济宁南部区域耕作层土壤地球化学特征及其成因分析

济宁市南部区域是著名的国家商品粮、优质大蒜、优质稻米和有机蔬菜生产基地,由于土壤地球化学特征与农业生产、人类健康关系密切,所以对济宁南部区域耕作层土壤地球化学特征及其成因的研究具有十分重要的意义。本文以济宁南部煤田地区作为典型区域,以耕作层土壤为研究对象,采集了77件耕作层土壤样品,定量分析了As、B、Cd、Co、Cr、Cu、F、Hg、Li、Mn、Mo、Ni、Pb、Sr、Se、Zn、S、Corg、p H、Si O2、TFe2O3、Mg O、Ca O、Na2O、K2O、CEC等共计26项指标。经统计分析发现,济宁南部区域耕作层土壤中地球化学指标含量变异系数的大小顺序为HgCECSCdNa2OMoCa OCorgAsMnCuMg OCoLiNiTFe2O3SeZnFCrPbBSi O2SrK2Op H,其中Hg、CEC和S的变异系数较大,均超过了50%,这一特点与地球化学指标含量频率直方图及平均值与背景值的比对柱状图所显示的特征完全吻合。在摸清耕作层土壤地球化学特征的基础上,采用R型因子分析法对济宁南部区域耕作层土壤地球化学特征的成因进行了详细分析,提取了风化作用和淋溶作用复合因素、蒸发淀积作用和粘土物理化学吸附作用复合因素、植物根际富集因素作用、煤矿生产因素作用等四个因子,其方差贡献率分别为55.022%、12.753%、9.803%、8.009%,四个因子可以用于说明济宁南部区域表层土壤地球化学特征85.587%的形成原因。研究结果可以为研究区今后开展耕作层土壤环境质量评价,以及生态平衡研究奠定基础。

Geochemical Characteristics of Plowing Layer Soil in South Jining Region, Shandong Province, China and Its Contribution Factors

Southern district of Jining Region, Shandong Province, China is one famous production base for commodity grain, high quality garlic, rice and organic vegetables. It''s of great significance to investigate the relations of geochemical characteristics of soil with agricultural production and human health. Herein, 77 plowing layer soil samples were collected in southern Jining coal filed, and 26 indexes of the samples were detected including As, B, Cd, Co, Cr, Cu, F, Hg, Li, Mn, Mo, Ni, Pb, Sr, Se, Zn, S, Corg, pH, SiO₂, TFe₂O₃, MgO, CaO, Na₂O, K₂O, and CEC. According to statistic result, variable coefficients of geochemical index in southern Jining plowing layer soil were in the order of Hg > CEC > S > Cd > Na₂O > Mo > CaO > Corg > As > Mn > Cu > MgO > Co > Li > Ni > TFe₂O₃ > Se > Zn > F > Cr > Pb > B > SiO₂ > Sr > K₂O > pH. Results show that variable coefficients of Hg, CEC and S were all higher than 50% which was completely consistent with the frequency histogram and the comparison histogram of average and background value. On the basis of the results above, cause of plowing layer soil in southern Jining Region was meticulously analyzed with R factor analysis method. Four factors including combining factor of weathering and eluviation, combining factor of evaporation deposition and physicochemical adsorption of clay, plant rhizosphere accumulation factor and coal mining production factor were collected, and their contributions to the variance were 55.022%, 12.753%, 9.803% and 8.009%, respectively. These factors could be used to illustrate 85,578% of the cause of plowing layer soil in southern Jining Region. The result could lay the foundation for further soil environmental quality assessment and research on ecological balance.