This is Part 2 in Jim’s series. If you missed Part 1, here you go! When you feed hay for fertilizer, we often think of it as a way to reduce the need for purchased fertilizer, especially Nitrogen (N).
Have you thought about how much N you may actually be applying when you feed hay?
It may be more than you think.
Let’s Look at How N Moves From Fed Hay Back to the Soil
The amount of nitrogen in hay is directly tied to the protein content of the hay. Protein on average contains 16% N. Grass hay may have less protein than the livestock being fed require while legume hay generally has much more protein than required.
If the hay is just what the animal needs in terms of protein content, then about half of the N will be excreted in the feces and a half in the urine.
Livestock will generally excrete 85 to 95% of the N consumed.