The Water Cost of Agricultural Diversity
Abstract
Agriculture is by far the largest human-induced water use sector, and as such, it plays an important role in measures that aim to alleviate water scarcity. The cropping pattern, i.e. which crops are grown where, is affected directly or indirectly by many of these measures. Optimization of cropland allocation may lead to specialization, such as large monocultures of specific crops in areas most favorable for them. This may negatively affect food security and increase economic risk to producers. Monocultures are more susceptible to plant diseases and offer less security against other threats such as crop-specific vulnerabilities towards climate variability than a diverse crop mix.
This study quantifies the price, in terms of water, imposed by accepting less water-efficient but more diverse cropping patterns globally. We use a linear optimization model to find the cropping pattern that represents the greatest overall water efficiency and, alternatively, smallest departure from the evapotranspiration of potential natural vegetation. We then compare these results with scenarios where optimization constraints limit the degree of decreasing the variety of crops currently grown in each country or region. In areas currently growing a limited variety of crops, opportunities for increasing the diversity are explored. While global or even regional optimization of cropland allocation is unlikely in practice, the scenarios illustrate that there are trade-offs between different measures of efficiency and resilience.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC43H1412J
- Keywords:
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- 0495 Water/energy interactions;
- BIOGEOSCIENCES;
- 0299 General or miscellaneous;
- GEOHEALTH;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 6309 Decision making under uncertainty;
- POLICY SCIENCES & PUBLIC ISSUES