Genetic diversity and interdependent crop choices in agriculture☆
Section snippets
Trends in genetic diversity in agriculture
Are we deploying sufficient genetic diversity in agriculture? The level of genetic diversity that characterizes commercially important crops and animals is a matter of considerable concern, as it is generally agreed that access to genetic diversity has been and remains important in maintaining and increasing agricultural productivity. There are economic and epidemiological reasons to believe that the varietal choices made by farmers may lead to less genetic diversity in agriculture than is
The role of genetic diversity
What is at stake in this discussion? The key point is that a loss of genetic diversity may lead to significant risks for food supplies. A pathogen that attacks the predominant commercial variety of a food crop can inflict immense costs on society. The classic example of this is the Irish potato famine of the 19th century. More recently, the loss of a significant fraction of the Asian rice crop to the grassy stunt virus2 illustrates the same point—the extreme vulnerability of a
Genetic diversity and risk management
In growing food, as in many other areas, society faces a risk–return trade off. It can enhance the productivity and average yield of food crops at the cost of greater risk, measured by a higher standard deviation of their yields. One illustration of this is the use of crops well adapted to particular weather patterns. If a suitable weather pattern materializes these can give yields greatly in excess of more generic crops, but if the weather pattern that is realized is not that to which they are
Policy responses
The existence of external effects between farmers implies that the overall allocation of risks in society, and indeed the overall allocation of resources, will be inefficient. The analysis of Nash equilibria above indicates that under a range of parameter values farmers will make identical choices of variety and will select too little diversity. To achieve efficiency we would need to face each farmer with a cost that indicates the extent of the external effect that he is imposing on others by
Conclusions
In summary, genetic diversity in agriculture is important. Its lack can increase social vulnerability to pathogens and increase the risks that we face with our food supplies. Genetic diversity in agricultural systems is changing, and there has been a decline in traditional crop varieties and in breeds and varieties of animals. This may be associated with growing international trade in foods and in seeds. There is now perhaps an increase in the diversity of new genes included in new varieties,
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Cited by (59)
Biodiversity and bioresources: impact of biodiversity loss on agricultural sustainability
2023, Biodiversity and Bioeconomy: Status Quo, Challenges, and OpportunitiesSoil and crop management to save food and enhance food security
2019, Saving Food: Production, Supply Chain, Food Waste and Food ConsumptionThe Expansion of Modern Agriculture and Global Biodiversity Decline: An Integrated Assessment
2018, Ecological EconomicsCitation Excerpt :Profit-maximizing farmers clear land and plant it with small numbers of high-yielding crop varieties, leading to the loss of biodiversity at the local and global scales. In this process, farmers only partially take into account their marginal impact on biodiversity, and in turn on agricultural productivity (Bowman and Zilberman, 2013; Heal et al., 2004; Weitzman, 2000). Decisions at the individual level about land conversion and crop selection thus cause an externality with respect to aggregate production.
Assessing the potential for niche market development to contribute to farmers' livelihoods and agrobiodiversity conservation: Insights from the finger millet case study in Nepal
2016, Ecological EconomicsCitation Excerpt :An important part of this loss is the unintended effect of increased agricultural intensification. While this intensification creates benefits for humanity (Cassman, 1999), there is also an increasing evidence that this loss can have important negative consequences (Heal et al., 2004; Millennium Ecosystem Assessment, 2005), including the depletion of resources with high productivity and food market potential in the type of marginal environments typically managed by poor smallholder farmers (Cavatassi et al., 2011; Di Falco et al., 2011; Coromaldi et al., 2015). In particular, within this context, the replacement of local landraces by modern varieties is recognized as one of the main drivers of on-farm crop genetic erosion (Jarvis et al., 2011; Tilman et al., 2002; Harlan, 1975) and can result in a reduction in dietary diversity (Pingali, 2012).
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This paper was drafted at the Beijer Institute Workshop at Asko in September 2000.