What is the percentage of Nitrogen available through mineralization each year?

Question

The available answers are 2, 15, 50 and 78. I know that is can't be 50 and 78. I can't find the exact figure between 2 and 15.

Answer 1

The answer is going to vary depending on the crops grown before, cover crops, rotation of crops etc, but generally you could expect the N through mineralization to be closer to 15%.

Answer 2

The significant question would be whether we can get the percentage up to 60% without yield reduction.

Tests at Ottawa suggest this is possible under well controlled parameters. But that was with heavy manure applications.

Answer 3

I don't know the answer and I find that such a generalized question is not very useful given the varied soil types and conditions found on the planet. I do know that nitrogen pollution of the ground water is a huge issue and has required legislation in many places to control the amount added to a certain area of land (those nitrogen products are very soluble in all forms). Considering the nitrogen cycle of the soil which is very dynamic and the dependence of plants on that nitrogen cycle, I would have to say that 2% would be too low as a generalization given the amount of gaseous nitrogen in the air and components in the soil found in so many intermediate stages. 15% seems more logical giving the dynamics of soils with respect to this single element and it's cycle. The higher numbers as you say do not seem right or our need for specific levels of the element would be reflected in our fertilizer formulations. They are not.

Answer 4

8