西部开发中宁南旱区畜牧业的发展战略——以海原县为例

依据宁南旱区的自然资源特点 ,通过对宁南旱区畜牧业现状的深入分析 ,提出了在西部开发中宁南旱区畜牧业发展战略 :退耕还草 ,改善生态环境 ;优化畜群结构 ,加强品种改良力度 ;努力改善畜牧业赖以发展的基础条件 ;优化资源配置 ,提高经营的综合效益 ;大力发展社会化服务体系 ,走可持续发展道路     

淮北变性土性状特点对其生产性能的影响及农业利用对策

本研究基于黄淮海平原多个变性土剖面分层土壤样品的土壤理化性状分析数据,对其肥力特征、生产性能以及培肥改良措施进行了系统研究。相关结果表明,机械组成中粘粒含量高、质地粘重、土壤结构和孔隙性差是变性土主要物理性状特征,受其影响,土壤表现出耕作性能差、蓄水能力弱、保水性能不强等特点;化学性状主要表现为有机质含量不高、质量差,土壤氮素水平仍较低,耕层土壤速效磷含量分异加大,土壤速效钾含量缓慢降低,土壤CEC含量较高,土壤保肥性能强,但供肥性能较差等特点。这些性状特点对土壤生产性能的影响主要表现在土壤适耕期短,易受旱、涝(渍)灾害的危害,土壤有效养分低、营养失调,钙质结核影响土壤蓄水能力和水分运行以及作物根系生长等方面。指出:(1)增加土壤有机质,改良土壤理化性质;(2)合理施肥,促进土壤养分平衡;(3)改进耕作、灌溉技术,调控土壤水分状况等是培育变性土肥力质量、提高土壤生产性能的关键性措施。     

干旱灾害背景下宁夏避灾农业经营模式的地域构架

宁夏农业生态环境的干旱化趋势,已经成为制约区域农业可持续发展的主要障碍。在干旱灾害环境背景下,基于区域内部环境质量的非均质性,初步提出并构建了宁夏避灾农业经营模式,即引黄灌区高效集约与规模经营的避灾农业亚模式和南部山区高效利用与综合发展的避灾农业亚模式。较以往农业发展模式,避灾农业生态模式更具经济上易于接受,运行上易于操作,收益上高效的特点,特别是对于优化农业投资环境,实现区域可持续发展意义重大。     

毕节地区人口和经济因素对生态自然修复的影响

新疆南疆属于极端干旱生态脆弱带,土壤风蚀已严重制约着南疆绿洲农业的可持续发展。在分析了造成南疆绿洲区土壤风蚀主要因素的基础上,探讨了风蚀造成的危害,提出了保护、恢复与重建绿洲外缘的自然植被、加强绿洲内部防护林体系的建设、调整种植结构和进行农作物留茬覆盖等防治土壤风蚀的综合治理措施。     

新疆水土保持与可持续发展研究

新疆维吾尔自治区作为我国最大及地理位置重要的西北边陲省份，随着人口的增长区域开发进程的进一步加快，水土流失问题日趋严重，水土保持和可持续发展已成为其生态环境建设的重要课题。分析了新疆水土流失的现状、特点和成因以及存在的问题，从可持续发展角度提出了新疆水土保持的对策和建议。     

毕节地区烤烟化学成分分析

对毕节烟区8个主产烟县所产烤烟烟叶C3L、C3F的10个常规化学成分进行了全面分析。结果表明:全区烤烟除钾离子和氯离子含量略偏低外,蛋白质、总氮、烟碱都处于合理水平,化学成分协调性好;县际间除氯离子(赫章、金沙平均最高,0.35%,威宁最低0.20%)、钾离子(大方1.84%,毕节市1.37%)和烟碱(金沙最高3.02%,赫章最低1.62%)差异较大外,其余化学成分差异不太大。     

Comparison of Soil Clean-up Standards for Trace Elements Between Countries: Why do they differ? (9 pages)

Goal, Scope and Background

In the nineteen nineties most European countries issued legislation on soil protection, including soil contamination. In the case of a presumed contamination, soil investigation mostly follows a stepwise approach starting with a preliminary investigation, then an in-depth investigation and, finally, remediation. Soil clean-up standards are often foreseen as trigger criteria to determine the need for an in-depth soil investigation or for remediation. There are however large differences in soil clean-up standards. This is partly because of the different roles of soil clean-up standards in each legislative framework and partly because of differences in the soil clean-up standard (SCS) derivation procedures. Despites these differences there are large similarities in the concepts of the derivation procedures for clean-up standards. A better understanding of the differences in clean-up standards is needed. In order to clarify the variation, the background of the clean-up standards for a selected number of countries was investigated. The objective of this paper is to investigate the underlying reason why country-wide generic soil and groundwater clean-up standards of eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) differ between the selected countries.

Main Features

To avoid misinterpretation of the differences in application of the clean-up standards, a short overview of the legislative role of clean-up standards is given first. Differences in model concepts and parameter values are discussed, followed by a comparison of the generic soil and groundwater clean-up standards for trace elements and a discussion on the sources of variation. The influence of the use of ecotoxicological criteria and data for the derivation of soil clean-up standards will be discussed in more detail. Selected countries were Canada, the Flemish Region (Belgium), France, Germany, Great-Britain, the Netherlands, Norway, Sweden, Switzerland and United States of America (USA).

Results and Discussion

When soil clean-up standards for eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) were compared between the selected countries differences of more than a factor 1000 arose. Notwithstanding the use of similar derivation procedures, differences were caused by the use of different software models with their specific input data, boundary conditions and applied protection criteria for humans and the ecology. Ecotoxicological criteria tend to lower the soil clean-up standard for the selected trace elements.

Conclusions

In the countries that are included in this study, clean-up standards are used is different ways, this is for the determination of the necessity for remediation or for the need for further soil investigation. This paper shows a wide variation in the clean-up standards, which has further implication on the decision for remediation or further investigation and, hence, the financial costs of soil management. All the clean-up standards have as primary goal the protection of human health. A number of countries also include the protection of the ecological function of the soil. Differences in selected software model, (standard) parameters values, selected human toxicological and ecotoxicological criteria, are reason for a substantial variation in the clean-up standards for trace elements.

Recommendations and Perspective

. Is this variation justified? The derivation of soil clean-up standards involves - besides scientific elements - political elements, like differentiation in landuse types (agricultural, residential, recreational, industrial), receptor at risk or protection level. It is obvious that harmonization of these elements will be complicated. However, a European action programme, like the thematic strategy for soil protection, could initiate this process of harmonization. Nevertheless, soil-clean-up standards could never be uniform over the whole of Europe because they include country specific elements (geographical, ethnological) and political decisions.     

宁夏林业生态建设固碳效应及其潜力估算

利用宁夏自治区第三次至第七次森林资源普查数据及林业生态建设工程数据,采用材积源生物量法分析研究了宁夏森林及林业生态建设工程的固碳能力和潜力。结果表明:"十五"和"十一五"林业生态建设与保护工程实施期间,宁夏自治区森林主要面积、蓄积量、森林总生物量和碳贮量等均呈增加趋势。林业生态建设与保护工程增加森林面积、天然林林分面积和人工林林分面积分别为18.30万hm2、0.88万hm2、5.76万hm2;增加活立木蓄积量、林分蓄积量分别为300.29万m3、267.48万m3,其中人工林林分蓄积量增加为207.24万m3。"十五"和"十一五"期间,宁夏林业生态建设与保护工程共增加森林碳贮量124.99万t,其中三北防护林工程、天然林保护工程和经济林工程合计增加森林碳贮量91.45万t。预计到2020年,宁夏森林总碳贮量将达到430.52万t。     

内蒙古自治区牧民收支情况分析——以锡林郭勒盟镶黄旗为例

基于对内蒙古锡林郭勒盟镶黄旗牧民家庭的入户调查数据,分析了2008、2009年西部地区牧民家庭的收入与消费结构。结果表明:牧民收入来源单一,以家畜出售为主,抗风险能力差;消费支出中饲草料购置比重最大,且增长迅速,其次是食品、教育、医疗等支出,住房方面政策补贴较多。牧民的收入与消费特点是由自然因素、市场因素、政策因素和自身因素共同决定的,基于此,提出了牧民提高收入、改善消费结构的对策建议:牧民要提高养殖技术,科学养殖,增加收入,且要转变消费观念,适度储蓄,增强抗风险能力;政府要加大对牧区的财政补贴力度,加强对牧民的教育、培训和医疗保健投入,提高牧民素质。     

明清诗人笔下的淮河灾荒

淮河原本是一条出路通畅,直接入海的河流,但黄河夺淮以后,淮河流域自然灾害极为频繁,本文以明清时期有关记载淮河流域灾荒的诗歌作为基本研究素材,较为系统地研究了明清两代淮河流域水灾、旱灾、潮灾、蝗灾等的基本概况和特征,对淮河两岸百姓生产生活的影响,同时,还对淮河流域的救灾进行探讨。