Reduced / Sequestered
(To Implement Solution)
Nitrogen fertilizers have vastly improved the productive capacity of agricultural systems in the past century. Some of the synthetic nitrogen is taken up by crops, increasing growth and yield. The nitrogen that is not utilized by plants, however, causes untold problems:
- Chemically destroying organic matter in the soil.
- Seeping into waterways; creating algal blooms and oxygen-depleted oceanic dead zones; and causing major fish kills.
- Causing global warming, as soil bacteria convert nitrate fertilizers into nitrous oxide—298 times more powerful than carbon dioxide in its warming effect.
Nitrogen can be more efficiently managed to reduce these effects by attending to the Four R’s:
- Right source: matching fertilizer choices with plant needs.
- Right time and right place: managing fertilizer applications to deliver nitrogen when and where crop demand is highest.
- Right rate: ending over-application of fertilizer as “insurance.”
Implementation of this solution is simple: It requires farmers to moderately reduce their inputs rather than undertake a new practice or install a new technology. Education, assistance, incentives, and regulation can accelerate adoption. The true solution to nutrient management, however, is rotational, regenerative land practices that eliminate most, if not all, need for synthetic nitrogen.
By reducing fertilizer overuse on a total of 380-817 million hectares of farmland by 2050—up from an estimated 139 million hectares currently—avoided nitrous oxide emissions could equal 2.3-12.1 gigatons of carbon dioxide. No investment is required, and farmers could save $23-70.8 billion from reduced fertilizer costs. Our analysis assumes adoption that roughly parallels conservation agriculture, as farmers are likely to be amenable to both practices.