本文選題：放射性核素 + 營養(yǎng)元素��； 參考：《南京師范大學》2015年碩士論文

【摘要】：南方紅壤丘陵區(qū)地處亞熱帶,高強度降雨的侵蝕、淋溶以及劇烈的生物循環(huán)等對當?shù)赝寥蕾|(zhì)量影響顯著,出現(xiàn)土壤質(zhì)量退化現(xiàn)象。土壤質(zhì)量退化導致土壤肥力逐漸下降、土壤結(jié)構(gòu)發(fā)生改變。在由侵蝕引起的土壤肥力降低過程中,土壤有機質(zhì)、土壤顆粒組成等變化明顯。因此了解土壤肥力狀況對于土地合理規(guī)劃、有效管理及農(nóng)業(yè)的可持續(xù)發(fā)展具有重要意義。鑒于放射性核素與土壤有機膠體、土壤顆粒等之間有較強吸附作用,探討放射性核素與土壤肥力因子間相互關(guān)系,對定性評價土壤質(zhì)量狀況有重要理論意義。本文選取江西省余江縣茶源山附近小流域作為研究對象,通過實地調(diào)查、樣品理化分析及放射性核素測定等方法,對土壤放射性核素137Cs、210Pbex與土壤各項理化指標(TOC、TN、TP、土壤團聚體、土壤粒度)之間進行相關(guān)關(guān)系分析,得出以下結(jié)果：(1)土地利用類型對土壤剖面中137Cs和210pbex的含量分布規(guī)律和變化特點有顯著影響,且兩種放射性核素在土壤中的運移規(guī)律十分相似。主要表現(xiàn)為：非耕地中137Cs、210Pbex的含量在0-20cm深度范圍內(nèi),隨土壤深度增加呈現(xiàn)指數(shù)衰減分布趨勢；農(nóng)耕地中137Cs、210Pbex的含量在0～20cm深度范圍內(nèi),隨土壤深度的增加呈相對均一分布趨勢。這說明137Cs和210pbex在土壤中的分布特征與運移規(guī)律具有明顯相似性。(2)不同土地利用類型下營養(yǎng)元素分布及其與土壤放射性核素之間相關(guān)關(guān)系差異顯著。主要表現(xiàn)為：①在不同土地利用類型下土壤0-20cm深度范圍內(nèi),隨土壤深度增加TOC、TN與兩種放射性核素其含量分布趨勢十分相似,TP與兩種放射性核素其含量分布趨勢差異較大。②總體上,TOC、TN含量與兩種放射性核素含量之間相關(guān)關(guān)系顯著,其中在非耕地中TOC、TN含量與兩種放射性核素含量之間均有明顯的相關(guān)關(guān)系,在農(nóng)耕地中TOC、TN含量與兩種放射性核素含量之間相關(guān)關(guān)系相對較弱。土壤1]P含量與兩種放射性核素含量之間的相關(guān)關(guān)系較為復雜,在不同土地利用類型下其相關(guān)關(guān)系未出現(xiàn)一定規(guī)律性,但TP含量與pH值相關(guān)性較為顯著。(3)不同土地利用類型下土壤機械組成及其與土壤放射性核素相關(guān)關(guān)系差異明顯。主要表現(xiàn)為：①5-2mm粒級土壤水穩(wěn)性團聚體含量與兩種放射性核素含量之間相關(guān)關(guān)系明顯,土壤水穩(wěn)性團聚體平均重量直徑與兩種放射性核素含量之間也有顯著相關(guān)關(guān)系。②對土壤顆粒粒徑百分含量與放射性核素含量進行相關(guān)性研究發(fā)現(xiàn),土壤砂粒百分含量與兩種放射性核素含量之間有顯著正相關(guān)關(guān)系,土壤粉粒百分含量與兩種放射性核素含量之間呈現(xiàn)負相關(guān)關(guān)系,土壤黏粒百分含量與兩種放射性核素含量之間呈現(xiàn)負相關(guān)關(guān)系。③不同土地利用類型下土壤顆粒粒徑重量分形維數(shù)大小與兩種放射性核素含量之間呈現(xiàn)明顯反相關(guān)關(guān)系。
[Abstract]:The hilly region of red soil in southern China is located in the subtropical region. The erosion of high intensity rainfall, leaching and intense biological cycle have a significant effect on the soil quality, resulting in soil quality degradation. The degradation of soil quality leads to the decrease of soil fertility and the change of soil structure. In the process of soil fertility reduction caused by erosion, soil organic matter and soil particle composition changed obviously. Therefore, understanding soil fertility is of great significance for rational land planning, effective management and sustainable development of agriculture. In view of the strong adsorption between radionuclides and soil organic colloids and soil particles, it is of great theoretical significance to explore the relationship between radionuclides and soil fertility factors in the qualitative evaluation of soil quality. In this paper, a small watershed near Chayuanshan, Yujiang County, Jiangxi Province was selected as the research object. By means of field investigation, physical and chemical analysis of samples and determination of radionuclides, soil radionuclide 137Csf210Pbex and soil physicochemical indexes (TOC) TNTPand soil aggregates were studied. The correlation between soil granularity and soil size was analyzed, and the following results were obtained: (1) Land use type had a significant effect on the distribution and change characteristics of 137Cs and 210pbex in soil profile. The migration of two radionuclides in soil is very similar. The main results were as follows: the content of 137Csf210Pbex in non-cultivated land decreased exponentially with the increase of soil depth in the range of 0-20cm depth, and the content of 137Csf210Pbex in cultivated land was relatively uniform with the increase of soil depth in the range of 0~20cm depth. The results showed that the distribution and migration of 137Cs and 210pbex in soil were similar. 2) the distribution of nutrient elements and the correlation between nutrient elements and soil radionuclides in different land use types were significantly different. The main results are as follows: (1) in the range of soil 0-20cm depth under different land use types, With the increase of soil depth, the distribution trend of TOCN TN and two radionuclides is very similar. The distribution trend of TP and two radionuclides is quite different. 2. There is a significant correlation between TOC TN content and two kinds of radionuclides. 2 in general, there is a significant correlation between TOC TN content and two kinds of radionuclides. There was a significant correlation between TOC TN content and two kinds of radionuclides in non-cultivated land, but the correlation between TOC TN content and two radionuclides content was relatively weak in farming land. The correlation between soil P content and radionuclide content is complex, and there is no regularity in the correlation between soil P content and radionuclide content under different land use types. However, the correlation between TP content and pH value was significant. 3) soil mechanical composition and its correlation with soil radionuclides were significantly different under different land use types. The correlation between the content of water-stable aggregates and the contents of two kinds of radionuclides is obvious. There was also a significant correlation between the average weight diameter of soil water-stable aggregates and the contents of two radionuclides. There was a significant positive correlation between soil sand content and two kinds of radionuclides, and a negative correlation between soil silt content and two kinds of radionuclides. There was a negative correlation between soil clay content and two kinds of radionuclides. 3 there was a significant inverse correlation between the fractal dimension of soil particle size and the content of two radionuclides under different land use types.
【學位授予單位】：南京師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S158

【引證文獻】

相關(guān)會議論文 前1條

1 張信寶;賀秀斌;文安邦;齊永青;伏介雄;;侵蝕泥沙研究的137Cs核示蹤技術(shù)[A];中國水力發(fā)電工程學會水文泥沙專業(yè)委員會第六屆學術(shù)討論會論文集[C];2005年

，

本文編號：1794281