Crop production and food security go hand in hand. Farmers and researchers have long focussed on how to improve crop production, looking for gains to be made from better soil preparation, fertilizers, irrigation, pest control and selecting more productive cultivars. However, there are factors outside of their control, such as weather and air pollution.
Air pollution is known to affect crop production. This can occur through direct injury to leaf tissue, effects on growth and yield, or indirectly through subtle changes to a crop that makes it sensitive to other stressors. A recent study by researchers at Stanford’s Center on Food Security and the Environment, has found that nitrogen oxides (NOx) can significantly reduce crop yields. They used satellite measurements of crop greenness and NOx levels for crops in several major agricultural regions. Overall they found that crop growth is negatively associated with NOx levels and because air pollution is generally worse in winter, the effect on winter crops can be greater.
How serious was the effect of air pollution on crop yields? The researchers calculated that if the NOx levels were reduced by half yields in China would increase by about 25% for winter crops and 15% for summer crops, in India by about 8% for summer crops and 6% for winter crops, in Western Europe by about 10% for both winter and summer crops.
This research was possible because of recent advances in satellite observations allowing improved air pollution monitoring.