Check Moisture And Nitrates In Corn

Know your numbers for corn silage.

Published on: Aug 20, 2012

Earlier this month, University of Minnesota Extension specialist Dan Martens checked on chopped corn moisture in a couple drought-stressed corn fields on non-irrigated sand in the St. Cloud to Clearwater area.

He issued the following report:

The farmer chopped a couple hundred feet into the fields and took a five-gallon pail sample from that. Both fields were around 6 feet tall and had not made any corn yet, and probably wouldn't make much corn. One field looked quite brown from the road. The sample from this field was a mix of pale green and straw colored material, labeled "Brown". The second field had greened up some with recent rain and the sample was a fairly normal green color, labeled "Green."

Check Moisture And Nitrates In Corn
Check Moisture And Nitrates In Corn

The Brown sample tested around 75% moisture with the Koster tester; the Green sample tested about 80%. I took a sample to the feed testing lab in Sauk Rapids because I was curious about nutrient and nitrate content. The lab test showed 75.4% moisture on the Brown sample and 79.7% on the Green sample – basically around 75 and 80%. Based on the samples, both fields were too wet for putting in storage. General recommendations are 60-70% moisture for bags, 65-70% for bunkers and piles, 50-60% for oxygen limiting silos, and 60-65% for upright silos.