Research

Environmental cost of agriculture: Soil determines fate of phosphorus

We’re not in Iowa anymore

What was once considered poor agricultural land in Brazil now has soybean yields like Iowa’s. Phosphorous is a key, but overuse can harm waterways and deplete global supplies. How much is too much? That depends on the soil. Researchers compared three soybean-growing regions.

Brazil’s soybean yields have become competitive with those of the United States and Argentina, but the soil demands a lot of phosphorus, which is not renewable. In the United States, meanwhile, historical applications of the fertilizer have polluted waterways. What accounts for these problems? It’s the soils, according to a new study comparing agriculture in the three countries.