自制环保土农药防治水稻病虫

自己动手制作环保土农药防治水稻病虫，不仅能降低生产成本．避免或减轻环境污染，而且效果良好。下面介绍几种水稻环保土农药的制作方法： 1．每667平方米（1亩）用干草木灰20．25公斤、生石灰15～20公斤、硫黄粉0．5～1公斤。三者混合均匀，在上午稻株露水未干时撒施．能有效防治稻瘟病。但在扬花期间不能施用此药，否则会影响授粉，降低结实率。

自制防治水稻病虫的环保土农药

自己动手制作环保土农药防治水稻病虫，不仅能降低生产成本，避免或减轻环境污染，而且效果良好。下面介绍几种水稻环保土农药的制作方法：

几种水稻环保土农药的制作方法

自己动手制作环保土农药防治水稻病虫，不仅能降低生产成本，避免或减轻环境污染，而且效果良好，下面介绍几种水稻环保土农药的制作方法。

太湖竺山湖环保疏浚土污染程度及特征评价分析

对太湖竺山湖区域的底泥进行了环保疏浚勘察,初步进行了野外勘察分层,大致分为三层:污染层、过渡层和正常层。分析了太湖竺山湖底泥沉积特征,选取代表性的土层采取原状土样和化学样品,进行了物理力学指标和化学指标的测试,并对底泥的指标进行了统计分析。利用内梅罗污染指数法对环保疏浚底泥进行了污染程度及污染类型的评价分析,从而使污染底泥环保疏浚厚度有据可依。

环保式土围堰快速施工工法

传统的土围堰施工容易造成水体二次污染,本文结合工程案例提出环保式土围堰快速施工工法。根据设计断面,优化结构,分期施工,并采取防污染措施,有效解决了水源保护区土围堰施工的环境保护问题,同时缩短了工期,取得了良好的社会效益和经济效益。

电力系统土水试验发展趋势

随着电力工业建设迅猛发展 ,建设中的岩土工程问题对土水试验提出了新的内容和要求。本文就多年来在工作中遇到的岩土工程中有普遍意义的四个问题进行初步探讨 :1 土工合成材料的应用与测试 ;2 粉煤灰的综合利用与试验 ;3 有关土水环保的试验 ;4 计算机技术在土工试验中的应用及土工测试技术的发展。

Analysis on Countermeasures of Water and Soil Conservation and Eco-environment Construction in China

With economy development,human destruction of eco-environment is deteriorating,which has become a key treatment nationwide.What＇s more,eco-environment construction is proceeding and multi-eco-environment projects are developing.Water and soil conservation and eco-environment construction should be a strategic task long-term insisted on,which is a part of agricultural construction.The research analyzed the relationship between water and soil conservation with eco-environment,concluded the process of ecological civilization construction in promoting water and soil conservation,and proposed countermeasures,laying foundation for water and soil conservation and ecological construction.

Phytoremediation of heavy metal polluted soils and water:Progresses and perspectives

Environmental pollution affects the quality of pedosphere,hydrosphere,atmosphere,lithosphere and biosphere.Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources.Phytoremediation,being more cost-effective and fewer side effects than physical and chemical approaches,has gained increasing popularity in both academic and practical circles.More than 400 plant species have been identified to have potential for soil and water remediation.Among them,Thlaspi,Brassica,Sedum alfredii H.,and Arabidopsis species have been mostly studied.It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come.This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources.

Microbial activity and community diversity in a variable charge soil as affected by cadmium exposure levels and time

Effects of cadmium （Cd） on microbial biomass, variable charge soil （Typic Aquult） using an incubation study activity and community diversity were assessed in a representative Cadmium was added as CdCNO3）2 to reach a concentration range of 0-16 mg Cd/kg soil. Soil extractable Cd generally increased with Cd loading rate, but decreased with incubation time. Soil microbial biomass was enhanced at low Cd levels （0.5-1 mg/kg）, but was inhibited consistently with increasing Cd rate. The ratio of microbial biomass C/N varied with Cd treatment levels, decreasing at low Cd rate （〈0.7 mg/kg available Cd）, but increasing progressively with Cd loading. Soil respiration was restrained at low Cd loading （〈1 mg/kg）, and enhanced at higher Cd levels. Soil microbial metabolic quotient （MMQ） was generally greater at high Cd loading （1-16 mg/kg）. However, the MMQ is also affected by other factors. Cd contamination reduces species diversity of soil microbial communities and their ability to metabolize different C substrates. Soils with higher levels of Cd contamination showed decreases in indicator phospholipids fatty acids （PLFAs） for Gram-negative bacteria and actinomycetes, while the indicator PLFAs for Gram-positive bacteria and fungi increased with increasing levels of Cd contamination.

Exploration of Water and Soil Conservation's Function in Construction of Eco-environment

Eco-environment lays foundation for human existence and development, and social and economy evolvement. Therefore, it is a fundamental principle to pro- tact and construct eco-environment and achieve sustainable development. With ur- ban development, and destruction on natural environment, however, the issue of water and soil losses has become a serious problem, affecting people＇s life and production. The research, therefore, explored the role of water and soil conservation in ecological civilization construction, including bomprehensive treatment of water storage and sand reduction, improving agricultural structure and advancing rural econ- omy, relieving the conflict between supply and demand of water resources, improv- ing eco-environment in mountainous regions and accelerating eco-construction.

Application of the ISCST3 model for predicting PCDD/F concentrations in agricultural soil in the vicinity of a MSWI plant in China

Based on the Industrial Source Complex Short-Term Version 3 （ISCST3） model, a simplified modeling approach was developed to predict concentrations of congeners of polychlorinated-p-dioxins and dibenzofurans （PCDD/Fs） of agricultural soil, within a radius of 3 kin from a municipal solid waste incinerator （MSWI） plant after its 4-year operation in Hangzhou, China. Comparisons were made between the measured and estimated congener-specific concentrations and the international-toxic equivalent （I-TEQ） values of soil samples with respect to distance from the stack. The results indicate that the predictions of soil PCDD/F concentrations and K-TEQ values were generally lower than their observations, and that the higher the degree of underestimation seems, the greater the further downwind one gets. Nevertheless, most of the predictions were in good agreement with the trend of measured ones and were within a factor of ten for samples located within 1 kin of the plant. Besides, analysis of contributions of various deposition pathways confirms that in addition to wet particle deposition, the dry gaseous deposition is essential for realistic prediction of PCDD/F depositions to soil, especially for tetra- and penta-chlorinated dioxins.

Surfactant-Enhanced Phytoremediation of Soils Contaminated with Hydrophobic Organic Contaminants:Potential and Assessment

Phytoremediation is becoming a cost-effective technology for the in-situ clean up of sites polluted with hydrophobic organic contaminants （HOCs）. The major factors limiting phytoremediation are the mass transfer, rate of plant uptake, and microbial biodegradation of HOCs. This article discusses the potential of surfactants to enhance desorption, plant uptake, and biodegradation of HOCs in the contaminated sites. Positive effects of surfactants on phytoremediation have been recently observed in greenhouse studies. The presence of some nonionic surfactants including polyoxyethylene sorbltan monooleate （Tween 80） and polyoxyethylene（23）dodecanol （Brij35） at relatively low concentrations resulted in significant positive effects on phytoremediation for pyrene-contaminated soil. However, the anionic surfactant （sodium dodecyl sulfate, SDS） and the cationic surfactant （cetyltrimethylammonium bromide, CTMAB） were not useful because of their phytotoxicity or low efficiency for surfactant-enhanced phytoremediation （SEPR）. The mechanisms of SEPR for HOC-contaminated sites were evaluated by considering experimental observations. In view of concerns about the cost effectiveness and toxicity of surfactants to plants, more research is needed to enhance the use of SEPR technology.

ECO-ENVIRONMENT CHANGE AND SOIL EROSION PROCESS IN THE RECLAIMED FORESTLAND OF THE LOESS PLATEAU

Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm waterstable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength decreased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable aggregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change of eco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.

A review of soil and water conservation in China

The preservation and sustainable development of soil and water resources isone of the basic principles for the development of China. Throughout the course of history, all thesocial improvement and economic development are deeply concerned with soil loss and ecologicalenvironmental protection. It is now a common sense that soil and water conservation is the safetyinsurance for national ecology and its development. For the past long period of time, soil and waterloss has been recognized as 'the No.1 killer' to the ecological environment. The nation is on thestags of the critical conditions for its development. China has massive mountain and upland areawith complicated geological conditions and accelerated human destruction and serious soil and waterloss. Based on rich historical documents, renovating experience and detailed analysis of the datacollected in field experiments and field surveys for soil and water conservation, this paper aims toreview the general characteristics of soil and water loss, to explore the relationship between soiland water conservation and sustainable economic development, and to provide relevant strategies forsoil and water conservation in China.

Effects of indigenous woody plantations on total nutrients of mine spoil in Singrauli Coalfield,India

A study was conducted on high-density young plantations of three native trees （Albizia lebbeck, Albizia. procera and Tectona grandis） and one native woody grass species （Dendrocalamus strictus） to examine their influence on total nutrient concentrations of coal mine spoil during early phase of plantation establishment. Soil samples were analyzed for total organic carbon （SOC）, Kjeldahl nitrogen （TKN） and phosphorus （TP） at spoil depths of 0-10 and 10-20 cm under 4- and 5-year-old plantations of all species. A significant effect on concentrations of total SOC, TKN and TP were observed due to plantation age, species and soil depth. However, corresponding con- centrations （SOC, TKN and TP） were substantially lower at spoil profile of 10-20 cm. In comparison, plantation ofA. lebbeck showed greater SOC and nutrient concentrations followed by D. strictus, A. procera and T. grandis, respectively. Therefore, present study clearly indicates attributing qualities of plantation towards improving redeveloping soil of mine spoil varied with species.

Dust source of the Holocene loess-soil and pedogenic environmental changes in the upper Huaihe River

Based on field surveys,soil samples were collected at the YPC site,Yuzhou City,Henan Province for analysis of contents of major and trace elements and their variations with XRF and comparison with the curves of magnetic susceptibility,pH value distribution,loss on ignition and particle-size distribution.It was concluded that the dust source of loess in the upper reaches of the Huaihe River Basin was different from that in the Loess Plateau.And the Holocene pedogenic environmental changes in the upper reaches of the Huaihe River Basin were revealed.

The environment of coal mining areas and the economic evaluation of the land reclamation

The environment impact of the coal resources mining was analyzed. The method of economic evaluation for the coal mining was established to analyze land destruction. The opportunity cost method was used to quantitatively analyze and estimate the economic loss of the land destruction by coal mining. At the same time, the dump land reclamation of the Yuanbaoshan Open Pit was taken as an example to evaluate environmental and economical benefit with the method of economic evaluation for the coal mining areas land reclamation.

Effect of Earthworm(Pheretimasp.) Density on Revegetation of Lead/zinc Metal Mine Tailings Amended with Soil

The objective of this study was to investigate the ef- fects of earthworm density on the availability of nutrients and heavy metals in metal contaminated soils.Pb/Zn mine tailings were mixed throughly with a red yellow podzolic soil at the ratio (w/w) of 75:25.Earthworms (Pheretima sp.) were introduced to the mixture at four different densities,zero,three,six and nine individuals per pot planted with ryegrass (Loliun multiflorum). The results indicated that earthworm activity significantly en- hanced ryegrass shoot biomass.However,as denser earthworm population was introduced,shoot biomass tended to decrease. Earthworm activity significantly increased soil pH and availability of N,P and K in the tailings and soil mixture.There was a general tendency that uptake of Zn by ryegrass increased after earthworm inoculation,although the increase in extractable Zn in tailings and soil mixture was not significant.On the contrary,there seemed to be a lower uptake of Pb by ryegrass under earthworm inoclation, despite the fact that higher extractable Pb concentrations were observed.The present project indicated that the improved growth of ryegrass was due to improved nutrient availability and other soil conditions,by inoculation of earthworms at an appropriate rate.Further studies are needed to illustrate the relationship be- tween metal availability and earthworm activity in the field.