AMES, Iowa – The soil fertility tests farmers have used for decades to measure nitrogen levels don’t account for the vast majority of the nitrogen in soils, so Iowa State University scientists helped ...

Add Yahoo as a preferred source to see more of our stories on Google. Organic nitrogen is important for plant growth, but too much of it can cause a range of problems. Over-fertilization, improper ...

With some uncertainty about how much residual nitrogen is in soils, growers are being urged to consider getting fields tested ahead of early fertiliser applications. Hutchinsons fertiliser and crop ...