Scientists have created a map showing where important food crops in the world should be grown in order to maximize yield and mitigate environmental impacts. This would capture substantial amounts of carbon, increase biodiversity, and reduce agricultural use of freshwater to zero.
The reimagined world map of agriculture includes large new farming areas for many large crops around the cornbelt in the midwestern United States and beneath the Sahara desert. Many large agricultural areas in Europe and India would be restored to natural habitat.
The increase - assuming high-input, mechanised farming - would reduce global croplands'' carbon footprint by 71%, allowing land to revert to its natural, forested state. This is equivalent to capturing twenty years worth of our current net CO2 emissions. Trees eat carbon as they grow, and also enable more carbon to be captured by the soil than when crops are grown in it.
In this optimized scenario, the impact of crop production on the worlds biodiversity would be reduced by 87%. This would significantly reduce the risk of many species, for which agriculture is a major challenge. Croplands will quickly reintroduce their original carbon stocks and biodiversity, often within a few decades.
This would eliminate the need for irrigation altogether, by bringing crops to an extent where rainfall provides all the water they need to grow. Agriculture is currently responsible for around 70% of global freshwater use, and this is leading to drinking water shortages in many dry countries.
The researchers used global maps of the current growing areas of 25 major crops, including wheat, barley, and soybean. These combined accounts for more than three quarters of croplands across the globe. This allowed them to identify the best candidate for environmental impact.
Today, the study is published in the journal Nature Communications Earth & Environment.
In many cases, cropland has resupplied natural habitat that contained a lot of carbon and biodiversity, and crops do not even grow very well there. If we let these places regenerate, and moved production to better suited areas, we would see environmental benefits very quickly, according to Dr Robert Beyer, who formerly worked for the Department of Zoology at the University of Cambridge, and the first author of the study. Beyer, now based at the Potsdam Institute for Climate Impact Research (PIK) in Germany.
Priorities for ecological restoration have been identified by previous studies, yet this is the first time that agricultural land has been relocated to maximise long-term environmental benefits without compromising food security.
While a complete global relocation of cropland is certainly not a possibility that could be implemented, the researchers say their findings show that areas where cropland are currently extremely unproductive, but they may be beneficial beneficial sources of biodiversity and carbon storage.
Only redistributing croplands within national borders rather than internationally would provide significant benefits: global carbon impact would be reduced by 59%, and biodiversity impact would be 77% lower than at present.
A third, even more realistic option of only relocate the worst-offending 25% of croplands across the country would result in half of the benefit of optimally moving all croplands.
It''s currently impossible to do this entire redesign. However, even if we only relocated a small portion of the world''s cropland, focusing on the areas that are less efficient for growing crops, environmental benefits would be enormous.
Regardless of the climate''s potential, the optimal planting rate will be limited until the end of the century.
According to Professor Andrea Manica, the researcher of the Department of Zoology at the University of Cambridge, optimal cropping sites are no moving goals. Areas where environmental footprints would be low, and crop yields would be high in the future, according to the researcher.
Researchers believe that relocating cropland must be done in an environment that is acceptable to the person it affects, both economically and socially. They cite examples of set-aside initiatives that allow farmers to retire a portion of their land for environmental benefit. Financial incentives can also encourage people to farm in better-suited locations.
Alternative global distribution maps were derived depending on how the land is grown, from advanced, fully mechanized production with high-throughput crops and optimal fertilizer and pesticide applications, to traditional subsistence-based organic farming. Even redistribution of less intensive farming practices to optimal locations would significantly reduce their carbon and biodiversity impacts.
While other studies suggest that if we moved towards more plant-based diets, we might significantly reduce the impact of agriculture, they say, in reality, diets aren''t changing rapidly. Their approach suggested that diets will not change, and that they concentrate on producing the same food as today but in an optimal manner.
Many of the world''s croplands are located in areas where they have a significant environmental footprint, which have replaced carbon-rich and biodiversity-rich ecosystems. These areas have been chosen for historical reasons, such as their proximity to human settlements, but experts say it''s now time to cultivate food in a more beneficial manner.