How much nitrogen in a ton of hay?

[hillbilly beef man]

Does anyone know how much nitrogen is added to the soil after feeding a ton of hay? I buy about half my hay and feed it on my hayfields when I can. I was pondering how much nitrogen I am hauling in off of someone else's place in their hay.

 

[dun]

Probably depends on the hay you;re hauling in, if it's fertilized or not. There is a chart that shows how much of NPK is removed from haying. Not sure if that would correlate.
http://extension.missouri.edu/mcdonald/ ... ility1.pdf

 

[hillbilly beef man]

I read somewhere that 70 % of the nitrogen in hay is passed on through the cow in manure and urine, so this gives me an idea. Thanks Dun.

 

[u4411clb]

The question would be how much is left since most put out hay in winter time when it is too cold for the nitrogen to take affect. I would have to wonder how much would be left from the hay by the next spring when temps are back up.

 

[Bigfoot]

The question would be how much is left since most put out hay in winter time when it is too cold for the nitrogen to take affect. I would have to wonder how much would be left from the hay by the next spring when temps are back up.

A thought, I have had as well. Usually when I spread manure (once a year), it still greens things up considerably. No doubt though, when you bring hay in, you bring nutrients as well. Weed seeds to BTW.

 

[Dave]

The conversion factor for nitrogen from crude protein is 6.25. So if you have hay that has 12% protein. A ton of that hay has 240 pounds of protein. 240 divided by 6.25 is 38.4 pounds of nitrogen per ton. The nitrogen that passes through a cow ends up about half in the form of organic nitrogen and half in the form of ammonia. There is very very little nitrate in fresh cow manure or in the urine, way less than 1%. Nitrate is the water soluble form of nitrogen which can and will leave easily. It is also the form of nitrogen most readily used by the plants. The organic nitrogen isn't going to go anywhere. It takes time and the right conditions for it to mineralize into plant available. The ammonia is the part than can leave but might not. It can convert to ammonium and volatize off into the air. Some of it will. It can convert to nitrate and leach off. It can also be used by the plants. There are way too many variables to guess at how it will act after passing through the cow.