Nitrogen Fertilizer: Less Is More

Agriculture is a significant source of greenhouse gases. Though while much has been made of carbon dioxide and methane, not as much attention is paid to nitrogen oxides, called NOx gases, which are about 25 times more powerful as greenhouse gases than CO2.

The application of nitrogen fertilizer in excess of crop requirements is responsible for a great deal of these emissions, while also polluting water. Nitrogen in drinking water can be toxic to children, while excess nitrogen in aquatic ecosystems can cause oxygen depletion by promoting algae overgrowth.

Though as it turns out, much of that nitrogen fertilizer might be going to waste for no reason at all.

More fertilizer doesn't always mean more profit. That's one conclusion from a 10-year study conducted by Agricultural Research Service (ARS) scientists at the agency’s Soil Plant Nutrient Research Unit in Fort Collins, Colo., and colleagues at Colorado State University.

... The first study showed that onions used only about 12 to 15 percent of the fertilizer nitrogen applied to the crop. Much of the remainder stayed in the top six feet of soil. The next year, Halvorson and his colleagues planted corn on the same land and found that it recovered about 24 percent of the fertilizer nitrogen that had been applied to the onion crop. ...

The article's summary indicates that excess fertilization resulted in only an additional 10 bushels of corn per acre, where an acre without that excess could produce 250 bushels. High expense, low return.

It's always nice when the environmentally sensible thing turns out to just be the sensible thing.