Apart from fertilizers and water, what else is needed for a better agriculture yield? A new study shows that if air pollution is decreased, especially the amounts of nitrogen oxide pollution, the results would change and the farmers would get a better yield.
Researchers from the Stanford University concluded that reducing NOx emissions by about half in each region would improve yields by nearly ten per cent for both winter and summer crops in Western Europe, and roughly eight per cent for summer crops and six per cent for winter crops in India. North and South America generally had the lowest NOx exposures. Overall, the effects seemed most negative in seasons and locations where NOx likely drives ozone formation.
The U.S. National Science Foundation-supported analysis, published in Science Advances, findings have great significance for increasing agricultural output and analyzing climate change mitigation costs and benefits around the world.
Pointing out that new satellites were able to map nitrogen oxides, which are invisible to humans, study lead author David Lobell said, “since we can also measure crop production from space, this opened up the chance to rapidly improve our knowledge of how these gases affect agriculture in different regions.”
METHOD
Lobell and his colleagues combined satellite measures of crop greenness and nitrogen dioxide levels for 2018-2020. Though invisible to humans, nitrogen dioxide has a distinct interaction with ultraviolet light that has enabled satellite measurements of the gas at a much higher spatial and temporal resolution than for any other air pollutant. “In addition to being more easily measured than other pollutants, nitrogen dioxide has the nice feature of being a primary pollutant, meaning it is directly emitted rather than formed in the atmosphere,” said study co-author Jennifer Burney of the University of California, San Diego.
“The actions you would take to reduce NOx, such as vehicle electrification, overlap closely with the types of energy transformations needed to slow climate change and improve local air quality for human health,” said Burney. “The main take-home from this study is that the agricultural benefits of these actions could be really substantial, enough to help ease the challenge of feeding a growing population.”
Manda Adams, a program director in NSF’s Division of Atmospheric and Geospace Sciences said that the result showed how coupled is human system with Earth system processes. Actions taken by society to reduce pollution such as NOx emissions may be aimed at human health and slowing greenhouse gases, with benefits to society, Adams added.
NITROGEN OXIDES
Nitrogen oxides are among the most widely emitted pollutants in the world. These gases can directly damage crop cells and indirectly affect them through their role as precursors to formation of ozone, an airborne toxin known to reduce crop yields, and particulate matter aerosols that can absorb and scatter sunlight away from crops. While scientists have had a general understanding of nitrogen oxides’ potential for damage, little is known about their actual impacts on agricultural productivity. Past research has been limited by a lack of overlap between air monitoring stations and agricultural areas, and confounding effects of different pollutants, among other challenges to ground-based analysis.
