SRBeef wrote:I added the bold. In the fall when the temperatures drop and sun is not as strong, corn plants especially take up more N than the plant can convert and nitrates build up in the stalks, especially the lower stalks. This year I let the plants die a bit more thoroughly before grazing and will not let them graze it so close to the ground - don't force them to clean their plate at least early in the fall/winter grazing season. I also did not apply as much N ahead of spring planting as one would normally do for grain production.
As to where the nitrogen goes as the plant dies, I don't really know. I would guess that as the plant breaks down it is used by microbes in converting the biomass to compost/fertilizer. Or a portion of it is released into the air?
Jim
Jim I think you are a bit off in your way of thinking. As a plant matures it takes up less N. Therefore, if your corn reaches physiological maturity before a killing frost or anything slowing or stopping plant growth there would be no problem with nitrates. This is assuming the corn grew adequately during the growing season and high levels of N fertilizer were not used. The answer to where the nitrate goes is that the uptake slows as the plant growth slows unless something disturbs that balance. Not guaranteeing anything but you are likely letting your corn go when they have no problem with nitrate at all. You could take tissue samples and test just to be sure. I always sample any crop being cut for hay or grazed before any of it gets fed. Several farmers lost whole herds of cows by just throwing the cows out on failed wheat fields w/o testing first.
