|
Faunsdale, AL | There is no reason to test the stalk pieces alone. Sounds more like the procedure for a residual N test on corn combined for grain than a nitrate test on forage.
Your forage may be fine by the time you chop it and mix with all the leaves or the cattle graze mostly the leaves and upper portions of the stem. If you have corn with ears, the ear portion can dilute a lot of nitrate since ear weight is usually equal or greater to the stalk weight in good corn. If no ears or sorghum, sudan hybrids etc, you typically won't have as much to dilute the stalk portion, but the levels of the whole plant mixed will almost certainly be a lot lower than the part you had tested.
To answer your question, grazing exposes the cattle to the full undiluted/uncontrolled consumption of the forage and the nitrate is 100% available if they eat it. Only hope is they eat more leaves than stalks and more upper stalks than lower etc. It is possible that they would be OK if you didn't let them clean the stalks up, filled them up on dry, low nitrate hay before turning them out on it, limited grazing time every day etc.
Greenchopping ensures that the stalks will be mixed throughout the forage, so no chance of leaving that high nitrate portion behind unless you cut 2' high. But you do get the high nitrate evenly diluted throughout the whole mass of chopped forage. As with grazing, the nitrate is 100% available to the cattle.
Cutting for hay, nitrate is not volatile and persists in the dry hay, probably even more toxic since cattle may consume more drymatter as hay than as extremely wet fresh forage by grazing or greenchop.
Silage, if properly fermented, can cut the level of nitrate by around half AND offers the opportunity to leave a lot of the nitrate in the field by cutting higher than normal.
You need to retest the forage somehow since I doubt you are planning on feeding only the 1 to 2' section of the stalks. Then you can make an educated decision about how to proceed.
| |
|
Midwest nitrate test
