土壤碳固定是当前有关陆地生态系统碳循环与全球变化的地球表层过程研究的重要优先领域。国际社会对全球农业温室气体减排的需求,驱动着土壤学对土壤固碳容量与潜力、固碳与减排的过程与机理的前沿探索,并越来越呈现为一个独特的土壤学...土壤碳固定是当前有关陆地生态系统碳循环与全球变化的地球表层过程研究的重要优先领域。国际社会对全球农业温室气体减排的需求,驱动着土壤学对土壤固碳容量与潜力、固碳与减排的过程与机理的前沿探索,并越来越呈现为一个独特的土壤学新兴分支学科——固碳土壤学(Soil Science of C Sequestration)。本文围绕固碳土壤学的基本科学问题,回顾了最近10多年来,特别是最近5年来国内外关于土壤固碳研究的主要进展,讨论了固碳土壤学中的核心科学问题是土壤固碳容量与固碳作用的机理,论述了土壤物理保护、碳化学结合与碳化学转化稳定与固碳容量及稳定化的关系,提出了土壤-植物(作物)-微生物相互作用是当前固碳土壤学的前沿领域和深化方向,并结合国内对水稻土固碳的研究进展,提出了固碳土壤学的概念性框架,认为我国亟待加强固碳土壤学研究,深入探索我国农业经营管理特色下土壤固碳容量、过程、机理,丰富和发展农业土壤碳循环理论,并服务于全球变化生物学和国家碳管理。展开更多
Heavy metal pollution in agricultural soils has serious negative influence on human health. Concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni in top soils （0-20 cm） of greenhouses and farmlands from four main veg...Heavy metal pollution in agricultural soils has serious negative influence on human health. Concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni in top soils （0-20 cm） of greenhouses and farmlands from four main vegetable production areas Shouguang, Laiyang, Jinxiang, and Zhangqiu in Shandong Province, one of the most rapidly developing regions in China, were measured in this study. Shouguang is mainly occupied by greenhouse vegetables and the other three areas are mainly open field culture. Total of 149 soil samples were collected. The average concentrations of the eight heavy metals of the tested 149 soil samples were all below the threshold values according to ＂Farmland environmental quality evaluation standards for edible agricultural products （HJ332-2006）＂ of China. However, most of the studied heavy metals were present at higher concentrations than those of the natural background levels in local agricultural soils. Among the total 149 soil samples, 22 samples were contaminated by Cd, Ni, Cu, or Hg. Comparisons showed that the main pollution element in greenhouse vegetable soils was Cd, while that of open field vegetable soils was Cu. The results of principal components analysis （PCA） suggested that concentrations of Cr, As, and Ni were mainly controlled by parent rocks; Hg and Pb were affected by anthropogenic activities such as vehicle and industrial fumes and waste water irrigation. Meanwhile, concentrations of Cd, Cu, and Zn were affected mainly by the use of agrochemicals. Most of the heavy metals were positively correlated with each other in concentration. Appropriate measures should be taken to effectively control heavy metal levels in vegetable soils and thus protect human health.展开更多
文摘土壤碳固定是当前有关陆地生态系统碳循环与全球变化的地球表层过程研究的重要优先领域。国际社会对全球农业温室气体减排的需求,驱动着土壤学对土壤固碳容量与潜力、固碳与减排的过程与机理的前沿探索,并越来越呈现为一个独特的土壤学新兴分支学科——固碳土壤学(Soil Science of C Sequestration)。本文围绕固碳土壤学的基本科学问题,回顾了最近10多年来,特别是最近5年来国内外关于土壤固碳研究的主要进展,讨论了固碳土壤学中的核心科学问题是土壤固碳容量与固碳作用的机理,论述了土壤物理保护、碳化学结合与碳化学转化稳定与固碳容量及稳定化的关系,提出了土壤-植物(作物)-微生物相互作用是当前固碳土壤学的前沿领域和深化方向,并结合国内对水稻土固碳的研究进展,提出了固碳土壤学的概念性框架,认为我国亟待加强固碳土壤学研究,深入探索我国农业经营管理特色下土壤固碳容量、过程、机理,丰富和发展农业土壤碳循环理论,并服务于全球变化生物学和国家碳管理。
基金supported by the National Key Tech-nology R&D Program of China (2006BAD17B07,2006BDA07A13-1-2) the Staring Fund for Doc-tors of Shandong Academy of Agricultural Sciences,China (2006YBS015)
文摘Heavy metal pollution in agricultural soils has serious negative influence on human health. Concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni in top soils （0-20 cm） of greenhouses and farmlands from four main vegetable production areas Shouguang, Laiyang, Jinxiang, and Zhangqiu in Shandong Province, one of the most rapidly developing regions in China, were measured in this study. Shouguang is mainly occupied by greenhouse vegetables and the other three areas are mainly open field culture. Total of 149 soil samples were collected. The average concentrations of the eight heavy metals of the tested 149 soil samples were all below the threshold values according to ＂Farmland environmental quality evaluation standards for edible agricultural products （HJ332-2006）＂ of China. However, most of the studied heavy metals were present at higher concentrations than those of the natural background levels in local agricultural soils. Among the total 149 soil samples, 22 samples were contaminated by Cd, Ni, Cu, or Hg. Comparisons showed that the main pollution element in greenhouse vegetable soils was Cd, while that of open field vegetable soils was Cu. The results of principal components analysis （PCA） suggested that concentrations of Cr, As, and Ni were mainly controlled by parent rocks; Hg and Pb were affected by anthropogenic activities such as vehicle and industrial fumes and waste water irrigation. Meanwhile, concentrations of Cd, Cu, and Zn were affected mainly by the use of agrochemicals. Most of the heavy metals were positively correlated with each other in concentration. Appropriate measures should be taken to effectively control heavy metal levels in vegetable soils and thus protect human health.
