首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 326 毫秒
1.
The metaphor of the food system,dominant in current research approaches to sustainableagriculture, mirrors the productionist paradigm, whichreduces our relationship to land and food to theproduction and consumption of commodities. Theenactment of the familiar values of nourishment andhospitality is what the goal of sustainableagriculture would amount to in terms of our day to daylived experience. The metaphor of an earthen bowl asa theory of food and agriculture can embody thesevalues such that broader change might be achievedthrough embracing the idea and practice of theories asnourishing and theorizing as hospitable.  相似文献   

2.
In public debate over agricultural biotechnology, at issue hasbeen its self-proclaimed aim of further industrializingagriculture. Using languages of risk, critics and proponentshave engaged in an implicit ethics debate on the direction oftechnoscientific development. Critics have challenged thebiotechnological R&D agenda for attributing socio-agronomicproblems to genetic deficiencies, while perpetuating the hazardsof intensive monoculture. They diagnosed ominous links betweentechnological dependency and tangible harm from biotechnologyproducts.In response to scientific and public concerns, theEuropean Community enacted precautionary legislation for theintentional release of genetically modified organisms (GMOs). Inits implementation, choices for managing and investigatingbiotechnological risk involve an implicit environmental ethics.Yet the official policy language downplays the inherent valuejudgments, by portraying risk regulation as a matter ofobjective science.In parallel with safety regulation, thestate has devised an official bioethics that judges where todraw the line in applying biotechnological knowledge, as ifthe science itself were value-free. Bioethics may also judge howto balance risks and benefits, as if their definition were notan issue. This form of ethics serves to compensate for theunacknowledged value-choices and institutional commitmentsalready embedded in R&D priorities.Thus the state separatesrisk and ethics, while assigning both realms to specialists.The risk/ethics boundary encourages public deference to theexpert assessments of both safety regulators and professionalethicists. Biotechnology embodies a contentious model of controlover nature and society, yet this issue becomes displaced andfragmented into various administrative controls. At stake arethe prospects for democratizing the problem-definitions thatguide R&D priorities.  相似文献   

3.
The widespread trend to transferirrigation management responsibility from the stateto communities or local user groups has byand large ignored the implications ofintra-community power differences for theeffectiveness and equity of water management. Genderis a recurrent source of such differences. Despitethe rhetoric on womens participation, a review ofevidence from South Asia shows that femaleparticipation is minimal in water usersorganizations. One reason for this is that theformal and informal membership criteria excludewomen. Moreover, the balance between costs andbenefits of participation is often negative forwomen because complying with the rules and practicesof the organization involves considerable time costsand social risks, whereas other ways to obtainirrigation services may be more effective for femalewater users. Although effective, these other andoften informal ways of obtaining irrigation servicesare also typically less secure. More formalparticipation of women can strengthen womensbargaining position as resource users withinhouseholds and communities. Greater involvement ofwomen can also strengthen the effectiveness of theorganization by improving womens compliance withrules and maintenance contributions. Furtherdetailed and comparative research is required toidentify the major factors that affect womensparticipation and control over resources, ifdevolution policies are to address the tensionbetween objectives of transferring control overresources to community institutions, and ensuringthe participation of all members of the community,especially women.  相似文献   

4.
Rural women did not fare very well inthe land reforms carried out during the Latin Americanreformist period of the 1960s and 1970s, with womenbeing under-represented among the beneficiaries. It isargued that women have been excluded from access toand control over water for similar reasons that theywere excluded from access to land during thesereforms. The paper also investigates the extent towhich women have gained or lost access to land duringthe counter-reforms of the 1980s and 1990s. Underthe neo-liberal agenda, production cooperatives aswell as communal access to land have largely beenundermined in favor of privatization and theindividual parcelization of collectives. Significantland titling efforts are also being carried outthroughout the region to promote the development of avigorous land market. This latter period has also beencharacterized by the growth of the feminist movementthroughout Latin America and a growing commitment bystates to gender equity. The paper reviews the extentto which rural womens access to land and, thus, waterhas potentially been enhanced by recent changes inagrarian and legal codes.  相似文献   

5.
This study explored local controls relating to trees and spacesof the local environment in Nyamaropa Communal Lands in theNyanga District of eastern Zimbabwe. Controls were consideredin a broad and inclusive framework encompassing codified rules,taboos, and, regulatory norms and emotions. Special emphasis waslaid on peoples emotional and ethical investment in the abovecomponents of the environment – trees and spaces. The studyemployed intensive informal and group interviews. Results showthat there is tremendous emotional and ethical investment intrees and spaces of the environment in Nyamaropa. Emotions comein a variety of forms: fear, shunning, love, reverence, andconfidence and security enhancement. The emotional and ethicalnorms are designed to govern behavior and the context of resourceutilization. These norms have implications on the organization ofspaces of the local environment and regimes of resource utilizationoccurring in them. Location of resources in spaces of the environmenthas implications on the management of resources within them. Thedomains of human habitation – home bases and home fields – werefound to be the most emotionally laden spaces with trees in thembeing actively planted, nurtured, conserved, eliminated, or destroyedon the basis of certain emotions and norms. The findings of the studyhave implications within the framework of decentralization and ofdemocratization of natural resource management.  相似文献   

6.
Shi  Z.  Wang  K.  Bailey  J. S.  Jordan  C.  Higgins  A. J. 《Precision Agriculture》2000,2(4):347-357
Unlike the situation for arable soils, virtually nothing is known about the spatial dependencies of soil properties in cool temperate grassland or about what the optimal sampling strategies ought to be for mapping soil nutrient distributions in such situations. The aim of this study was to investigate the spatial variability in plant-available (soil) phosphorus and potassium in a grass silage field in Northern Ireland and devise optimal sampling strategies for mapping their distributions. Soil samples were collected from the field at 25 m intervals in a regular rectangular grid to provide a database of soil properties. Different data combinations were subsequently abstracted from this database for comparison purposes, and ordinary kriging used to produce interpolated soil maps. Soil potassium displayed greater spatial variability than soil phosphorus. In keeping with this observation, the results of three separate statistical procedures demonstrated that the optimal sample size for estimating the true population means was about twice as large for soil potassium as for soil phosphorus. Optimal sampling strategies, however, related not just to sample size but to sample combination and field shape as well.  相似文献   

7.
Precision Agriculture requires a method of gathering information about the spatial variability of soil that reduces the need for expensive and intensive sampling. This can be achieved through the use of what we term average and proportional variograms. A literature search has enabled the gathering of variograms for multiple soil properties, allowing comparison of the magnitude of variability and the construction of averages. For soil properties that display proportionality between their mean squared and variance, the variogram can be predicted from a mean value. These average and proportional variograms are potentially beneficial to implementers of Precision Agriculture as they can be used to plan optimal soil sampling and management schemes. It was found that if wishing to implement site-specific management to a resolution of 20×20 m then grid soil sampling will generally have to be performed at 20–30 m intervals depending on the attribute of interest. A decision-support chart for differential soil management based on a variogram's comparative magnitude to the average is presented. Further work needs to be done on increasing the data base these results are based on and refining the proportional variogram parameters to site-specificity.  相似文献   

8.
An examination of the role ofUniversity weed scientists in herbicide efficacyresearch and long-term weed management studies raisesseveral important questions: who should do what kindof research and what kind of research should be done,and, because the university is a research institutionfunded by the public, there is also the importantquestion of who should pay for the research. Indeveloping a response to these questions, severaldimensions of the relationships within which weedscience works must be considered. The authorsexperience has demonstrated that production, thedominant value in agriculture, provides a sufficientanswer to the questions for many in weed science.However, when weed scientists claim credit forexcellence in production they must also acceptsocietys right to hold them responsible for problemsthey now treat as externalities.  相似文献   

9.
In the absence of suitable technology to measure and map the dry matter (DM) yield distributions of forage grass crops within individual fields, a manual procedure of yield mapping has been developed. Samples of herbage are collected just prior to each silage harvest from known grid points within a field, and sward DM yields at each point are predicted from the mineral composition of the herbage, using empirical mathematical models. Yield maps (and maps of sward nutrient status) are then produced by kriging interpolation between the point data. To make the most efficient use of time and resources, however, sampling intensity needs to be kept to the absolute minimum necessary for interpolation purposes. The aim of the present study was to examine the spatial variability in sward DM yield and mineral nutrient status in a large grass silage field under a three-cut system, and devise optimal sampling strategies for mapping the distributions of these parameters at each cut. Herbage samples were collected from the field, prior to each harvest, at 25 m intervals in a regular rectangular grid to provide databases of herbage nutrient contents and DM yields. Different data combinations were abstracted from these databases for comparison purposes, and ordinary kriging used to produce interpolated maps of DM yield and sward N, P, K and S statuses. The results suggested that a sampling density of just seven samples per hectare was adequate for estimating the true population means of sward DM yield and sward N, P, K, and S statuses. For mapping purposes, it was found that the best compromise between interpolation accuracy and sampling efficiency was to collect herbage samples in a 35.4 m×35.4 m equilateral triangular sampling pattern.  相似文献   

10.
In this paper I propose a series of hypotheses for further study that are related to potential negative impacts of non-traditional export agriculture (NTEA) on peasantfarmers in Central America. International lenders and donor agencies are promoting this diversification of agricultural exports as part of structural adjustment programs in the region, in order to increase foreign exchange earnings and raise the incomes of the rural poor.There is growing evidence, however, that the impact on the rural poor may not be favorable. I argue that because NTEA can introduce powerful economies of scale, it is likely to accelerate social differentiation in the countryside and expel large numbers of peasant farmers from their lands. In this sense NTEA may be similar to previous export booms, leading to rapid intensification of social instability and conflict in an already troubled region. This raises the serious question of the long term sustainability of this development strategy.  相似文献   

11.
12.
The Fair Trade movement seeks to alter conventional trade relations through a system of social and environmental standards, certification, and labels designed to help shorten the social distance between consumers in the North and producers in the South. The strategy is based on working both in and against the same global capitalist market that it hopes to alter, raising questions about if and how Fair Trade initiatives exhibit counter-hegemonic potential to transform the conventional agro-food system. This paper considers the multiple levels at which Fair Trade alternatives operate to identify the different forms of social action that the movement engages with, and to clarify where the movements counter-hegemonic potentials are being realized. I suggest the Fair Trade movement is most successful in encouraging consumers and producers to commit acts of resistance and in supporting redistributive action that shifts resources from North to South. Up to now, however, Fair Trade alternatives appear to hold only a theoretical potential to provoke transformative change in the agro-food system. A reconceptualization of the Fair Trade model and how it is implemented could allow it to manifest more of its implicit, oppositional promise.Aimee Shreckis a sociologist and the Research Specialist for the California Faculty Association. Her previous work as a postdoctoral researcher with the University of California, Berkeley and the Sustainable Agriculture Research and Education Program focused on social justice, sustainable agriculture, and fair trade.  相似文献   

13.
Michigan's approach to sustainability does not conflict with its efforts to reindustrialize state agriculture. As currently applied, agricultural sustainability remains a one-dimensional concept tightly focused on the condition of production resources and the larger physical environment. The social and political dimensions of sustainability, by contrast, are conspicuously absent. Using Michigan's livestock initiative as a case in point, it is argued that this conceptualization conforms to and reinforces the reindustrialization of agriculture and the existing structure of power within the industry.Laura B. DeLind is a Specialist in the Department of Anthropology at Michigan State University, East Lansing, Michigan. Her current research focuses on the economic and political structure of Michigan agriculture. She has written numerous articles critically evaluating the effects of state agricultural programs and policies at the local or community level.  相似文献   

14.
15.
Nitrogen (N) emissions to ground and surface waters have become a major concern in many regions. In reaction, policy makers are tightening environmental constraints on agriculture, resulting in a call for more efficient management systems. This study presents a methodology for precision N fertilization in high-input farming systems applying split fertilizer strategies. Essentially, the method uses a mechanistic simulation model to quantify (i) soil mineral-N levels and (ii) N uptake rates on a real-time basis. Early warning signals are generated once N concentrations drop below a critical threshold level, indicating that additional fertilizer should be applied. Thresholds are not static, but defined in relation to actual uptake rates. Spatial variation is incorporated through the concept of management units: i.e., stable units with relatively homogeneous characteristics in terms of water regimes and nutrient dynamics. Separate simulations are conducted for each management unit, based on selected representative soil profiles. The proposed methodology was tested in a winter wheat (Triticum aestivum L.) field during the 1998 growing season. Six experimental strips were delineated receiving either precise or traditional fertilization. Precision fertilization proved efficient in reducing fertilizer inputs (–23%), while slightly improving grain yields (+3%) and hectoliter weights (+4%). Results clearly illustrate the significance of precision management in the process of increasing fertilizer use efficiency.  相似文献   

16.
17.
The movement towards precision agriculture has led to calls for soil maps that are more detailed and accurate than those offered in standard NCSS soil surveys. Studies have shown that soil variability can be greater than depicted in soil surveys; in fact, delineations that contain at least 50% of the soil mapped are considered satisfactory for soil survey purposes. Lacustrine plains are relatively flat and often have parent materials with uniform properties. Because soils are usually mapped using soil–landform relationships one might expect soil maps in these areas to be less accurate than average; it is difficult to delineate between map units using soil–landform relationships in such subtle landscapes. We grid-mapped a field containing lacustrine-derived soils in central Iowa and used the grid to evaluate the soil survey for accuracy. Two major and two minor soils, as determined by the area they occupy in the field, were present. For the field as a whole, the two major soils were correctly identified by the soil survey at least 63% of the time. The two minor soils were correctly identified 33% of the time or less by the soil survey. Large-scale soil mapping is expensive because of the time involved to create them in the field and in the office. Therefore, it is only economically beneficial to produce a detailed map if the map leads to significant alterations in the way a field is managed. In fields that may have uniform soil properties, it may be more cost-effective to conduct a reconnaissance survey first and then decide if more detailed mapping is required.  相似文献   

18.
农村承包经营土地“三权分置”改革,进一步为农地经营权抵押贷款提供了法律支持和制度 保障。农村土地经营权抵押贷款,为盘活农村土地这一“沉睡资产”,促进“三农”发展提供了有力的资 金支持,从而带来了巨大的社会经济效益。农村土地经营权抵押贷款有助于农民脱贫增收,有助于农 村振兴,有利于推动农业的现代化。但事物的两面性决定了农村土地经营权抵押贷款在带来效益的 同时也会带来社会成本,农业环境效率、贫富差距、社会公平和社会稳定等问题需要给予重视。  相似文献   

19.
干旱区内陆河流域典型灌区土地利用变化与耗水量研究   总被引:2,自引:0,他引:2  
【目的】以阿克苏河灌区为例,研究干旱区内陆河流域土地利用变化与耗水量的关系,为干旱区土地资源开发与保护提供科学依据。【方法】基于2000~2014年TM遥感影像,运用GIS技术和土地利用模型,结合灌溉用水量和土壤含水量的变化趋势,分析近15 a阿克苏河灌区土地利用/覆被变化现状以及耕地扩张与灌区耗水量的关系。【结果】阿克苏河灌区土地利用变化明显,灌区耕地面积以159.8 km2/年的速度增加,以塔河灌区耕地增加最为明显;随着灌区耕地面积的急剧增加,灌区内耗水量加大;灌区内土壤含水量减少,平原荒漠区的一些浅根系荒漠植物因干旱胁迫死亡,中、低覆盖草地面积大幅下降,灌区外围荒漠化风险加大。【结论】在全球变暖背景下,耕地面积的不断扩大,是导致灌区耗水量增加的主要原因。  相似文献   

20.
我国灌溉农业的现状与发展趋势   总被引:5,自引:0,他引:5  
我国现有有效灌溉面积约占全国耕地面积的50% 左右,却生产全国80% 的粮食。但我国的水资源相对缺乏,农业用水供需不平衡,浪费严重,灌溉农业面临困境。我国的农田灌溉区存在诸多问题,解决和缓解水资源危机的有效途径是开源与节流并举,节水灌溉技术是今后灌溉农业发展的主流。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号