February 2021: One third of fertilizer to grow corn in the US is absorbed by the soil to bring nutrient levels back to pre-farmed levels instead of increasing yields. Considering the costs of fertilizer, the cost of nutrient loss due to high yield farming, and the impact of fertilizer on ecosystems, soil degradations costs farmers a half billion dollars every year. It highlights the needs to accelerate the transition to regenerative agricultural practices.
Information
Farming communities around the world are experiencing long-term declines of soil fertility. Often, declining soil fertility is linked to salinization, acidification, erosion, and the loss of critical nutrients in the soils such as nitrogen and phosphorus. New evidence finds that one third of the fertilizers applied in the US to grow corn only compensate for ongoing loss of soil fertility instead of increasing yields. It suggests that the soil degradation costs US farmers more than half billion dollars in extra fertilizer costs every year. Considering the money spent on fertilizer, costs of nutrient loss and ecosystems impact to, for example, the Mississippi River, researchers estimate soil degradation could costs a trillion dollars each year. The US is one of the largest producers of corn globally and generated $14.5 billion in revenue during the 2018-2019 growing season. To achieve high yields, the US are one of the largest users of fertilizer in the world with 10% of agricultural GHG emission being traced to fertilizer use.
Implications and opportunities
Increased visibility of how much fertilizer is needed to bring back soil fertility to pre-farmed levels rather than increasing yields, supports farmers in their decision-making about farming practices. The information could incentivise farmers to transition to more sustainable forms of agriculture and accelerate the move away from high-yield agricultural systems. In addition to the economic costs to farmers and GHG emissions, the over-use of fertilizers can have environmental impacts. For example, runoffs containing nitrogen and phosphorus from fertilizers can change soil compositions and often reaches rivers, lakes, and other water systems. These runoffs can create harmful environments for freshwater and marine lives that communities depend on. The referenced papers calls for policy makers, business leaders and farmers to incentivise the transition to a regenerative agriculture to minimiser fertilizer costs, negative impacts on ecosystem from fertilizers, and costs due to soil nutrient loss from high yield farming.
Limitations
The referenced study uses the Environmental Policy Integrated Climate model to estimate economic impacts from fertilizer use in the US. The model is a widely used agronomic model, but all results should be seen within the context of the model’s limitations and the data input.
Sources
Jang, W., et.al. (2020). The hidden costs of land degradation in the U.S. maize agriculture. Earth’s Future. DOI: 10.1029/2020EF001641
Strickler, J., (2020). Soild loss costs U.S. corn farmers half a billion dollars each year. Retrieved from https://www.forbes.com/sites/jordanstrickler/2021/01/13/soil-loss-costs-us-corn-farmers-half-a-billion-dollars-each-year/?sh=2719bd915190
