苏北海涂围垦区耕层土壤养分分级及其模糊综合评价

Classification and fuzzy synthetic evaluation of soil nutrient at plough horizon in coastal region of north Jiangsu province

针对制约滩涂土壤资源开发利用的障碍因素,以苏北滨海滩涂围垦区为研究区域,应用模糊综合评价方法对耕层土壤养分进行了分级与定量评价,获取了区域土壤肥力状况分布。结果表明,研究区域土壤磷素和钾素相对富余,有机质和氮素含量偏低,氮素亏缺较为严重,尤其是碱解氮。模糊综合评价表明研究区土壤养分分布在Ⅰ、Ⅱ、Ⅲ级,主要集中在Ⅰ、Ⅱ级,并没有Ⅳ级和Ⅴ级土壤;尽管总体上处于Ⅱ级水平,但可认为其养分仍处于极贫乏状态。研究区不同部位土壤养分分级存在明显差异性,养分分级较低的部位作物生长状况较差,土壤盐渍化程度较高。研究结果为海涂围垦区中、低产地土壤培肥和农田精确施肥提供一定的参考依据。

Aiming at soil obstacles restraining the exploitation and utilization of coastal soil resources, classification and quantitative assessment of soil nutrient at plough horizon was performed by using fuzzy synthetic evaluation method, which was conducted in coastal region of north Jiangsu province. The distribution of regional soil nutrient status was further obtained. The results indicated that available P and K was relatively abundant, the content of organic matter （OM） and N nutrient was relatively low, and N nutrient was in severe deficiency, especially alkali dispelled nitrogen. Fuzzy synthetic evaluation results showed soil nutrient status across the study area was classified into rank Ⅰ , Ⅱ and Ⅲ, and mainly into rank Ⅰ and Ⅱ. There existed no soil samples of rank Ⅳ and Ⅴ. Soil nutrient status across the study area was actually in extreme deficiency, although it was classified into rank Ⅱ generally. Soil nutrient classifications differed significantly at different positions of the study area. The crop growth was in poor status and soil was highly salinized at positions of low nutrient classification. The research results could serve as a theoretical reference to the soil fertility improvement and precision fertilization of moderate and low-yield farmlands in coastal region.