东北地区中部主要农业土壤中若干金属元素的背景值

BACKGROUND VALUES OF CERTAIN METAL ELEMENTS IN MAIN AGRICULTURAL SOIL OF MIDDLE NORTHEASTERN IN CHINA

农业土壤是自然土壤开垦种植后,在自然因素和人为活动双重影响下长期形成的。所以农业土壤中各种元素的含量既与自然土壤有关联,而又与自然土壤有一些差异。采集东北地区中部近70个土壤剖面200个样品,用原子吸收法、阳极溶出伏安法和萤光光度法等分别测定了镉、铜、铁、汞、锰、镍、铅、锯、锌、硒等元素的含量。通动表土与心土对比法,4 d法和(?)+2s法剔除异常值,采取直方图法、概率纸法、Vistelius置信带法、Kolmogorov,Smirnov法和偏度、峰度法进行检验,综合判定元素概率分布类型。分别以表层土壤的(?)±S和M/D-M·D表示耕种暗棕壤、耕种黑土,耕种暗色草甸土和水稻土的元素背景值。 随着农业土壤腐殖质层的变薄和耕作层有机质含量的下降,许多元素的含量随之降低,尤以汞、锰、硒、锶为明显。

Agricultural soils are formed for long period under influence of both natural factors and human activities after reclamation and planting of natural soils,So the content of various elements in agricultutre both concerns natural soils and differ from natural soils.We collected over 200 samples in 70 soil profiles.Certain elements of Cd, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn were determined with atomic adsorption spectrophotometry, anodic stripping voltammetry and fluorescence spectrophotometry.Abnormal values were eliminated, through methods of comparing the surface and subsurface of soil, 4d and x + 2s The probability distribution type of elements was decided comprehensively using methods of histogram, proba bility paper, Vistelius, kolmogorov-smirnov, deviation and peak value.x±s and M/D-M-D indicate background values of elements of phough dark brown soil plough black soil, plough dark meadow soil and paddy soil respectively.The content of many elements, especialy Hg, Mn, Se and Sr,has reduced obviously with thinning of humic horizon in agricultural soil and decreasing of organic content in plough horizon