模拟酸雨及其活化Al~（3＋）构成的复合污染对中小型土壤动物的毒杀效果

酸雨可引起土壤中铝离子的活化而造成铝毒问题,因此酸雨及其活化的金属铝离子势必造成对土壤中小型动物的复合污染与影响。为此,通过室内模拟试验,研究3种优势土壤动物直接暴露在4种不同酸度的模拟酸雨和4种不同铝离子浓度梯度组合而构成的复合污染处理条件下的死亡率,以探明酸雨通过降低土壤酸度同时活化Al3＋对土壤动物的叠加影响效应。研究结果表明：弹尾目、线虫、蜱螨目等土壤动物直接暴露在酸水和铝离子的复合溶液中,其死亡率总体上均会随着酸水pH值的降低和Al3＋离子浓度的升高而增加。通过单因素和双因素方差分析还发现,不同类群的土壤动物对模拟酸雨pH和溶液中Al3＋含量的敏感性各不相同,其中酸水和铝离子复合胁迫对线虫和蜱螨目动物死亡率的影响并没有表现出明显的交互作用,但对弹尾目土壤动物死亡率存在显著的交互作用影响。     

Environmental fate of glyphosate and aminomethylphosphonic acid in surface waters and soil of agricultural basins

Argentinian agricultural production is fundamentally based on a technological package that combines no-till and glyphosate in the cultivation of transgenic crops. Transgenic crops (soybean, maize and cotton) occupy 23 million hectares. This means that glyphosate is the most employed herbicide in the country, where 180–200 million liters are applied every year.     

Institutions,policies and soil degradation: theoretical examinations and case studies in Southeast China

Abstract

Southeast China is one of the severe soil degradation areas in China. This paper theoretically examines the impact of some important institutional arrangements and policies, like land management pattern, the rural off-farm employment, land property change and changes in prices of agricultural products, on soil degradation in this area. It further conducts some case studies to confirm the potential relationship between the institutions & policies and soil degradation, applying the surveyed and the second hand data. The paper at last makes some conclusions and proposes some suggestions on how to promote soil conservation by improving the ways of policy decision-making and the effects of policies on land use.     

Soil sterilization affects aging-related sequestration and bioavailability of p,p′-DDE and anthracene to earthworms

Laboratory experiments investigated the effects of soil sterilization and compound aging on the bioaccumulation of spiked p,p′-DDE and anthracene by Eisenia fetida and Lumbricus terrestris. Declines in bioavailability occurred as pollutant residence time in both sterile and non-sterile soils increased from 3 to 203 d. Accumulation was generally higher in sterile soils during initial periods of aging (from 3-103 d). By 203 d, however, bioavailability of the compounds was unaffected by sterilization. Gamma irradiation and autoclaving may have altered bioavailability by inducing changes in the chemistry of soil organic matter (SOM). The results support a dual-mode partitioning sorption model in which the SOM components associated with short-term sorption (the ‘soft’ or ‘rubbery’ phases) are more affected than are the components associated with long-term sorption (the ‘glassy’ or microcrystalline phases). Risk assessments based on data from experiments in which sterile soil was used could overestimate exposure and bioaccumulation of pollutants.     

Formation Process and Amelioration of the Loess Plateau in China

Abstract

Based on the formation process of the Loess Plateau, the characteristics comparison between loess and ancient soil and the located materials of spore- pollen, ancient stone artifact, history, geography and soil erosion, the analysis reveals that the present state serious soil erosion in Loess Plateau, instead of being a natural geologic course, is a consequence of destruction of vegetation, irrational land utilization and the direct destruction of soil permeability and anti-erosion ability, esp. anti-scourability. The water and soil conservation measures, with the twenty-eight-word amelioration principle as the core, are the basis for exploiting and improving water and soil resources of the Loess Plateau so as to harness the Huanghe (the Yellow River).     

土壤对污染物的缓冲性研究进展

本文阐述了土壤对污染物的缓冲特性的概念，研究土壤对污染物缓冲性的目的和意义、历史、现状和前景，为土壤污染与防治提供了一定的理论依据。     

庞泉沟自然保护区土壤呼吸空间分异性影响因素探测

土壤呼吸是维持全球碳平衡的重要过程.以庞泉沟自然保护区为研究区域,基于实地测量的土壤呼吸（R_s）数据,结合海拔（ELE）、土壤温度（T）、土壤水分（SWC）、归一化植被指数（NDVI）、坡度（slope）、土壤全碳（C）、总氮（N）和土壤容重（BD）,运用地理探测器模型分析了R_s空间分异的主要驱动力及其交互作用.结果表明：①研究区R_s及其影响因子的空间变异均为中等变异.R_s与NDVI、T和土壤N呈极显著正相关（P<0.01）,与ELE、slope和SWC呈极显著负相关（P<0.01）,R_s与BD显著负相关（P<0.05）,与C相关性不显著（P>0.05）.②NDVI和T构成的多元线性模型可以解释R_s空间分异的64.3%.③ELE、T和NDVI为研究区R_s空间分异性的主导驱动力,可以解释64%、59%和48%的空间变异.④双因子的交互作用均能增强对R_s空间分异性的解释力,最大交互因子分别为ELE∩BD （q=0.73）和T ∩ slope （q=0.74）.因此,在R_s的估算过程中,结合地形及环境条件,应考虑多种因子之间的交互作用.     

Measurement of the scarcity of soil in agriculture

The paper defines the concept of land degradation and costs and effects of soil erosion. Through the concept of optimal levels of soil erosion, a conceptual model of the social costs of soil degradation is elaborated. The discussion focuses on the measurement aspects of the economic scarcity of soil in the agriculture sector. Reliable estimates of the true impacts of soil degradation can only be made if data on marginal damage costs and marginal conservation costs are available. The different scarcity indicators are evaluated and competitive land rental prices are considered as appropriate in indicating soil scarcity in agriculture.     

铬渣对地下水、土壤、蔬菜污染机制的研究

本文对沈阳市化工石油厂（现为石油化工二厂），在６０年代产生废铬渣６０００余吨．由于铬渣堆放不合理，经过风吹雨淋造成了周围环境污染，导致了沈海菜田的地下水．土壤、蔬菜受到严重污染．通过专项调研，全面剖析了铬渣中的六价铬对地下水、土壤、蔬菜的污染规律．     

土壤微生物呼吸热适应性与微生物群落及多样性对全球气候变化响应研究

土壤微生物呼吸热适应性被认为是决定陆地生态系统对全球变暖反馈作用的潜在重要机制,可能显著改变未来的气候变化趋势,然而,土壤微生物群落结构变化如何引起土壤微生物呼吸热适应性的研究目前尚存争议.该文针对气候变化对土壤微生物呼吸的影响研究,梳理了当前对土壤微生物呼吸的热适应性是否存在的争议和不同观点与结论,综述了气候变化对土...