical soil properties of farmlad in Fengxian District,Shanghai,soil samples collected from fixed points from 2009 to 2018 were analyzed.The results showed that the soil of average contents of organic matter,alkali-hydrolyzable nitrogen,available phosphate,rapidly available potassium and pH were 25.61 g∕kg,119.15 mg∕kg,50.84 mg∕kg,144.23 mg∕kg and 6.59,respectively,which were mainly distributed in the standard class 1—3.The spatial distribution of organic matter,available phosphate,rapidly available potassium and pH was uniform,and alkali-hydrolyzable nitrogen was obviously different.During the past 10 years in Fengxian District,the content of organic matter gradually increased year by year.The contents of alkali-hydrolyzable nitrogen,available phosphate,rapidly available potassium were sufficient,and their annual changes were relatively large.However,the fertility of soil with different usage styles showed a great difference,and the fertility in grainfield was lower than that of the vegetable field and orchard.It was suggested that the application amount of nitrogen fertilizer should be controlled,and the straw incorporation and organic fertilizer application should be strengthened to achieve the balance of supply and demand for soil nutrients.