Home / Environment / Hidden Danger: Phosphorus Overload in Farmland
Hidden Danger: Phosphorus Overload in Farmland
26 Jan
Summary
- Phosphorus fertilizer has accumulated in US farmland for decades.
- Excess phosphorus pollutes waterways, causing algal blooms and dead zones.
- Outdated soil tests inaccurately measure available phosphorus levels.
A significant environmental challenge is building unseen in U.S. farmlands: decades of phosphorus accumulation. Farmers have historically applied phosphorus fertilizer as a safeguard, leading to levels far exceeding crop needs. This excess nutrient, unlike nitrogen, sticks to soil but can be carried into waterways through erosion and runoff.
This phosphorus fuels explosive algal growth, creating eutrophication and oxygen-depleted dead zones. Some blooms also release toxins, threatening drinking water and costing communities millions. Warmer temperatures exacerbate this issue by reducing water's oxygen-holding capacity.
Flawed, decades-old soil tests often fail to accurately assess available phosphorus, especially in diverse soil types. This mismatch leads farmers to apply unnecessary fertilizer, increasing pollution risks. Researchers are developing improved methods that mimic plant uptake to better guide fertilization decisions.
Implementing these advanced testing methods can help farmers manage phosphorus application more precisely. This approach allows for reduced fertilizer use, saving money and protecting water quality while still ensuring agricultural productivity and drawing down existing legacy phosphorus.
