Feeding 10 billion people: Limiting nitrogen fertilizers does not reduce productivity
Limiting nitrogen fertilizers does not reduce productivity
Reducing the use of nitrogen fertilizers is possible and would benefit the environment and health by saving agricultural crops capable of feeding 10 billion people, researchers say in a study published in the prestigious scientific journal Nature.
Spreading in a cornfield in Illinois.
James Baltz / Unsplash
The study, published Jan. 4 by an international team of researchers that analyzed more than 1,500 records of farmland around the world, presents 11 urgently needed reforms to reduce fertilizer pollution without sacrificing productivity, particularly through crop rotation, or the “nitrogen” system. . loans”.
The benefits of reducing agricultural nitrogen pollution are about 25 times greater than the costs of implementing these measures, which the study estimates at $34 billion a year, the scientists write.
For China and India, whose heavy use of fertilizers makes them the world’s biggest nitrogen polluters, the cost would be about $5 billion and $3 billion, respectively.
Conversely, reduced premature mortality and environmental damage caused by nitrogen pollution, as well as increased agricultural production, could represent benefits of nearly $500 billion.
“Given the multiple effects of reactive nitrogen derivatives on health, climate and the environment, they should be reduced in all media such as air and water,” explains the author to AFP Director, Professor Baojing Gu of Zhejiang University in China. .
But the proposed measures could also “lead to less carbon sequestration by ecosystems, a ‘slight’ negative impact on climate change,” Mr Gu adds.
Despite significant long-term benefits, nitrogen management reform has prohibitive start-up costs for many smallholder farmers unless supported by strong public policy.
However, a system of “nitrogen credits” can subsidize farmers who adopt these innovative techniques. Funding can be raised by taxing food products or polluting activities and products to start this virtuous circle.
“Nitrogen Cycle”
The authors note that widespread use of chemical fertilizers has helped quadruple the human population over the past century and remains essential to feed 9.7 billion people by 2050.
But the crop explosion made possible by the agricultural revolution came at the expense of the environment. Today, more than half of the nitrogen in fertilizers ends up in the air and water, causing toxic pollution, soil acidification, ozone depletion and biodiversity loss.
The world is naturally full of nitrogen, which is essential for all life on earth, especially plants.
About 80% of the atmosphere is gaseous (N2), but it is of little use to most living organisms until microbes convert it to the metabolizable ammonia.
This process sends about 200 million tons of nitrogen to the land and oceans every year. Nitrogen in various forms finds its way into the atmosphere thanks to bacteria, especially after being spread or burned in wetlands or oceans.
Research shows that this natural “nitrogen cycle” is massively thrown out of balance by the use of about 120 million tons of chemical fertilizers every year.
Less than half of this human contribution is actually absorbed by plants, while the rest permeates the environment with its nuisance.
Humanity’s challenge is to stop filling the soil with nitrogen and find a solution to reduce its nitrogen footprint… Trying to reduce its carbon footprint in the fight against global warming.
AFP
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