基于模糊数学法的滩涂围垦区土壤肥力特征评价

Application: Fuzzy Mathematics in Integrated Evaluation for Soil Fertility of Coastal Reclamation District

以慈溪市滩涂围垦区为例,通过对土壤配对样本有机质、全氮、速效磷、速效钾、电导率、pH值等土壤肥力评价指标的分析,运用模糊数学法从时间和空间两个维度对滩涂围垦区30年间的土壤肥力特征进行了综合评价.结果表明:慈溪市滩涂围垦区土壤综合肥力较30年前有所下降,土壤肥力综合指数值由1982年的0.5816下降到2012年的0.5151;其中有机质、电导率、全氮土壤肥力单项评价指标隶属度得分值下降较多;土壤综合肥力的空间变化为从南到北,土壤肥力呈阶梯状下降,由南到北土壤肥力的综合指数为:0.5413、0.5157、0.5522、0.5059.评价指标中,影响慈溪市滩涂围垦区土壤肥力程度由大到小分别为速效磷、电导率、有机质、全氮、pH和速效钾.

Taking the coastal reclamation district in Cixi city as the case study,we analyze the indices of the soil fertility including six physicochemical properties： organic matter,total nitrogen,valid phosphorus,valid potassium,conductivity and pH value.Using the fuzzy mathematic method,the characteristics of soil fertility are evaluated in the coastal reclamation district over the past three decades from perspective of the temporal and spatial variability.The results suggest that the soil fertility of the coastal reclamation district has been on the decline comparing with that measured three decades ago,and the integrated fertility index has decreased from 0.5816 in 1982 to 0.5151 in 2012.The membership degree of the single index evaluation including organic matter,conductivity and total nitrogen has decreased to a lower level than that of other indices.As for the spatial variation of soil fertility,it decreases gradually from north to south,and the integrated fertility index was found to be 0.5413,0.5157,0.5522 and 0.5059 respectively.The main factors impacting the soil fertility are in order of valid phosphorus〉conductivity〉organic matter〉total nitrogen〉pH value〉valid potassium.