Don’t Leave Yield In The Field

As we make our way through harvest across our footprint, we’re urging folks to check for harvest loss in both corn and soybeans. Check for grain that does not get into the combine as well as losses caused by machinery.

To check for harvest loss, combine a strip in your field then stop, back up, shut off the machine and check in front and behind to see if crops have been left behind. Field losses should be one bushel per acre or less in normal conditions.

A one-bushel loss is equivalent to:

  • Two corn kernels per square foot
  • One ear per 100 feet in 30-inch rows
  • Four soybeans per square foot

Test weight

While high test weight is often discussed as an important trait for corn, it can be misunderstood. Test weight is measured based on the volume of a bushel which measures 1.244 cubic feet.  The official measurement of test weight historically used a one-quart volume which was filled with grain, leveled off and measured with a calibrated scale which reads test weight in pounds per bushel. One bushel equals 32 quarts or 4 pecks, so the weight of the one-quart measure multiplied by 32 equals the weight of one bushel of grain.

Grain test weight normally increases as grain dries. One of the reasons this happens is that drier grain packs more densely into the test weight measurement apparatus. Since corn kernel dry matter is denser than water, the bulk density (weight per volume) of the kernels increases as water is removed.

Common factors affecting test weight in corn are grain moisture at harvest, drought stress, late-season foliar diseases, below normal temperatures during late grain fill, late planting and hybrid genetics. An early frost that stops normal grain fill can have a large impact on test weight and ear rots can also affect test weight, but are not usually uniform across a field. 

Stay safe this harvest season, and let us know if you have any questions or concerns.

Terry, Dan, Rod and Denny