During training, members of the military fire hundreds of thousands of bullets and artillery at firing ranges. Unfortunately, many of those shells are never retrieved, posing an environmental issue: they don’t degrade for hundreds of years. So the military wants to find a way to make biodegradable bullets, complete with plant seeds, according to Engadget.

The Department of Defense is soliciting proposals for biodegradable ammunition loaded with seeds that will grow into plants beneficial to the environment—ones that eliminate contaminants from corroding ammunition. The seeds would only start growing after a few months in the ground.

It’s not necessarily carelessness that leaves ammunition lying around where it can corrode and cause environmental damage. Sometimes the cartridge casings become lodged several feet underground, making it impossible to find them. Other times, civilians might find the casings, but not know whether to pick them up or not.

With so many training rounds manufactured and used by the Army each year, a new type of bullet could have an enormous impact. If these rounds could be used on the battlefield, the significance would be even bigger.

Proposals are due on February 8.

[h/t Engadget]