海涂围垦区土壤质量综合评价的指标体系研究

以苏北海涂围垦区为研究区域,选取与作物生长密切相关的理化性质为指标,采用模糊数学方法对土壤质量状况进行了定量评价,获取了区域土壤质量状况分布图,并对不同指标体系下的评价结果进行了比较分析.结果表明:研究区土壤质量状况总体较差,有机质是重要的土壤质量评价因子,土壤盐分与地下水矿化度是土壤质量的主要限制因子；不同评价方案获得的土壤质量状况具有空间相似性,西部棉花种植区土壤质量状况总体优于东部的水稻种植区；体积质量对土壤质量评价差异影响较小,速效养分对土壤质量评价影响较大,基于速效养分的土壤质量评价精度高于全量养分；在其他因素获取困难的情况下,采用土壤有机质、速效养分和盐分或仅采用土壤有机质和盐分作为评价指标亦能较好地反映土壤质量状况.该研究可为海涂围垦区土壤质量快速评价指标体系的构建、中低产地的科学改良和管理提供一定理论依据.

Study on Synthetic Evaluation Index Systems of Soil Quality in Coastal Reclamation Region

Some soil physico-chemical properties relevant with crop growth were selected as the evaluation indices and then soil quality in typical coastal reclamation region in north Jiangsu Province was quantitatively assessed by using fuzzy mathematics. Synthetic evaluation maps of soil quality status were generated and the results of different evaluation index systems were further compared. Results indicated that soil quality across the study area was generally poor. Soil organic matter (SOM) was the most important evaluation factor of soil quality, while soil salinity and groundwater mineralization were the limiting factors of soil quality. Classification maps of soil quality evaluated by different schemes were quite similar in spatial patterns, and soil quality in cotton-growing field was superior to that in rice-growing field generally. Bulk density had an insignificant influence on evaluation results, which was contrary for available nutrients. The evaluation accuracy based on available nutrients was better than that based on total nutrients. Evaluation index systems including SOM, available nutrients and salinity or merely SOM and salinity could be used to evaluation soil quality when evaluation data were limited. The results can serve as a theoretical reference for the establishment of practical evaluation index systems, scientific amelioration and management of moderate-and-low-yield farmlands in coastal reclamation region.