Both products can be worked up together as straight nitrogen fertilizer.

The long-term supply outlook for oil and gas, the key source of nitrogen fertilizer, is poor.

This comes from nitrogen fertilizers that us humans are using.

Beds are given frequent light application of nitrogen fertilizer during the first year.

Some form of nitrogen fertilizer is needed if levels are below this range.

On the other hand, if levels are above this range, addition of nitrogen fertilizer will not increase crop yield.

Ten percent of the nitrogen fertilizer needed for farming is made by lightning.

Go easy on nitrogen fertilizer, which will promote soft green growth, not flowers.

How can nitrogen fertilizer be a pollutant if it's good for plants?

Don't feed them, at least not with high nitrogen fertilizer.