河南省砂姜黑土基本性质时空变化分析及重金属风险评价

发布时间：2018-05-31 02:23

本文选题：河南 + 砂姜黑土　；参考：《郑州大学》2015年硕士论文

【摘要】：土壤资源是人类赖以生存的最基本和最重要的自然资源,土壤的基本性质是评价土壤肥力的重要指标,影响作物生产水平,而重金属风险等级关系着土壤环境质量安全。本文在室外采集与室内分析测定的基础上,对河南省砂姜黑土基本性质的时空变化及其重金属风险评价进行研究,对河南省土壤资源及农业可持续发展具有重要意义。研究结论如下：(1)研究区砂姜黑土表层质地以粉砂壤土为主,表层pH平均值由7.8下降至6.9,变异系数最小,为14.2%；有机质平均含量由12.60 g/kg上升至13.11g/kg; CEC的平均值为21.96 cmol/kg,相比1979年下降了1.13 cmol/kg,降低了4.9%,下降幅度相比较小,变异系数为39.8%；有效磷平均值由1979年的4.8 mg/kg上升到2012年的33.6 mg/kg,变异系数最高,为71.2%；全氮含量2012年平均值为1.20 g/kg,较1979年含量升高；速效钾含量由139.1 mg/kg上升至190.4 mg/kg,增加了51.3 mg/kg,变异系数为44.8%。产生这些变化的原因基本归结为自然因素和人为因素,人为因素主要包括土地管理方式的改变、秸秆还田、肥料施用等。(2)砂姜黑土不同地区表层土壤pH值与全氮含量相近；表层土壤CEC含量除周口外,驻马店、许昌、南阳基本一致；有机质含量变化差异较大,从8.9g/kg到24.3g/kg不等；有效磷、速效钾含量最大值分别是许昌的42.7 mg/kg,南阳的255.3 mg/kg,最小值分别为周口的15.4 mg/kg和驻马店的141.7 mg/kg。(3)不同地区砂姜黑土pH值随剖面的下降基本保持不变；土壤CEC和速效钾含量在不同地区剖面层次变化趋势不同；有机质、有效磷含量在剖面由上到下不断下降,而全氮含量总体保持缓慢下降的趋势。(4)研究区砂姜黑土单因子污染指数评价法中土壤Hg、As含量超标率分别为50%、18.2%,Cd、Cr、Cu、Ni, Pb、Zn均达标,重金属污染等级排序为Pb(0.070)Cu(0.130) Cr(0.328) Zn(0.392) Cd(0.401) Ni(0.520) As(0.806) Hg(1.743);内梅罗综合污染指数法中P综合最大值为5.273,最小值为0.438,平均值为1.506; Hakanson潜在生态风险评价法中一个样本属于强风险等级,四个样本属于中等风险等级,其余均属于轻微风险等级,且其单因子潜在生态危害系数Eir为Pb(0.350)Zn(0.392)Cu(0.650)Cr (0.656) Ni(2.601As(8.059)Cd(12.018)Hg(69.707);以上三种方法均以国家土壤环境标准二级标准值为参考值,而地积累指数评价法以国家土壤背景值为参考值,对8种重金属污染程度排序为Pb(-0.97) Ni(-0.75) Cu(-0.62)= Cr (-0.62) Zn(-0.25) Cd(0.04) As(0.21) Hg(1.99),90.9%的样本均受到Hg污染,大部分污染等级属于中度～强污染等级；其次是As污染严重,50%属于轻度～中度污染,10%以上属于中度～强污染；Cd有59.1%的样本属于轻度～中度污染,Pb未污染,其余元素的轻度～中度污染频率在20%以下。由单因子污染指数法评价法、内梅罗污染指数法、Hakanson潜在生态风险评价法和地积累指数评价法综合研究可知,该研究区砂姜黑土重金属为轻微风险等级。
[Abstract]:Soil resources are the most basic and important natural resources for human survival. The basic properties of soil are an important index to evaluate soil fertility and affect crop production level, while heavy metal risk levels are related to the quality and safety of soil environment. On the basis of outdoor collection and indoor analysis, this paper studies the temporal and spatial changes of the basic properties of Shajiang black soil in Henan Province and the risk assessment of heavy metals, which is of great significance to the sustainable development of soil resources and agriculture in Henan Province. The results are as follows: (1) the surface texture of Shajiang black soil in the study area is mainly silty loam, the average pH value of the surface layer decreases from 7.8 to 6.9, and the coefficient of variation is the least. The average content of organic matter increased from 12.60 g/kg to 13.11 g / kg; the average value of CEC was 21.96 cmol / kg, which was 1.13 cmol / kg lower than in 1979, and 4.9% lower than that of 1979. The mean value of available phosphorus increased from 4.8 mg/kg in 1979 to 33.6 mg / kg in 2012, and the coefficient of variation was the highest (71.2%), the average of total nitrogen content in 2012 was 1.20 g / kg, which was higher than that in 1979. The available potassium content increased from 139.1 mg/kg to 190.4 mg / kg, increased by 51.3 mg / kg, and the coefficient of variation was 44.8 mg / kg. The main reasons for these changes were natural and human factors, such as the change of land management, the return of straw to the field, the application of fertilizer, etc.) the pH value of topsoil in different areas of Shajiang black soil was similar to the content of total nitrogen. Except for Zhoukou, Zhumadian, Xuchang and Nanyang, the content of CEC in surface soil is basically the same; the content of organic matter varies greatly, ranging from 8.9g/kg to 24.3g/kg; available phosphorus, The maximum value of available potassium was 42.7 mg / kg of Xuchang, 255.3 mg / kg of Nanyang, the minimum of 15.4 mg/kg of Zhoukou and 141.7 mg / kg of Zhumadian. The content of CEC and available potassium in soil varied in different regions, and the contents of organic matter and available phosphorus decreased continuously from top to bottom in the profile. But the total nitrogen content kept the trend of decreasing slowly. 4) in the single factor pollution index evaluation method of Shajiang black soil, the soil Hgna-as content exceeded the standard rate of 50% ~ 18.2cm ~ (-1) CD ~ (2 +) Cr ~ (2 +) Cu ~ (2 +) Ni and Pb ~ (2 +) Zn were up to standard, respectively, in the shajiang black soil of the study area. The rank of heavy metal pollution is PBG 0.070 CuLi 0.130) CrP0. 328) ZnU 0.392) CDU 0.401) Nijiu 0. 801) Hgn 1. 806) Hgn 1. 743), the maximum value of P is 5. 273, the minimum value is 0. 438, and the average value is 1. 506. One sample in Hakanson potential ecological risk assessment method belongs to the strong risk grade, and the average value is 1. 506, and the maximum value of P is 5. 273, the minimum value is 0. 438, and the average value is 1. 506. The four samples belong to moderate risk grade, the others belong to minor risk grade, and their single factor potential ecological hazard coefficient (Eir) is Pb(0.350)Zn(0.392)Cu(0.650)Cr 0.656. However, the soil accumulation index evaluation method took the national soil background value as the reference value, and ranked the pollution degree of 8 heavy metals as follows: Pb-0.97) Ni-0.75) Cu-0.62U = Cr-0.62) Zn-0.25) CDO 0.04) As0.21) the samples were all polluted by Hg, and most of the samples were polluted by Hg, most of which belonged to moderate to strong pollution grade. Secondly, 50% of as pollution belongs to mild to moderate pollution and more than 10% belongs to moderate to strong pollution. 59.1% of the samples belong to mild to moderate pollution and Pb is not polluted, and the frequency of light to moderate pollution of other elements is less than 20%. According to the comprehensive study of single factor pollution index method, Nemero pollution index method and Hakanson potential ecological risk assessment method and land accumulation index evaluation method, it can be concluded that the heavy metals in Shajiang black soil in this study area are of slight risk grade.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S151.9;X825

【参考文献】