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1.
This research characterizes the biological diversity of millet crops in the semiarid regions of India at the household and village‐community ( panchayat) scales of analysis, placing that evidence in the context of local seed systems. A set of seed system parameters that span formal and informal exchange and can be measured empirically are proposed. The analysis is based on data collected through sample surveys of farmers and traders in selected sites of Karnataka and Andhra Pradesh, combined with cultivar taxonomies developed with geneticists and applied to seed samples. Findings demonstrate that millet crop diversity levels at both scales of analysis are significantly influenced by seed system parameters, factors which related studies have omitted. In particular, the presence of active local (formal and informal) seed markets enhances millet richness among and within farming communities. Crop improvement strategies oriented toward local seed markets could provide important benefits and incentives to farm households living in these marginal environments. There is a need, however, for an enhanced theoretical understanding of local seed markets in analyzing crop variety choices and the diversity of materials grown in less favored environments.  相似文献   

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Is there a future for small farms?   总被引:1,自引:0,他引:1  
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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   

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In an effort to improve productivity and profits, many farmers have replaced traditional livestock breeds with higher yielding alternatives. While such changes may bring about short‐term economic gains, the loss of traditional livestock breeds could result in the loss of an important genetic resource as a variety of important genetic traits adapted to local conditions gradually become less common in the population. This is a particular problem in Africa, where livestock make a substantial contribution to human livelihoods. Using the example of cattle in Kenya's pastoral livestock markets this study uses a choice experiment approach to investigate buyers' preferences for indigenous breeds such as the Maasai Zebu. The analysis employs a latent class approach to characterize heterogeneity in valuations both within and across respondents buying cattle for breeding, slaughter, or resale. The results show that there are at least three classes of buyers with distinct preferences for cattle traits and that most buyers favor exotic rather than indigenous breeds. Such preferences have implications for the conservation of indigenous cattle in Kenya and in other developing countries and suggest that some form of intervention may be required to ensure the preservation of this important animal genetic resource.  相似文献   

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In the past two decades, the use of grain to feed livestock in China has increased rapidly. A number of studies have examined demand and supply of grain for animal feed in China. Forecasts have been made. Generally, these projections have turned out to be well wide of the actual supply and demand. Further, forecasts of supply and demand for feed grains for the same time periods have differed greatly. Accurate forecasts of variables affecting supply and demand benefit both producers and consumers. Past forecasts of supply and demand of feed grain for livestock production in China are reviewed and reasons for discrepancies between projections are explored. Ways to improve projections of demand for and supply of grain for livestock feed in China are identified.  相似文献   

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This article analyzes the determinants of farm income among hillside farmers participating in natural resource management projects in El Salvador and Honduras. The farm income function was evaluated using a system of equations in which income is determined simultaneously by the farmer's decision to adopt soil conservation technologies and by the level of diversification (number of agricultural activities) on the farm. The database used comes from surveys administered to 678 beneficiaries of these projects during 2002. The econometric results suggest that all the variables related directly to land use (i.e., output diversification, soil conservation practices and structures, and the adoption of forestry systems) have a positive and statistically significant association with farm income. Also, farmers who own land enjoy higher farm incomes than those who do not. The results indicate that when investing in natural resource management projects, governments and multilateral development agencies should pay close attention to output diversification, land tenure, and human capital formation as effective instruments in increasing farm income.  相似文献   

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Cotton is one of the most important crops in West Africa and is a major catalyst of economic development in rural areas, but the sector has suffered from a decline in the world cotton price after 1999. This article exploits an unusual data set following 82 farmers over 14 years, from 1994 through 2007, to estimate a Nerlovian supply response model for cotton, maize, sorghum, and millet in long-term rotation. The resulting system of equations is estimated with two-stage least squares (2SLS), showing that this sample of Malian cotton producers have responded to prices in a relatively inelastic manner, with supply elasticities only about one-half of those estimated for producers in developed countries. Policy reforms could help producers respond more easily to prices changes, as well as to raise average productivity levels.  相似文献   

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This article uses national, quarterly data to conduct an empirical analysis of pre‐committed meat and fish demand by U.S. and Japanese households using the generalized almost ideal demand system (GAIDS). Pre‐committed demand represents the component of demand that is insensitive to both income and price adjustments. U.S. consumers are found to hold significant positive pre‐committed demand for beef and pork, while Japanese consumers appear to possess significant, positive pre‐committed demand for beef and fish. This provides evidence to partially explain observed differences in Japanese and U.S. consumer reactions to nonprice and nonincome effects in beef, pork, poultry, and fish. In addition, based on in‐ and out‐of‐sample performance, the more general GAIDS is preferred to the almost ideal demand system (AIDS) for both the U.S. and Japanese demand systems. Results lend to improved demand modeling efforts and more complete understanding of true market forces at hand in meat and fish markets for these culturally diverse consumer groups.  相似文献   

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