Soil management practices for sustainable agro-ecosystems

A doubling of the global food demand projected for the next 50 years poses a huge challenge for the sustainability of both food production and global and local environments. Today’s agricultural technologies may be increasing productivity to meet world food demand, but they may also be threatening agricultural ecosystems. For the global environment, agricultural systems provide both sources and sinks of greenhouse gases (GHGs), which include carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). This paper addresses the importance of soil organic carbon (SOC) for agro-ecosystems and GHG uptake and emission in agriculture, especially SOC changes associated with soil management. Soil management strategies have great potential to contribute to carbon sequestration, since the carbon sink capacity of the world’s agricultural and degraded soil is 50–66% of the historic carbon loss of 42–72 Pg (1 Pg=10¹⁵ g), although the actual carbon storage in cultivated soil may be smaller if climate changes lead to increasing mineralization. The importance of SOC in agricultural soil is, however, not controversial, as SOC helps to sustain soil fertility and conserve soil and water quality, and organic carbon compounds play a variety of roles in the nutrient, water, and biological cycles. No-tillage practices, cover crop management, and manure application are recommended to enhance SOC storage and to contribute to sustainable food production, which also improves soil quality. SOC sequestration could be increased at the expense of increasing the amount of non-CO₂ GHG emissions; however, soil testing, synchronized fertilization techniques, and optimum water control for flooding paddy fields, among other things, can reduce these emissions. Since increasing SOC may also be able to mitigate some local environmental problems, it will be necessary to have integrated soil management practices that are compatible with increasing SOM management and controlling soil residual nutrients. Cover crops would be a critical tool for sustainable soil management because they can scavenge soil residual nitrogen and their ecological functions can be utilized to establish an optimal nitrogen cycle. In addition to developing soil management strategies for sustainable agro-ecosystems, some political and social approaches will be needed, based on a common understanding that soil and agro-ecosystems are essential for a sustainable society.     

Are the parasiticidal avermectins resistant to dissipation in the environment? The case of eprinomectin

Eprinomectin (EPM) is a veterinary drug currently licensed in many countries for the treatment of endo- and ecto-parasites in cattle. Despite the notable evidence for its high toxicity to the terrestrial and aquatic environment ecosystems, its environmental behavior and fate are currently unknown. In the present research, the dissipation of EPM was studied in three soils and in cattle manure by using the OECD 307 guideline and the recently developed European Medicines Agency (EMA/CVMP/ERA/430327) guideline, respectively. The procedure presented by the FOrum for Co-ordination of pesticide models and their USe (FOCUS) was adopted for estimating the EPM degradation kinetics in soil and cattle manure. The EPM dissipation in soil was best described by the SFO (Simple First Order) and the HS (Hockey Stick) models, under aerobic and anaerobic conditions, respectively. The EPM dissipation in cattle manure was best described by the FOMC (First Order Multi Compartment) model. The Dissipation Time for the 50% of the initial EPM mass (DT₅₀) range was 38–53 days under aerobic and 691–1491 days under anaerobic conditions. In addition, the DT₅₀ for EPM in cattle manure was 333 days. Therefore, EPM could be characterized as moderately to highly persistent to dissipation in soil, which depends on soil type, its oxygen content (aerobic or anaerobic conditions in soil) and the microbial activity. Moreover, the EPM resists dissipation in cattle manure, resulting to a high load in soil after manure application in agricultural land (or direct defecation in grassland). Consequently, the high possibility for EPM accumulation in soil and cattle manure should be considered when assessing the environmental risk of the drug.     

Soil erosion tolerance and water runoff control: minimum environmental standards

Council Regulations (EC) No 1257/1999 and the EU Soil Thematic Strategy give great importance to soil and land conservation to develop knowledge driven governance for rural development. In the hilly areas of Italy cultivated intensively, and especially in the ones devoted to viticulture, agricultural practices determine high loss of soil with consequent degradation of the soil resource. In addition to it, offsite effects of soil erosion can be unsustainable, due to sediment transfer to the channel network and infrastructures. In order to achieve a sustainable rural development there is a need for tools and instruments to allow European regional administrations, to develop, implement, manage and monitor rural development plans. To counteract the environmental threats intensified by agricultural activity, the environmental functions “soil erosion control” and “water runoff control” were investigated in the Chianti area by using GIS. To determine the EMR (Environmental Minimum Requirements) values for soil erosion the “regeneration” capability of soils was considered, and the value of estimated soil loss was compared with the value of soil reformation. A scenario analysis was also performed to evaluate the effectiveness of the agroenvironmental measure “grass cover” in reducing erosion. The concept of tolerable erosion based on soil productivity and soil reformation rate only is reductive and off-site effects of soil erosion should be also taken into account. For this reason, it was proposed to extend the concept of hydrogeological risk to soil erosion by implementing the notion of soil erosion tolerance (T) with the new concept of environmental risk of soil erosion (ERSE). The new ERSE index takes into account all the in- and off-farm externalities of soil erosion. For this reason, it can be considered an aggregated environmental indicator that enables policy makers to evaluate the impacts of soil erosion by following an holistic approach.     

Linking perceived land and water resources degradation,scarcity and livelihood conflicts in southwestern Tanzania: implications for sustainable rural livelihood

In Africa, the land and water resources quality are key factors for sustainable development. The degradation of the quality of these resources leads to scarcities and conflicts, which together threaten the sustainability of rural livelihoods. This work investigated and analysed the livelihoods conflicts over the land and water resources and their scarcities, policies that contributed to the land and water scarcities and the livelihood conflicts and linkage of the conflicts to the resources scarcities and degradation. Implications of degradation of the resources, development policies and livelihoods conflicts on sustainable development are discussed. Literature study, visits and discussions, participatory assessments, observations and questionnaire survey were used tools to collect data. Interviews of the 266 households revealed that, those experiencing the land and water scarcities and conflicts over these resources are significantly (p < 0.001) higher than those not experiencing the scarcities and conflicts. Crop-livestock competition, over the land and water resources causes prominent conflicts. A significant, (p < 0.05) associations of livelihoods conflicts to water shortage and period of water shortage for crop and livestock production were found. Improved accessibility to soil and water management technologies, wildlife–livestock co-existence, recognition of needs and land rights for pastoralists are recommended to minimize scarcities and herders versus farmers’ conflicts.     

Population dynamics,rural livelihoods and environmental degradation: some experiences from Tanzania

Population growth and environmental degradation are closely linked. Increasing population has in many rural areas of Tanzania contributed to changes in land use/cover patterns, land fragmentation and livelihood insecurity. Increasing demand for food, energy and other environmental services has contributed to expansion of agriculture, including marginal areas, and deforestation often leading to environmental degradation. Increased reliance on natural resources for rural livelihoods, subsistence nature of the agricultural sector and limited economic opportunities in rural areas are among the factors leading to rural–rural and rural–urban migrations searching for better livelihood opportunities. The high urban demand for food and biomass energy from rural areas has also contributed to rural deforestation and overall environmental degradation. This paper addresses the linkages between population and environmental degradation in Tanzania. It argues that effective implementation of development and resources management policies can lead to environmental sustainability even with growing populations. It provides evidence from successful land management interventions such as HADO, HASHI and SECAP, which support the argument that with effective implementation of resource management initiatives even larger populations can be supported by the available resources. Such successful interventions ought to be emulated elsewhere with similar environmental problems.     

WSSD 2002, Latin America and Brazil: Biodiversity and Indigenous People

Latin America comprehends notable variations in terms of natural environment, availability of natural resources, living standards, and demographic patterns. Latin America is a mosaic of cultures, post- and pre-Columbian. The rich variety of life forms discovered and described by chroniclers and traveling naturalists in the Neotropics contributed to the proposal, in mid-XVIIIth century, of a new system of classification and a scientific code of nomenclature for all organisms. Biodiversity was, for many centuries, a source of resources to be exploited in natura. In scientific circles, its inventory became the domain of taxonomists. But modern technology showed how important the miriad of life forms really are as sources of chemical molecules to be engineered as drugs and reassembled as novel manufactured products. We are on the brink of a new agricultural and medical revolution, thanks to the techniques of genetic engineering, which will lead eventually to the elimination of hunger and malnutrition.In this essay, the Brazilian environmental and social heterogeneity will serve as an example to illustrate some key points, which have influenced sustainability policies. The Amazon deforestation and indigenous knowledge (IK), subjects often associated with areas of high biodiversity, are usually the focus of environmental debates. The importance of IK in integrating development, reducing poverty and sustainability are considered together with the intellectual property rights of native populations.In the World Summit on Sustainable Development (WSSD) Implementation Plan, a few paragraphs were dedicated to Latin America, because of the pre-existing Action Platform on the Road to Johannesburg 2002, approved in Rio de Janeiro in October 2001. This paper calls attention to the need to draw up specific environmental policies for a region which shows an extremely high cultural and biological diversity, associated with a high availability of forests and water, among other resources.     

Agricultural land use efficiency and food crop production in Ghana

Despite the low productivity of the extensive agriculture system, Ghana recorded the largest reduction of undernourishment in the past two decades. We used biophysical analysis to determine the efficiency and potentials of the extensive system and its future sustainability. The results indicate that food production in Ghana has increased steadily over the past two decades and correlated highly with cropped area and population (R ² < 0.85 and 0.82), but not with fertilizer (R ² = 0.06). Sufficient food production could be sustained in the short term. In the longer term, however, the food situation in Ghana appears precarious if population growth continues while land remains the same.     

实现林业可持续发展的财政政策取向

林业的可持续发展，既体现了林业生产力发展水平和生态文明社会，又承载着满足社会日益增长的多样化需求，在人与自然和谐发展以及建设环境友好型社会中居于十分重要地位。分类经营是实现林业可持续发展的重要途径。国家应当制定以公共财政为主全社会多渠道投入支持林业建设的财政政策。     

我国粮食安全保障中改善农业环境的途径

本文分析了我国粮食安全及粮食持续生产所依托的农业环境状况。从我国粮食生产状况与经济发展水平看,全国粮食生产处于结构性过剩与低水平安全中,区域性粮食安全与不安全并存;耕地资源、水资源以及农民的经济收入状况等均不容乐观,加之自然灾害加重,粮食生产的环境成本将随之增加,这将影响我国未来粮食安全。为此,本文提出了走农业集约化道路是解决我国粮食安全与改善环境的基本途径。     

鲁西北地区农户家庭农地规模经营行为分析

本文根据1986-2001年鲁西北地区农村固定观察点陵县和阳谷县2个村共80户（1993年以前为120户、115户或141户）跟踪观察资料，对鲁西北地区农户经济活动行为及不同规律农户分布、农户家庭纯收入水平、农地生产率等加以分析，研究结果和结论可为区域农业和农村经济可持续发展有关政策的制定提供科学依据。     

乡镇工业企业发展与环境,资源协调问题初探

我国乡镇工业企业的发展与环境、资源的协调问题已经成为我国发展与环境、资源关系方面的大问题。实行工农相对分离,组建乡村工业区,是提高乡镇工业企业素质、效益,强化乡镇工业企业优化组合、规模经营的有效途径;是保护环境,实现资源有效利用的基础工作之一;是提高农业劳动生产率,实现农业规模经营的基础工作之一。     

Community-based natural resources management (CBNRM) in Xinhui, Guangdong Province, China

Using institutional appraisal focused groups (FG) and participatory appraisals with Dillman Total Design Method (TDM), this study examines community interaction with and utilization of wetland resources in Xinhui, Guangdong Province, China. Field results show high commercial activities and corresponding impacts on coastal environment. Other interacting factors identified include: legislation and ecosystem management, stakeholders’ participation, international guidelines criteria, and utilization of mangrove resources in the region. Sensitivity index and community-based natural resources management collaboration comparison percentile showed significant differences between cumulative distributions of respondents (D = 0.2568, P = 0.078). Likert statement of 11 sensitivity optional indexes in EMS of K–S test at 0.05 level of P = 0.078 also show significant differences in interaction between respondent groups and sensitivity factors. This indicates a dysfunction between regional environmental management systems and CBNRM in Xinhui coastal district. Considering the high tourism potential and economic quest of the region, there is the need for coordinated community enlightenment and further studies on the social, ecological and economic value of wetland resources. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

绿洲农区土地可持续利用初步研究——以河西走廊临泽样区为例

土地可持续利用就是实现土地生产力的持续增长和稳定性 ,保证土地资源潜力和防止土地退化 ,并具有良好的社会效益和经济效益。本文以河西走廊临泽样区为例 ,以根据土系划分出的三种土地利用方式为研究对象 ,对其在土地可持续利用方面进行了定量化评价研究 ,在此基础上 ,提出了绿洲农区土地可持续利用途径     

Influencing factors on sustainable development: a case study in Quang Tri province,Vietnam

Background Sustainable development (SD) is a common concept. Knowledge and attitudes are essential in the SD process. This study assesses the knowledge, attitudes, and practices (KAP) of local people about SD. Aim To study the factors that influence the understanding of the concept, contents, and indicators of different aspects affecting the health and environmental issues. Methods A cross-sectional study was carried out from June to July 2007 among 546 households in the Quang Tri province. Data were gathered on basis of socio-demographic variables, namely age, gender, education, occupation, income, and region. Chi square tests and multivariate analysis were performed on the obtained data. The data were cleaned and analysed using SPSS 15.0 for windows. Results Occupation is related to knowledge, attitude, or practice. Income is related to knowledge or practice. Gender related to only attitude. Lastly, region is related to attitude or practice. The proportion of wrong understanding about SD is 2.0 times (95% CI: 1.3; 3.1, p < 0.001) higher than that of the people who have good understanding about it. The rate of willingness to do any related SD programmes of the people who understanding is 2.1 times (95% CI: 1.4; 3.2, p < 0.001) higher than that of the people who have bad one. Conclusions This study shows that knowledge on sustainability of the local communities is low. Occupation and income influence understanding of SD more than region, age, gender, and education. Most of the local people who do not understand SD in general, do not want to participate or act in SD programmes.     

Controlling non-point-source pollution by rural resource recycling. Nitrogen runoff in Tai Lake valley, China, as an example

Agricultural non-point-source (NPS) pollution is regarded as the dominant contributor to water quality degradation and eutrophication in China. Nitrogen (N) is a primary source of pollution in fresh water bodies. In this work a linear programming model was developed to simulate the effectiveness of different nitrogen runoff control policies, using Pinghu City in Tai Lake valley as an example. Four policy scenarios were tested: a tax at a rate equivalent to 50% of the cost of nitrogen fertilizer (S1); a ban on summer fertilizer applications to make the most use of fertilizer applied in the spring (S2); mandatory substitution of regular fertilizers by controlled-release fertilizers (S3); and a subsidy of US$300 ha⁻¹ (RMB￥150 mu⁻¹) for using compost (S4). The results indicate that all four policies would effectively reduce nitrogen runoff—by 9.8, 26.8, 14.4, and 80.0%, respectively. A subsidy for recycling domestic animal manure and utilizing compost had the most significant effect on the reduction of nitrogen runoff without reducing household income. This research suggests that measures to control agricultural NPS pollution should be combined with a policy to promote recycling of bio-resources and that financial support for NPS pollution control combined with bio-resource recycling should be regarded as one aspect of public investment in regional sustainable development.     

Sustainable Agriculture in the UK

Most agricultural assessments of global environmental change made to date have not focused explicitly on sustainability issues, and have neglected the considerable impacts of shifting agricultural zones, alterations in commercial fertiliser and pesticide use, and changes in the demand for water resources. The current crisis in agriculture, with its economic, political, social and ecological dimensions, has arisen because of the pursuit of a productivity technology/policy model. This broad policy of agricultural ‘modernisation’ and development through the application of agricultural science and technology has shaped the direction of technological change in agriculture and the evolution of a complex agro-industrial food system.¹ This paper focuses on England’s Rural Development Programme² as it contributes to sustainable agriculture alongside the control of pollution.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

我国发展循环经济的政策与法律体系探讨

建立和完善循环经济政策应遵循三个原则：服务于我国循环经济概念与内涵原则。服务于循环经济实践的原则。用足用好现有政策和补充缺位政策相结合的原则。我国发展循环经济的政策与法律体系应包括四大类：基本政策、核心政策和基础性政策。技术政策可以融入这四类政策之中。基本政策是统领循环经济所有政策的根本。是资源环境与社会经济发展相融合的综合性政策。基础性政策是指为循环经济重点领域实践创造良好制度环境的政策。大致包括宏观经济政策、基本经济制度、基础性激励政策和考核政策等。核心政策是直接推动循环经济重点实践领域的政策。在核心政策中。需要切实落实和用足用好的现有对循环经济发展较有利的政策有：生态工业政策（包括产业结构调整政策、清洁生产政策）。资源综合利用和环保产业税费优惠政策。能源节约和再生能源政策。环境友好型产品标志（标识）政策；需要完善的薄弱政策有：生态工业园建设政策。废弃物回收、再利用、资源化和无害化产业政策。生态农业政策。资源开发利用政策；需要新建立的缺位政策主要涉及消费领域、环境友好型和资源能源节约型城镇基础设施和建筑领域。     

Urbanisation Without Development: Environmental and Health Implications in African Cities

Sustainable development advocates for a balance between socio-economic development and the environment in the pursuit of human advancement. In Africa, high population growth and inadequate infrastructure in urban areas exert pressure on the environment and this threatens the health and wellbeing of urban residents. The population of the African continent until the 1960s was predominantly rural. This scenario has taken a swift turn and some of the major shifts in the global urbanisation process are taking place on the continent. Factors including natural increase in the population, rural–urban migration, strife and hunger leading to the internal displacement of populations have exacerbated the urbanisation process in Africa. The situation has been worsened by the imposition of Western development policies, including structural adjustment programmes on African nations, which has eroded the subsistence base of rural agricultural communities and further ignited rural urban migration. The failure of industry to absorb the increasing labour force has created massive unemployment and deepening poverty crisis in urban centres. Inadequate provision of infrastructure and services to meet the growth in urban populations has resulted in inefficient spatial development of urban centres, the proliferation of squatter settlements, inadequate basic amenities including potable water, sanitation and waste disposal. Poor environmental sanitation has resulted in the upsurge of infectious diseases and deteriorating urban health. Urban populations in Africa are also the worst affected by newly emerging diseases, particularly HIV/AIDS. The poor bear a disproportionately large share of the problems due to their particular vulnerability to environmental and health risks. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

建设资源节约型农业的途径与模式

建设资源节约型农业的根本途径是提高农业生产力。其中主要的措施有:科学利用气候资源,充分发挥气候生产潜力;十分珍惜每寸土地,努力提高土地生产率;大力推行节水措施,扩大农田灌溉面积;科学合理施肥,持续提高单产;提高能源利用率,解决农村能源短缺;实现人畜分粮,缓解人地关系;促进农产品商品流通,提高农业经济效益等。立体农业是发展资源节约型农业的最佳模式,也是中国式的高效益资源节约型农业的重要模式之一。     

Environmental externalities in relation to agricultural sector in Thailand with trade-linked analysis

Thailand plays an important role in the international trade of food and agricultural products, which is in alignment with its national strategy of serving as the “kitchen of the world.” When looking at its agricultural promotion and export policies, the country only counts the value gains from exports while neglecting environmental externalities related to plantation practices. The purpose of this study was to perform a trade-off analysis between consumptive water, land, and fertilizer use together with the economic values of major crops for export and consumption in the country. The results show that to gain income from agricultural exports, the country has exploited various natural resources. The area used to harvest rice, sugarcane, cassava, and rubber adds up to approximately 15.3 million ha: 7.2 million ha of which is for domestic consumption and 8.1 ha for export. To produce Thailand’s agricultural exports, total water use is estimated to be 49.8–67.5 billion m³ per year (61–65 %), while the amount used to produce crops for domestic consumption is 26.5–43.7 billion m³ per year (35–39 %). Meanwhile, 1,056–1,826 thousand tons (54 %) of fertilizer was used on crops for domestic consumption, and 1,222–1,370 thousand tons (46 %) of fertilizer was used on export crops. The best crop choice for export in terms of its export value, land use, fertilizer use, and water consumption is rubber. The worst crop choices for export are rice and cassava. More sustainable agricultural practices are needed to effect improvements such as increased yields and reduced fertilizer and water use.