江苏建湖县耕地质量现状及变化趋势分析

Analysis of the Current Status and Variation Trend of the Cultivated Land Quality in Jianhu County, Jiangsu Province

根据2016-2018年省、市耕地质量监测点监测数据,统计分析江苏省盐城市建湖县耕地质量现状,研究农田施肥后土壤养分的变化趋势。通过3年的耕地质量监测点养分监测,结果显示,施肥对农田土壤有机质、全氮、有效磷和速效钾含量的影响较为明显,施肥区养分的含量普遍高于无肥区;施肥区耕层土壤的有机质含量基本稳定,较多无肥区有机质的含量呈现缓慢下降趋势,相应无肥区全氮的含量也呈现一定的下降趋势;施肥区有效磷的含量相对稳定,无肥区则显示出一定的下降趋势;建湖县近几年来钾肥的使用量不足,施肥区的速效钾含量与无肥区均有一定的下降趋势,但施肥明显降低了速效钾的下降幅度。农田耕层土壤的养分状况是施肥技术、种植制度及土壤田间环境条件等综合作用的结果。3年来耕层土壤的pH值、有机质含量、碱解氮含量、有效磷含量、速效钾含量等变化基本上保持平稳。

Based on the monitored data of cultivated land quality from the provincial and prefectural monitoring sites during the period of 2016―2018,this study performed statistical analyses of the current status of the soil quality of cultivated land in Jianhu County,Jiangsu Province,and evaluated the variation trend of the contents of soil nutrients in the cultivated land with fertilization.As a result,fertilization produced significant effects on the contents of soil organic matter,total nitrogen,available phosphorus,and rapidly available potassium in cultivated land;the nutrient contents in fertilized soils were consistently higher than those in non-fertilized soils.Soil organic matter content in the tillable layer remained relatively stable in fertilized soils,but slowly decreased in non-fertilized soils in which total nitrogen content also showed a decreasing trend.Moreover,available phosphorus content was relatively stable in fertilized soils,but kept decreasing in non-fertilized soils.Owing to insufficient applications of potassium fertilizers in Jianhu County in recent years,the rapidly-available potassium content in soil showed a downward trend in both fertilized and non-fertilized farmlands;however,fertilization apparently reduced the declining trend of the rapidly-available potassium content in soil.The status of soil nutrients in the tillable layer of cultivated land results from the overall interactions among fertilization technologies,the cultivation system,and environmental conditions of field soils.During the three years,the soil quality in tillable layer remained stable in general with respect to its pH value and contents of organic matter,total nitrogen,available nitrogen,available phosphorus,and rapidly-available potassium.