苏州城市边缘带土壤综合肥力质量时空特征

对苏州市城市边缘带样区土壤进行系统的采样分析,应用一系列数理统计分析方法,阐述了研究区土壤主要肥力要素的空间变异特征及其影响因素;利用数值化土壤综合肥力评价手段,估算了研究区土壤数值化肥力质量指数及其空间分异规律;并通过与研究区历史数据对比,揭示了过去20年来苏州市城市边缘带土壤主要肥力要素及综合肥力质量的动态演变趋势。结果表明,研究区表层土壤电导率、CEC以及养分含量空间变异强烈,表现出城市边缘带土壤肥力分布的重要空间特征。经过过去20年的农业生产实践,研究区土壤主要养分含量总体上呈现增长趋势,土壤综合肥力质量明显提高。但土壤全K含量却呈下降趋势,表明土壤养分不均衡现象依然存在。土壤pH大幅下降,土壤酸化现象严重。选取的10个样本土属中,平均综合肥力质量指数增高和降低的土壤数量分别为5个和4个。同时,土壤综合肥力质量空间可变性显著增大,最大变幅与变异系数明显升高,反映出快速工业化、城市化与农业集约化背景下土壤资源利用方式与利用强度的变化对土壤质量结构及其空间变异特征的重要影响。

Spatial -temporal Variation of Integrated Soil Fertility Quality Index in the Peri -urban Suzhou

Based on the data obtained from soil investigation and laboratory analysis,the integrated fertility quality index of the sampled soils from the peri-urban area of Suzhou was calculated by employing the methodology of numerical evaluation of soil fertility.And,using Kriging interpolation the distribution pattern of integrated soil fertility quality was predicted and its spatial variation and driving factors were analyzed.Furthermore,dynamic change of soil fertility quality of different soil type during the last 20 years was demonstrated,by comparing the related results derived from newly available and historical data setsre spectively.The results showed that the integrated soil fertility of the studied area varied significantly,reflecting the influence of diversified land utilization and management on soil quality of the peri-urban region.Taking the studied area as a whole,the soils commonly had a higher integrated fertility quality index in the eastern part than their counterpart in the western part.In general,during the last 20 years soil fertility quality had been significantly improved and the average index of integrated fertility quality in the studied area had increased by some 10%.And the integrated fertility quality index of the five out of the ten soil genera chosen for the study increased,while 4 soil genera decreased.Meanwhile,it was revealed that spatial variability of soil fertility quality also significantly increased in the studied area.This might be caused by strong changes in land use and management induced by rapid industrialization,urbanization and development of intensive agriculture.