Thursday, September 11, 2014
Stalk Nitrate Test
By Randy Darr, President of Soilright Consulting, Inc.
I spent Tuesday walking corn fields in the area taking stalk samples. After the crop is finished growing, it reaches a point commonly known as “black layer.” After black layer stalk samples can be taken to find the amount of nitrogen still in the plant. This is helpful in knowing if more nitrogen was applied than needed. We also like to take soil nitrogen samples at this time to see how much is left in the soil. Just because it isn’t in the plant, we shouldn’t assume that nitrogen isn’t in the soil.
If the plant prematurely dies there will be more nitrogen left in the soil than what we will find in the plant. I have seen quite a bit of leaf disease in plants. Stalk quality is really deteriorating faster than normal. I suspect that there may be more nitrogen left in the soil than in the plant…..but maybe not. That’s why we take samples.