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Environmental Cost of Agriculture: Soil Determines Fate of Phosphorus

December 17, 2012
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.

Shelby Ruskin, a graduate student at Brown and the Marine Biological Laboratory, is a part of a team examining three soybean growing regions to analyze how the use of phosphorus and other fertilizers may harm waterways and deplete global supplies.

Just 20 years ago, the soils of the Amazon basin were thought unsuitable for large-scale agriculture, but then industrial agriculture — and the ability to fertilize on a massive scale — came to the Amazon. What were once the poorest soils in the world now produce crops at a rate that rivals that of global breadbaskets. Soils no longer seem to be the driver — or the limiter — of agricultural productivity. Stephen Porder, co-author of the study, focuses on the relationship between soils and phosphorus, a key agricultural nutrient. Read More of David Orenstein's story on the environmental cost of agriculture.