Scientists have created a map showing where the world’s most important food crops should be grown to maximize yield and minimize environmental impact. This would sequester large amounts of carbon, increase biodiversity and reduce agricultural use of freshwater to zero.
The redesigned world map of agriculture includes major new planting areas for many important crops around the corn belt in the US Midwest and sub-Saharan Africa. Huge areas of arable land in Europe and India would become natural habitats again.
“If we shifted production to more suitable areas, we would see environmental benefits very quickly.” — Robert Beyer
The redesign – assuming high-intensity, mechanized agriculture – would reduce the carbon impact of global arable land by 71% by allowing the land to return to its natural, forested state. This corresponds to recording our current net CO2 emissions from 20 years. Trees sequester carbon as they grow and also allow more carbon to be sequestered from the soil than when plants are grown in it.
In this optimized scenario, the impact of crop production on the world’s biodiversity would be reduced by 87%. This would drastically reduce the risk of extinction for many species for which agriculture poses a major threat. The researchers say farmland would quickly return to its natural state, often restoring its original carbon stocks and biodiversity within a few decades.
The redesign would completely eliminate the need for irrigation by growing plants in locations where rain would provide all the water they need to grow. Agriculture currently accounts for around 70% of global freshwater consumption, resulting in drinking water shortages in many drier parts of the world.
The researchers used global maps of the current growing areas of 25 major crops, including wheat, barley and soybeans, which together account for more than three-quarters of the world’s arable land. They developed a mathematical model to study all possible ways to allocate this farmland around the world while maintaining the overall production level for each crop. This allowed them to identify the option with the lowest environmental impact.
The study will appear in the Journal on March 10, 2022 Nature communication earth & environment.
“In many places, cropland has replaced natural habitats that were high in carbon and biodiversity – and plants don’t even grow very well there. If we let these places regenerate and move production to more suitable areas, we would see ecological benefits very quickly,” said Dr. Robert Beyer, a former researcher at the University of Cambridge’s Department of Zoology and first author of the study. Beyer now works at the Potsdam Institute for Climate Impact Research (PIK), Germany.
Previous studies have identified priority areas for ecological restoration, but this is the first to plan agricultural land resettlement to maximize long-term environmental benefits without compromising food security.
While a full global resettlement of farmland is clearly not a scenario that could be put into practice right now, the scientists say their models highlight locations where farmland is currently very unproductive but has the potential to become hotspots for biodiversity and carbon storage will.
A prudent approach and reallocating farmland only within national borders rather than globally would still yield significant benefits: global carbon footprints would be reduced by 59% and biodiversity impacts would be 77% lower than current levels.
A third, even more realistic option, to relocate only the 25% of the country’s worst offending acres, would result in half the benefits of optimally relocating all arable land.
“It is currently not realistic to implement this entire redesign. But even if we shifted just a fraction of the world’s arable land and focused on the places that are least efficient for growing crops, the environmental benefits would be huge,” Beyer said.
The study comes to the conclusion that the optimal distribution of arable land will hardly change by the end of the century, regardless of how the climate changes in concrete terms.
“Optimal growing locations are not a moving target. Areas where ecological footprints would be small and crop yields high for the current climate will remain broadly optimal going forward,” said Professor Andrea Manica of the University of Cambridge’s Department of Zoology, senior author of the study.
Researchers recognize that farmland relocation must be done in a manner that is both economically and socially acceptable to the people affected. They cite examples of set-aside schemes that give farmers financial incentives to set aside part of their land for environmental benefit. Financial incentives can also encourage people to farm in more suitable locations.
The model generated alternative global distribution maps depending on the way the land is managed – from advanced, fully mechanized production with high-yielding crop varieties and optimal use of fertilizers and pesticides, to traditional, subsistence-based organic farming. Even redistributing less intensive agricultural practices to optimal locations would significantly reduce their carbon and biodiversity impacts.
While other studies show that we could significantly reduce the environmental impact of farming if we move towards more plant-based diets, the researchers say that in reality, diets are not changing rapidly. Assuming that diets will not change, their model focused on producing the same foods as today, but in optimal ways.
Much of the world’s arable land is located in areas where it has a huge ecological footprint, having replaced carbon-rich and biodiversity-rich ecosystems and putting a significant strain on local water resources. These sites were chosen for historical reasons, such as their proximity to human settlements, but the researchers say now is the time to grow food more optimally.
Reference: “Relocating farmland could drastically reduce the environmental impact of global food production” by Robert M. Beyer, Fangyuan Hua, Philip A. Martin, Andrea Manica and Tim Rademacher, March 10, 2022, Communication Earth & Environment.
This research was funded by the European Research Council.
https://scitechdaily.com/relocating-farmland-could-increase-biodiversity-and-turn-back-clock-20-years-on-carbon-emissions/ Shifting farmland could increase biodiversity and turn back the clock on carbon emissions by 20 years