依靠科技进步 发展低碳农业

在全球携手应对气候变暖、减少温室气体排放的背景下,发展低碳经济是解决气候变化与经济发展矛盾的有效途径。通过描述气候变化、固碳减排对粮食安全、土壤碳汇、森林固碳、资源循环利用等影响和促进作用,深入分析发展低碳经济与可持续发展的关系,探讨如何在农业领域内开发高效循环生产体系,从而实现农业生产过程的固碳减排目的。由此,提出发展低碳农业是实现低碳经济的目标之一,它是一个复合技术体系,涉及了绿色农业、循环农业、生态文明、可持续发展理念。必须通过科学技术的突破,改造、提升低碳农业技术,改变农业现有的＂高能耗、高污染＂的生产状况,实现低碳生产、生活方式的转变。最后提出发展现代的低碳农业产业经济的对策和思考。     

农田土壤重金属污染状况及修复技术研究

重金属污染因具有毒性、易通过食物链在植物,动物和人体内累积,对生态环境和人体健康构成严重威胁。随着工业快速发展、农药及化肥的广泛使用,农田土壤重金属污染越来越严重,研究农田土壤重金属污染现状及修复技术对农产品安全具有重要意义。综合国内外农田土壤重金属污染状况,农田土壤重金属污染主要来源于固体废弃物堆放及处置、工业废物大气沉降、污水农灌和农用物质的不合理施用。该文综述了国内外有关农田重金属污染土壤修复技术（物理修复、化学修复、生物修复、农业生态和联合修复）的研究进展,并针对各种修复方法,阐述了其原理、修复条件、应用实例及其优缺点,重点论述了植物修复的机理和应用,提出了草本与木本联合修复可有效提高农田土壤重金属复合污染的修复效率,为农田土壤土壤重金属复合污染修复提出了新的途径。最后在对已有研究分析的基础上,提出了联合修复技术（如生物联合技术、物理化学联合技术和物理化学-生物联合技术）可以在一定程度上克服使用单一修复手段存在的缺点,可提高复合污染的修复效率、降低修复成本,未来应深入探索联合修复技术间的相互作用机理,以期为农田土壤重金属综合治理与污染修复提供科学依据。     

Changes in hydrology and salinity accompanying a century of agricultural conversion in Argentina

Conversions of natural woodlands to agriculture can alter the hydrologic balance, aquifer recharge, and salinity of soils and groundwater in ways that influence productivity and sustainable land use. Using a land-use change chronosequence in semiarid woodlands of Argentina's Espinal province, we examined the distribution of moisture and solutes and estimated recharge rates on adjacent plots of native woodlands and rain-fed agriculture converted 6-90 years previously. Soil coring and geoelectrical profiling confirmed the presence of spatially extensive salt accumulations in dry woodlands and pervasive salt losses in areas converted to agriculture. A 1.1-km-long electrical resistivity transect traversing woodland, 70-year-old agriculture, and woodland, for instance, revealed a low-resistivity (high-salinity) horizon between approximately 3 m and 13 m depth in the woodlands that was virtually absent in the agricultural site because of leaching. Nine-meter-deep soil profiles indicated a 53% increase in soil water storage after 30 or more years of cultivation. Conservative groundwater-recharge estimates based on chloride tracer methods in agricultural plots ranged from approximately 12 to 45 mm/yr, a substantial increase from the <1 mm/yr recharge in dry woodlands. The onset of deep soil moisture drainage and increased recharge led to >95% loss of sulfate and chloride ions from the shallow vadose zone in most agriculture plots. These losses correspond to over 100 Mg of sulfate and chloride salts potentially released to the region's groundwater aquifers through time with each hectare of deforestation, including a capacity to increase groundwater salinity to >4000 mg/L from these ions alone. Similarities between our findings and those of the dryland salinity problems of deforested woodlands in Australia suggest an important warning about the potential ecohydrological risks brought by the current wave of deforestation in the Espinal and other regions of South America and the world.     

A sustainability assessment of a high-yield agroecosystem in Huantai County,China

Sustainable agricultural development is a perennial issue for agricultural researchers, government managers, and policy makers worldwide, but especially in developing countries. In China, farms in Shandong Province epitomize modern agriculture and play a vital role in providing food for the burgeoning population. However, Chinese agriculture is being challenged by declining resources and environmental deterioration resulting from modern farming practices. China must establish an efficient agricultural sustainability index (ASI) to evaluate agricultural conditions and offer recommendations for sustainable development. Here, we use Huantai County, Shandong Province to test a regionalscale ASI from social, economic and ecological factors that includes 11 sustainability indicators. To further evaluate the complex agroecosystem, we employed the analytic hierarchy process (AHP) and AMOEBA methods to assess agricultural sustainability from 1982 to 2003. The results show that environmental problems, especially groundwater depletion, are limiting regional sustainable development.     

What motivates farmers to participate in sustainable agriculture? Evidence and policy implications

Sustained growth in agricultural productivity has become an ideal model and a political goal of agricultural development in China. Local participation is essential for the implementation of sustainable agriculture strategy. We conducted a case study in Hailun County, an important grain production base in China, to find ways to motivate farmers to participate in sustainable agriculture. We obtained data from semi-structured interviews of 98 households using participatory rural appraisal methods. Logistic regression models were used to explore factors that underlie farmers' attitudes towards agricultural production and their environmental awareness. Results indicated that low agricultural economic efficiency could result in less enthusiasm for agriculture among local farmers. This is a potential risk for China's food security and sustainable agricultural development. The backward development of the rural economy limited improvement of farmers' environmental awareness. Moreover, poor rural labour quality implied a lack of local participation in sustainable agriculture. Suggestions for sustainable agricultural development include establishment of a reasonable market and agricultural subsidy mechanisms, basic and vocational education for young adults, effective agricultural instruction and environmental education agencies and two-way communication mechanisms.     

农药内分泌干扰效应研究进展

农药作为农业生产过程中的一类重要生产资料,主要用作杀虫剂、杀菌剂和除草剂等。由于农药的大量使用,目前在各类农产品及各种环境介质中都能被检测到,对饮食健康和环境安全带来潜在危害。研究发现,许多农药为内分泌干扰物,其能够干扰人类和其他生物体的内分泌系统正常功能。本文在总结国内外相关研究的基础上,对农药内分泌干扰效应的作用机理及筛选模型进行总结,对有机氯、有机磷和拟除虫菊酯等各类农药的内分泌干扰效应研究进展进行综述,并提出深入探究农药致毒作用机制和低剂量下多种农药联合毒性是本领域的重要研究方向。     

Electrochemistry: as cause and cure in water pollution—an overview

This article reviews both the pollution by the electrochemical industry and the use of electrochemistry to clean water. Main pollutants include Pd, Cd, Ni, Hg and other metals and cyanide as well as organic pollutants. The cause for water pollution by electrochemistry is due to the effluents from different electrochemical industries such as mercury from chlor-alkali industry; lead, cadmium and mercury from battery industry; heavy metals and organic contaminants from electroplating wastes; contaminants from corrosion processes; and persistent organic pollutants from the synthesis and use of pesticides, dyes and pharmaceuticals. Most pollutants can be successfully eliminated or converted to non-toxic materials by methods based on the electrochemical principles. Electrochemical depolluting methods are mainly electrodialysis, electrocoagulation, electroflotation, anodic processes, cathodic processes and electrochemical advanced oxidation processes.     

Nanoscience in food and agriculture: research,industries and patents

High population rise and climate changes are increasing issues of agricultural production and food safety. Nanotechnology is finding revolutionary applications to improve agricultural and food systems, notably for better crop production and food preservation. Here we review research, industrial and patent trends of nanoscience in food and agriculture. In a literature survey, we found 44.6% publications in the nano-food research area during the years 2013–2015 and 59.09% publications in the nano-agriculture research area during 2012–2015. USA is leading in the development of nanotechnology firms with a maximum share of 75.5% of the total firms, followed by Germany and France with 8.10 and 4.74%, respectively. USA is leading in the nano-food research with 22 granted patents, whereas China is placed first in nano-agriculture research with 28 granted patents during assessment years 2011–2015. Nano-food research focused mainly on nano-food packaging with 76.84% contributions, whereas in nano-agriculture research, focus has been on nano-fertilizers with 90% contributions. Germany, France, Korea, Italy, Czech Republic, Slovenia and Slovak republic have more than 20% of dedicated nanotechnology firms. A growth of about 45% in nano-food patents has been observed for USA during 2011–2015, and China is leading in the nano-agriculture patents with an increase of 60.7% during 2012–2015.     

Levels and distributions of organochlorine pesticides in the soil–groundwater system of vegetable planting area in Tianjin City,Northern China

To study the influence of long-term pesticide application on the distribution of organochlorine pesticides (OCPs) in the soil–groundwater system, 19 soil samples and 19 groundwater samples were collected from agricultural area with long-term pesticide application history in Northern China. Results showed that the composition of OCPs changed significantly from soil to groundwater. For example, ∑DDT, ∑HCH, and ∑heptachlor had high levels in the soil and low levels in the groundwater; in contrast, endrin had low level in the soil and high level in the groundwater. Further study showed that OCP distribution in the soil was significantly influenced by its residue time, soil organic carbon level, and small soil particle contents (i.d. <0.0002 mm). Correlation analysis also indicates that the distribution of OCPs in the groundwater was closely related to the levels of OCPs in the soil layer, which may act as a pollution source.     

Hydrogeochemical processes identification and groundwater pollution causes analysis in the northern Ordos Cretaceous Basin,China

It is necessary to identify the hydrogeochemical processes and analyze the causes of groundwater pollution due to the lack of knowledge about the groundwater chemical characteristics and the endemic diseases caused by groundwater pollution in the northern Ordos Cretaceous Basin. In this paper, groundwater chemical facies were obtained using the piper trilinear diagram based on the analysis of 190 samples. The hydrogeochemical processes were identified using ionic ratio coefficient, such as leaching, evaporation and condensation. The causes and sources of groundwater pollution were analyzed by correspondence analysis, and the spatial distribution and enrichment reasons of fluoride ion were analyzed considering the endemic fluorosis emphatically. The results show that leaching, evaporation and condensation, mixing, and anthropogenic activities all had significant impact on hydrogeochemical processes in the study area. However, cation exchange and adsorption effects were strong in the S2 and S3 groundwater flow systems, but weak in S1. Groundwater is mainly polluted by Mn and COD_Mn in the study area. The landfill leachate, domestic sewage, and other organic pollutants, excessive use of pesticides and fertilizers in agriculture, and pyrite oxidation from long-term and large-scale exploitation of coal are the sources of groundwater pollution. The S1 has the highest degree of groundwater pollution, followed by S2 and S3. High concentration of fluoride ion is mainly distributed in the north and west of study area. Evaporation and condensation and groundwater chemistry component are the most important causes of fluoride ion enrichment. The results obtained in this study will be useful for understanding the groundwater quality for effective management and utilization of groundwater resources and assurance of drinking water safety.     

Reduction in global habitat loss from fossil-fuel-dependent increases in cropland productivity

Terrestrial biodiversity loss and climate change, driven mainly by loss of habitat to agriculture and fossil fuel (FF) use, respectively, are considered among the world's greatest environmental threats. However, FF-dependent technologies are currently essential for manufacturing synthetic nitrogen fertilizers (SNFs) and synthetic pesticides (SPs) critical to increasing agricultural productivity, which reduces habitat loss. Fossil fuel use increases CO₂ levels, further enhancing agricultural productivity. Based on estimates of global increases in yields from SNFs, SPs, and atmospheric CO₂ fertilization, I estimated that FF-dependent technologies are responsible for at least 62.5% of current global food production (GFP) from cropland. Thus, if FF use is eschewed in the future, maintaining current GFP means croplands would have to increase from 12.2% of global land area (GLA) excluding Antarctica to 32.7%. The additional 20.4% of GLA needed exceeds habitat lost currently to cropland (12.2% of GLA) and cumulative conservation areas globally (14.6% of GLA). Thus, although eliminating FF use could reduce climate change, its unintended consequences may be to significantly exacerbate biodiversity loss and indirectly increase food costs, reducing food security which, moreover, disproportionately affects the poor. Although it may be possible to replace SNFs and SPs with FF-free technologies, such substitutes have not yet been demonstrated to be sufficiently economical or efficient. In the interim, meeting global food demand and keeping food prices affordable would increase habitat conversion and food prices. These trade-offs should be considered in analyses of climate change policies.     

土壤多环芳烃污染根际修复研究进展

多环芳烃(polycyclicaromatichydrocarbons,PAHs)是环境中普遍存在的具有代表性的一类重要持久性有机污染物,具“三致性”、难降解性,在土壤环境中不断积累,严重危害着土壤的生产和生态功能、农产品质量和人类健康。修复土壤多环芳烃污染已成为研究的焦点。根际修复是利用植物-微生物和根际环境降解有机污染物的复合生物修复技术,是目前最具潜力的土壤生物修复技术之一。对国内外学者近年来在土壤多环芳烃污染根际修复的效果、根际修复机理和根际修复的影响因素方面的研究进展作了较系统的综述,并分别分析了单作体系、混作体系、多进程根际修复系统和接种植物生长促进菌根际修复系统对土壤多环芳烃的修复效果。指出根际环境对PAHs的修复主要有3种机制:根系直接吸收和代谢PAHs;植物根系释放酶和分泌物去除PAHs,增加根际微生物数量,提高其活性,强化微生物群体降解PAHs。并讨论了影响根际修复PAHs的环境因素如植物、土壤类型、PAHs理化性质、菌根真菌以及表面活性剂等。植物-表面活性剂结合的根际修复技术、PAHs胁迫下根际的动态调节过程、运用分子生物学技术并结合植物根分泌物的特异性筛选高效修复植物以及植物富集的PAHs代谢产物进行跟踪与风险评价将成为未来研究的主流。     

Liability for groundwater contamination from pesticides

This paper considers the extent to which farmers should be held liable for groundwater contamination from agricultural pesticides. The problem is first viewed as a standard tort and then as a case of product liability, where the question of shifting liability to the manufacturer of the pesticide is considered. The results suggest that, when the problem is viewed as a case of product liability, farmer exemptions from liability can still lead to efficient levels of pesticide use, provided appropriate application methods keyed to site characteristics can be ensured through regulation or other means.     

有机肥中重金属特征及其控制技术研究进展

随着工业的快速发展,农药、肥料及地膜等系列农用化学物质的广泛使用,农田土壤重金属污染越来越严重。重金属进入土壤后,其难移动性导致大量积累,造成土壤环境污染,影响植物生长,危及人类的健康。有机肥是我国农业生产中非常重要的肥料,其来源也十分广泛。施用有机肥是提高作物产量的必要措施,同时也是土壤重金属的主要输入途径之一,研究有机肥的重金属特征及其有关控制技术对农产品安全和有机废弃物的再利用具有重要意义。文章就畜禽排泄物堆肥、污泥堆肥、生活垃圾堆肥和沼肥等主要有机肥料的重金属来源、含量以及不同溯源有机肥料对土壤中重金属有效性的影响进行综述,重点介绍了畜禽排泄物堆肥中重金属含量和饲料添加剂之间的关系,为农田土壤重金属污染防治和农产品安全提供科学依据。除从有机肥的源头控制重金属外,文章主要介绍了化学法、生物吸附法、生物淋滤法和电化学法等重金属控制技术,针对各种控制方法,阐述了其原理、应用实例、优缺点及研究进展情况,提出了解决有机肥重金属污染问题的思路和方法,为有机肥料的资源化利用提供了参考。最后指出,为了实现养殖业与种植业的安全链接,除选用重金属含量低的有机肥,通过相关技术有效控制有机肥中的重金属外,还要注重肥料用量、施肥时间、施肥技术的合理选择,从最大程度上避免有机肥料给作物和人类带来的副作用。     

再生水回灌地下水环境安全风险评价技术方法研究

再生水回灌是水资源管理的一条有效途径,也是污水再生利用的重要发展方向。然而,当再生水以农灌、土壤含水层处理（SAT）、河湖入渗和井灌等方式进行地下水回灌时,不可避免的会在回补地下水的过程中造成对地下水环境的污染风险。针对不同回灌方式建立适用于我国的再生水回灌地下水环境安全风险评价技术体系至关重要。借鉴国内外地下水污染风险评价方法,综合分析再生水回灌对地下水产生风险的关键环节,采用层析分析法,从回灌水特征污染物特性、回灌区地下水固有脆弱性以及回灌工程布设方式3个方面,针对地表灌溉、河湖入渗和井灌3种回灌方式,建立了包含污染物浓度水平、分配系数、溶解度、半衰期、半致死剂量、地下水埋深、降雨入渗补给量、地形坡度、土壤介质、包气带介质、含水层介质、含水层厚度、回灌强度、回灌周期、回灌水停留时间以及取水点与回灌点水平距离16个指标在内的风险评价指标体系。在此基础上,结合地下水使用功能,以20个典型再生水回灌场地调研结果和160种再生水回灌地下水污染风险因子物化特性为数据基础,对各指标进行了风险水平的划分,基于聚类分析法,采用各指标风险指数相乘的风险表征方法计算总风险指数,构建了再生水回灌地下水环境安全风险评价技术方法。该方法有效的避免了指标权重计算的主观性,并且能够直观的找出导致风险的主要因素。结果表明：利用建立的风险评价技术方法可将我国再生水回灌地下水环境安全风险划分为3级,风险值〈5为一级,风险值在5-15之间为二级,风险值〉15为三级。在某再生水回灌场地的应用表明,该回灌区地下水环境安全风险为二级,同时得出回灌水特征污染物特性指标是造成该回灌区地下水环境风险的主要因素。     

Nanomaterials for agriculture,food and environment: applications,toxicity and regulation

Nanotechnology is expected to have a beneficial influence on agriculture, food and environment, due to the unique properties of nanomaterials. However, little is known about their safety and potential toxicity. Here we review metal nanoparticles, nanometal oxides, carbon nanotubes, liposomes and dendrimers. We present the application of these nanomaterials in agriculture, food and environment for plant protection; disease treatment; packing materials; development of new tastes, textures and sensations; pathogen detection; and delivery systems. We discuss risk assessment of nanomaterials and toxicological impacts of nanomaterials on agriculture, food and environment. We then provide regulatory guidelines for the safer use of nanomaterials.     

A novel living agricultural concept in urban communities: Family Business Garden

During the process of urbanization, people are subject to the indiscriminate use of resources due to competition. The present trend in global population growth predicts that the situation will be aggravated as many people prefer living in towns and cities to resource-poor rural areas. In consequence, limited space, high percentage of ageing population, urban poverty, environmental pollution, changes in urban lifestyles and varied consumption patterns have to be dealt with in sustainable development strategies. In this context, urban agriculture can play a vital role by visualizing the urban homestead as a potentially viable production unit of agriculture. In order to live with limited urban infrastructure facilities, environmental conditions and socio-economic situations, the concept of the Family Business Garden justifies the necessity of its presence through the experience in the Western Province of Sri Lanka. Having a proper mix of environmental and commercial agricultural concerns, the concept paves the way not only to address family food requirements but also to produce for markets under liberalized economies by promoting agro-entrepreneurship and social capital development attempts in urban communities.     

Nanosensors for food quality and safety assessment

Food toxins are produced as defense tools by microorganisms that use nutrients for their growth. Microorganisms thus spoil food, taste and can infect humans, sometimes leading to death. Food adulteration and brand protection are also major issues in the food industry. Here we review the use of nanomaterials for sensing food quality. Nanosensors can detect pathogenic bacteria, food-contaminating toxins, adulterant, vitamins, dyes, fertilizers, pesticides, taste and smell. Food freshness can be monitored using time–temperature and oxygen indicators. Product authenticity and brand protection can be assessed using invisible nanobarcodes. Overall, nanosensors with unique properties are improving food security.     

基于高通量分析的长江干流重庆段重点关注污染物筛选

应用高通量分析方法对长江干流重庆段11个断面水体中的潜在污染物进行了分析,共筛查到230种污染物。结合重庆市化学品生产使用统计结果,应用综合评分法对潜在污染物进行了评分和排序,筛选出33种流域重点关注污染物,包括农药、工业用品(邻苯二甲酸酯类、酚类雌激素、有机溶剂)及个人护理品(抗氧化剂、合成麝香、紫外吸收剂)等。结果表明,基于高通量分析方法和综合评分法可成功识别和筛选流域内重点关注污染物,为流域管理提供科学依据。     

经济增长与农业碳排放关系的实证研究

研究首先基于农业投入与生产视角的6个主要方面碳源,测算了1993-2008年我国农业生产活动所导致的碳排放量,分析发现我国农业碳排放总量和强度分别年均增长率为4.08%、2.38%,但环比增速总体上处于阶段性下降态势。化肥、农药、农膜、农用柴油、灌溉、翻耕等导致碳排放年均递增率分别为3.45%、4.65%、7.20%、4.77%、1.22%、0.38%。进一步综合运用协整理论及误差修正模型,实证我国经济增长与农业碳排放之间的关系。结果表明：我国经济增长与农业碳排放总强度,以及经济增长与化肥、农药、农膜、农用柴油、翻耕等5类碳源导致的碳排放强度之间存在协整关系,且人均GDP每增加1%,农业碳排放总强度与化肥、农药、农膜、农用柴油、翻耕等碳源的碳排放强度分别增加1.72%、1.61%、1.18%、0.40%、2.48%和1.31%。最后,据此提出相关政策建议。