Check Moisture And Nitrates In Corn

Know your numbers for corn silage.

Published on: Aug 20, 2012
Another way to estimate moisture is by squeezing a sample of finely chopped material in your hand as tight as you can for about 90 seconds. If juice squeezes out between your fingers, it's probably 75 to 80%. That was true for the Green sample, and not quite true for the Brown sample. At 70 to 75% moisture, when you open your hand, the ball will hold its shape fairly well and your hand is moist. At 60-70%, when you open your hand the ball will expand slowly with little or no dampness on the hand. At less than 60%, the material will expand and fall and lose its shape.

When corn gets into a normal maturing and drying stage, with normal weather patterns, we'd expect to lose about 0.5% moisture per day. We can expect that to be different with a drought stressed crop with little or no corn in it.

The Brown sample tested at 2070 parts per million of nitrate nitrogen, and the Green sample at 518. The cost of this test was just $9 per sample. These fields had about 120 pounds of nitrogen applied in the spring through preplant, starter and sidedress applications.

Nutrients in these 2 chopped corn samples tested very much like a respectable grass hay silage: 11-12% protein, 27 to 42 ADF (Acid Detergent Fiber), 48-55% NDF (Neutral Detergent Fiber) and 65 to 69% TDN (Total Digestible Nutrients). Starch tested 4 to 6% compared to averaging about 32 to 36% in normal corn silage. University articles suggest that drought-stressed corn silage can have 80 to 100% of the feed value of normal corn silage. A lab feed test can be helpful in determining the value and in deciding how it might be used in rations.

For more information, do a website search for "Minnesota Extension Drought" or "Minnesota Extension Using Drought-Stressed Corn."