浙西丘陵区不同采样密度富硒土壤评价研究

Assessment of selenium-rich soils in the hilly areas,western Zhejiang Province with different sampling densities

为精准确定富硒水田图斑,以浙西典型丘陵富硒区常山县球川镇棋盘山为研究区,采用1∶1万土地质量地球化学评价规范(平均采样密度为25.6件/km^2)和无样图斑属性赋值法(平均采样密度为55.2件/km^2)分析图斑实测值,对比研究浙西丘陵区富硒土壤硒含量及富硒图斑评价结果。无样图斑赋值结果与实测值相对双差合格率为60.71%,富硒图斑判定结果一致率为63.64%。研究区1∶1万土地质量地球化学评价规范采样评价精度尚难达到富硒图斑精准要求,应适当加大采样密度,尤其是无样图斑周边无实测图斑时,应布置采样点予以控制。

To accurately determine the patches of selenium(Se)-rich paddy fields,this study carried out geochemical analysis on soils from the Qipanshan Se-rich area,Changshan County in western Zhejiang Province.Based on 1∶10000 Geochemical Evaluation Criterion of Land Quality(an ave.sampling density of 25.6 pieces/km^2)and average assigned values of non-sample patches at an average sampling desity of 55.2 piece/km^2,Se contents of Se-rich soils and evaluation results of Se-rich patches in the hilly areas were obtained.The results show that the qualified rate of two differences between non-sample pattern assignment and measured value is 60.71%,with the consistency rate of selenium-rich pattern determination up to 63.64%.The accuracy of sampling evalution of the 1∶10000 geochemical evalution for land quality in the study area is still difficult to meet the requirement of accurate determination of Se-rich patches.Therefore,sampling density should be increased appropriately,and deployment for sampling positions should be under control especially in no actual measured patches around non-sample patches.