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1.
Agriculture, pesticides and the ecosystem   总被引:1,自引:0,他引:1  
Economists have a good understanding of intra-economic interdependence and a mature methodology of modelling it. Ecologists focus on the complex and sensitive interactions of species in ecosystems. This paper’s objective is to suggest a new micro-foundation of ecosystem analysis based on economic methodology, to integrate the analyses of the ecosystem and the economy and focus on the interface of ecosystem-economy relations. Agriculture forms a major part of this interface. The basic assumption is that in the short run the individual organisms of all species behave as if they optimise their costly offensive and defensive activities given other organisms’ activities (Nash-behaviour).We consider an ecosystem with three species in a unidirectional food chain: buzzards feed on mice, mice feed on grain, and grain feeds on solar energy. A fourth species, humans, also feeds on grain. Humans intervene in the ecosystem in various ways. They can grow grain by using seed, farm labour, pesticides and possibly nature conservation measures to maintain buzzard habitat. Short-run ecosystem equilibrium is characterised, and it is shown, in particular, how this equilibrium depends on farming activities. We then link this ecosystem model to a simple model of an agricultural economy. Both systems are solved for equilibrium simultaneously. From an economic perspective the ecosystem induces positive and negative externalities in agricultural production and in consumer ‘green’ preferences.The inefficiencies of the competitive economy are identified and some possibilities to restore efficiency through corrective taxes or subsidies are briefly discussed. We also outline how short-run equilibria are connected through ecosystem stock-flow relationships. Due to the complexity of the inter-temporal analysis, the resulting ecosystem dynamics cannot be characterised in general analytical terms. It is a topic for future research to study the dynamics in numerical analysis to understand under which conditions the joint ecological and economic system is driven toward a (sustainable) steady state.  相似文献   

2.
[目的]粮食问题关系国家安全、政治稳定和社会安定,是实施乡村振兴战略的首要任务。深入剖析新时期下农户粮食生产的影响因素,是保证国家粮食安全的现实要求。[方法]文章基于农户实地调研数据,运用工具变量法和样本选择修正模型分析农业机械化水平对农户主粮生产的影响。[结果](1)农业机械化水平对农户主粮生产有显著的正向影响,农业机械化水平每提高1%,农户主粮单产就提高1.219%,其中,水稻单产增加1.220 7%,小麦单产增加0.807 6%,玉米单产增加1.106 4%,马铃薯单产增加1.3798%。(2)从控制变量来看,户主受教育年限、户主务农经验、粮食补贴、农药化肥投入和平原地形都对不同主粮作物生产有积极作用,家庭外出务工占比、土地流转和气候极端变化都对不同主粮作物生产有消极作用。[结论]在农户不大幅调整当前主粮种植结构的前提下,适当增加马铃薯种植面积,提高种粮农户农业机械补贴力度,推广农机社会化作业服务模式,从而提高粮食产量,保障国家粮食安全。  相似文献   

3.
Can radical political‐economic transformation be achieved by electoral regimes that have not thoroughly reconstructed the state? Contemporary Venezuela offers an optimal venue for examining this question. The Chavista movement did not replace the previous state: instead, its leaders attempted to reform existing state entities and establish new ones in pursuit of its transformation agenda. It has also used its oil wealth to support cooperatively‐oriented economic activity, without necessarily fundamentally altering the property structure. Thus, the social change‐oriented political economy exists alongside the traditional one. Focusing on agrarian transformation, we examine ethnographically how these factors have impacted the state's capacity to attain its goal of national food sovereignty. We find that the state's ability to accomplish this objective has been compromised by lack of agency‐level capacity, inter‐agency conflict and the persistence of the previously‐extant agrarian property structure. These dynamics have influenced the state to shift from its initial objective of food sovereignty to a policy of nationalist food security.  相似文献   

4.
[目的]长期以来,粮食生产与生态保护一直是一对矛盾综合体,为了实现粮食安全目标,人们往往忽略对于生态的保护,通过对二者之间的相互影响机理的分析,提出更好的宏观调控政策。[方法]采用因果分析法对粮食安全框架下的粮食生产和生态保护的演进关系、影响形式和内容进行了研究,最终给出了二者协调发展的粮食宏观调控政策设计对策。[结果]首先,不合理粮食生产活动对生态环境造成的严重破坏,主要体现在水土流失、水资源浪费、化学物质的残留和生态环境的污染;其次,被破坏的生态环境反过来影响了粮食生产的数量和质量,进而对粮食安全产生了威胁。[结论]为了保证粮食安全的目标,长期牺牲生态环境的做法已经带来了严重的后果,这种后果不仅仅表现为当前的生态失衡,更严重威胁了未来的粮食安全。因此,要充分发挥粮食宏观调控政策的作用,加强生态功能设计,具体可从建立农业自然资源保护和有效利用的制度机制、加强政府生态农业的主导型地位及投入水平、以技术进步支撑保护农业生态和粮食安全和以法律手段规范保证相应措施的顺利实施4个方面进行设计和完善。  相似文献   

5.
目的 研究数字经济对粮食生产碳排放的影响及其作用机制,在“双碳”目标下为中国粮食生产实现低碳可持续发展找准减碳动能和路径提供参考。方法 文章基于2011—2019年长江经济带108个地级市粮食种植统计数据,运用碳排放系数法从化肥、农药使用等6个碳排放源测度碳排放水平,基于动态面板模型考察数字经济对粮食生产碳排放的影响,进一步采用中介效应模型从“技术效应”和“结构效应”视角考察其减碳机理。结果 (1)数字经济发展显著降低了粮食生产中的碳排放水平,数字经济每提高1%,粮食生产碳排放强度下降7.8%,经过稳健性检验结果仍然可信;(2)数字经济在粮食生产中的碳减排效应存在明显的异质性,一是在中东部地区、粮食主产区和产销平衡区其减碳作用更大也更显著,二是在地形平坦的平原的减碳效应明显大于土地禀赋稍差的山地、丘陵地区,三是2015年实施的化肥“零增长”政策显著强化了减碳效果;(3)粮食生产技术进步的“技术效应”和粮食种植规模化、专业化的“结构效应”,是数字经济削减粮食生产碳排放的重要作用机制。结论 作为新兴关键生产要素,数字经济快速延伸和渗透到粮食生产环节,可以有效提升粮食生产技术水平和种植规模化、专业化水平,进而推动粮食生产低碳高质量发展。  相似文献   

6.
王科 《中国农史》2007,26(2):122-129
为了改善农村金融、复兴农村经济,江宁实验县引入了合作运动,并为此建立了一套比较完备的合作体系,成为合作运动的运行基础,然而体系完备并不意味着就能达到它的预设目标,主观预设和客观效果之间必然存在一定的差异,因为这场运动所能达到的实际效果不仅取决于运动推广者的主观努力,也受制于当时客观的时代环境。作为一场经济运动,江宁的乡村合作运动在客观上还是取得了一定的社会经济效果,但从总体上来看,其效果又是有限的,乡村社会经济并未因此而发生太大的结构性变动。  相似文献   

7.
This article presents a political economy model of public standards in an open economy. We use the model to derive the political optimum and to analyse different factors that have an influence on this political equilibrium. We analyse the relationship between trade and the political equilibria and compare the political outcome with the social optimum to identify under which cases political considerations lead to standards being set ‘too low’ or ‘too high’, and which standards could be labelled as protectionist measures.  相似文献   

8.
Grains are the most important group of products in the food security programs of the Arab countries. These countries suffer from a shortage of food in general and in particular a shortage of grains. This results from a rapidly growing population and growing disposable incomes. This paper describes the grain sector in the economy of the Arab countries with special attention to its role in the national and regional food security programs. First, output and consumption of grains between 1973 and 1984 are analysed in all Arab countries, with special attention to wheat. Second, the concept of food security is discussed. Food security is defined as continuity of food supply to the whole population and unhampered access to food by all groups of the population. Food security is considered principally as a problem of short-term variability of food production and instability of imports. Food insecurity is thus measured by the size of production and consumption variability in relation to the long-term levels of consumption and production. The standard deviation and the coefficient of variation are used as indicators of the variability. Last, strategies and policies for achievement of food security are discussed. The growing food supply gap in the Arab countries implies the need to increase grain production as an element of major importance in the development of food-security programs. Proper grain policies must foresee increases of yields, reduction of post-harvest losses, and increased capacity to handle and store grain reserves. The establishment of national and regional Arab strategic grain stocks equal to the average magnitude of harvest shortfalls is recommended as one measure of short-term strategy. The long-term strategy, in turn, focuses on development of domestic agricultural production and greater cooperation among the Arab countries.  相似文献   

9.
Chronic food production deficits since the early 1970s have prompted policymakers of Burkina Faso to emphasize technological research with the goal of increasing the production of the most-consumed locally-grown cereals: sorghum, millet and maize. Meanwhile, urban consumers have been developing preferences for rice and wheat, cereals that are primarily imported. This study estimates demand relationships among food items in Ouagadougou, Burkina. The results of the estimation suggest that prices, income, household composition, education, marital status and urbanization were jointly important in explaining household expenditure allocations. Both local and imported cereal consumption responded positively to an income increase. However, incremental income changes would lead to relatively greater consumption of locally produced cereals by low-income households whereas high-income households would consume relatively more wheat and rice. The household model is then used to demonstrate its relevance in addressing food policy issues, by forecasting the levels of urban grain demand under alternative income and demographic scenarios. With increased production due to advances in technology, the urban demand levels do not exhaust the rural surplus of local cereals, but deficits persist in the rice-wheat sector. The results underscore the importance of technological research since Burkina could become self-sufficient in at least the production of sorghum, millet and maize.  相似文献   

10.
供给侧生产端变化对中国粮食安全的影响研究   总被引:2,自引:0,他引:2  
在“谷物基本自给、口粮绝对安全”的粮食安全战略背景下,粮食供给侧生产端对于保障中国粮食安全起到关键性作用。近年来,随着城镇化和农业现代化的推进,新型农业经营主体和土地规模化经营快速发展,粮食生产在质量效益和专业化水平不断提高的同时,其土地生产效率的提高和市场风险的防范面临挑战;粮食生产成本的攀升和比较收益的下降,使农业支持家庭生计的功能不断弱化,导致农户种粮意愿普遍降低;居民食物消费结构升级引致种植结构调整,使保障口粮绝对安全的政策成本上升。粮食生产主体结构与行为、生产成本与比较收益、供需匹配关系等生产端的重要变化,对粮食供给能力进而对国家粮食安全产生重要影响。为此,需要优化粮食安全目标,合理协调“保产量”与“优结构”的关系;完善价格激励机制,以需求升级为导向优化生产结构;优化收储调控机制,增强粮食安全风险应对能力;多举措提高农户种粮和地方政府发展粮食的积极性的同时充分利用国外资源和国际市场。  相似文献   

11.
There are many visions on how to achieve a sustainable agriculture that provides enough food and ecosystem services for present and future generations in an era of climate change, increasing costs of energy, social unrest, financial instability and increasing environmental degradation. New agricultural systems that are able to confront the challenges of a rapidly changing world require a minimum of ten attributes that constitute the defining elements of a Green Agriculture. A major challenge is to identify a set of thresholds that any agricultural production strategy must meet, beyond which unsustainable trends caused by the farming technologies would lead to tipping-point phenomena. Only those styles of agriculture that meet the established threshold criteria while advancing rural communities towards food, energy and technological sovereignty would be considered viable forms of Green Agriculture. Considering the diversity of ecological, socio-economic, historical and political contexts in which agricultural systems have developed and are evolving in, it is only wise to define a set of flexible and locally adaptable principles and boundaries of sustainability and resiliency for the agroecosystems of the immediate future.  相似文献   

12.
The European Commission defines the bioeconomy as a “transition economy which seeks to increase efficiency, optimize use and decrease environmental impact through the reduction of waste and greenhouse gas emissions.” However, attempts to substitute or control nature through efficient bio‐based technology have not lived up to expectations and much of the industry still relies on globally sourced biomass to drive the bioeconomy. This article examines the social and political economic relations surrounding small‐scale production of the feedstock castor oil plant (castor, Ricinus communis) in the deep south of Madagascar. Theorizing the bioeconomy through the lens of a “small‐scale commodity frontier,” it builds from recent injunctions by Jason Moore to show how the appropriation of cheap nature (including paid and unpaid labour) is both historically and geographically co‐produced. The castor value chain is held up as a way to transform regional economies and a “silver bullet” to alleviate poverty and address food security in some of the most economically marginal areas of Madagascar. We adopt a regional and feminist political ecology approach to illustrate what is behind this discursive cloak of “development imaginaries,” making visible the social relations surrounding castor production and demonstrating the historical marginalization involved in producing the frontier.  相似文献   

13.
种粮大户作为新型农业生产经营的重要组成部分,对提高农民收入、提高种植效率及拉动地方经济收入具有重要作用。文章利用调查研究方法,对广东省种粮大户的经营状况进行调查,结果显示:目前广东省大户经营耕地面积规模普遍在3.3~6.6hm~2,经营方式有4种类型,大户年龄结构趋于合理区间。在这基础上对广东省种粮大户发展情况及意愿表达进行分析,认为广东省种粮大户在生产经营中面临着生产融资困难、农田基础设施薄弱及土地流转受阻等诸多问题,并提出应加大财政支持;建立健全土地流转机制;完善贷款机制;大力发展农业保险,增加抗风险能力;提高社会化服务,提高种粮大户素质;提高农业机械化水平等促进广东省种粮大户健康发展的对策建议,对促进广东省粮食生产,保证地区粮食安全及相似省份粮食生产都具有现实和重要指导意义。  相似文献   

14.
藏粮于地战略与路径选择   总被引:4,自引:0,他引:4  
针对长期实施的藏粮于仓、以丰补歉策略所带来的一系列问题,中央提出实施"藏粮于地"战略。何为"藏粮于地"?实施"藏粮于地"有何益?实施"藏粮于地"面临哪些挑战?如何实施"藏粮于地"?对此,文章进行了系统分析论述。我国粮食生产"十二连增",粮食库存丰富,粮食生产稳定性增强,近年国际粮食价格低廉,这些为我国实施"藏粮于地"战略创造了条件。然而,实施"藏粮于地"并非易事,面临许多问题与挑战,包括:耕地面积有可能再次大幅减少,耕地质量堪忧;水资源约束日益突出,粮食生产能力提升的难度越来越大;农业抵御自然灾害的能力低,农业自然灾害突出;规模化生产经营与社会化服务水平低,粮食生产调控能力弱;国内粮食生产大萎缩和世界粮食价格危机有可能再现,冲击"藏粮于地"行动计划。实施"藏粮于地",关键在"地",核心在"藏"。数量充足和高质量的耕地是基础,同时,还必须有完好的"养地"与"用地"机制。因此,应强化"护地"、"建地"、"养地"与"用地",即走护、建、养、用"四结合"之路。  相似文献   

15.
Food safety regulations aimed at controlling food contamination have sometimes been criticised as excessive burdens, disadvantaging smaller firms and exports from developing nations. Reported food safety expenditures appear relatively small (from <1 to 7% of the value of production) but can erode profit margins for many firms. This article responds to claims that reported firm‐level expenditures do not reflect true costs of compliance with food safety systems. We estimate incidental cost savings and uncounted costs associated with Hazard Analysis and Critical Control Points (HACCP) certification among Philippine seafood producers by modelling the interactions between conventional production and food safety expenditures using translog cost functions. Results indicate a significant underestimation of reported HACCP costs by an average of US$1.10 for a dollar of reported expenditure.  相似文献   

16.
This empirical study uses 100 years of annual data on 11 agricultural commodities from Belgium to measure the impact of structural changes coinciding with economic development and changes in political institutions on agricultural protection. The analysis shows that changes in agricultural protection are caused by a combination of factors. Governments have increased protection and support to farmers when world market prices for their commodities fell, and vice versa, offsetting market effects on producer incomes. Other economic determinants were the share of the commodities in total consumer expenditures (negative effect) and in total output of the economy (positive effect). With Belgium a small economy, there was no impact of the trade position. Changes in political institutions have affected agricultural protection. Democratic reforms which induced a significant shift in the political balance towards agricultural interests, such as the introduction of the one‐man‐one‐vote system, led to an increase in agricultural protection. The integration of Belgian agricultural policies in the Common Agricultural Policy in 1968 coincided with an increase in protection, ceteris paribus. Both institutional factors, related to changes in access to and information about the decision‐making at the EU level, and structural changes in the agricultural and food economy may explain this effect.  相似文献   

17.
Nigeria's once thriving plantation economy has suffered under decades of state neglect and political and civil turmoil. Since Nigeria's return to civilian rule in 1999, in a bid to modernize its ailing agricultural economy, most of its defunct plantations were privatized and large new areas of land were allocated to ‘high-capacity’ agricultural investors. This paper explores the local tensions associated with this policy shift in Cross River State, which, due to its favorable agro-ecological conditions and investment climate, has become one of Nigeria's premier agricultural investment destinations. It shows how the state's increasing reliance on the private sector as an impetus for rural transformation is, paradoxically, crowding out smallholder production systems and creating new avenues for rent capture by political and customary elites. Moreover, as Nigeria's most biodiverse and forested state, the rapid expansion of the agricultural frontier into forest buffer zones is threatening to undermine many of the state's conservation initiatives and valuable common pool resources. The paper goes on to explain why and how private sector interests in Cross River State are increasingly being prioritized over natural resource protection, indigenous rights over the commons, and smallholder production systems.  相似文献   

18.
Food security for the world in 2025 is possible and probable if the right set of things are done, starting now. But the task will not be easy. It is both a technology and a political/economic challenge. The challenge for sub-Saharan Africa is even greater. While other regions improved per capita food availability over the last 30 years, Africa's availability declined. But food security is about more than supply. It is also about access which means income generating employment is critical. Meeting future requirements in Africa and the world will require sustainable intensification of complex production systems, appropriate national and international policies and continued investments in agricultural research. Without these conditions and increased employment intensive growth, prospects for the future are less bright.  相似文献   

19.
Perennial grain crops may play an important role in environmentally sound and socially just food systems for Africa. We study the future possibility of integrating perennial grains into Malian farming systems from the perspective of agroecology, and more specifically using a gendered space approach. We interviewed 72 farmers across the sorghum-growing region of Mali. We found that perennial grains offer a vision for transforming human relations with nature that mirrors the resource sharing of customary land tenure, including patterns of extensive and intensive land use in time and space. Women interviewees identified a broad set of potential advantages and challenges to perennial grain production. Advantages include reduced labour, saving seed, and improving food security. Women farmers were concerned about livestock, water access, and resource limitations. We argue that perennial grains may increase access to land and natural resources for women farmers. Perennial grains may improve soil quality, reduce labour early in the rainy season, and provision more resources from fallow lands. Pastoralists stand to benefit from improved pastures in the dry season. We conclude that investments are needed to develop viable crop types in consideration of the complexity of West African farming systems and the local needs of women farmers and pastoralists.  相似文献   

20.
Currently, a large portion of grain production is funneled into animal feed despite widespread hunger and undernutrition. In the present work we: (i) estimated the area, water and carbon footprints of animal-source proteins (AP) obtained from intensive farming systems and compared them with those from producing an equivalent amount of plant-source proteins (PP); (ii) postulated a set of straightforward hypotheses to recover environmental resources by cutting down a surplus in the per capita protein intake from three representative regions where intensive animal farming systems account for a great share of animal food production.Our major findings revealed that AP from intensive farming were approximately 2.4 to 33 more expensive in terms of area and water demand and 2.4 to 240 more pollutant in terms of greenhouse gas emissions when compared with PP. Environmental recoveries varied widely according to the hypothesized scenarios, but even the lowest estimates suggested remarkable results.Whether additional proteins supply would be required, crops with large protein content as peas, chickpeas, soybeans, and lupins could help to meet food security, while better compromise between dietary habits and environmental protection could be reached in rich countries by a moderate consumption of meat produced with non-feed grain systems.  相似文献   

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