Fair pricing of drought-stressed forage can be a challenge when harvest costs are higher per ton along with lower yields and reduced energy values due to drought.
Under normal conditions, grain content in a field is about 52 percent of the total biomass. So, when droughty corn fields are earless, the University of Nebraska-Lincoln’s rule of thumb of multiplying the corn grain value per bushel times 7.65 to equal the forage value per ton might need adjustment. For example, if the dry matter is only 30 percent versus the standard 35 percent and field grain content is 40 percent versus the normal 52 percent, then the fair multiplier tonnage price would be five times the grain price instead of 7.65.
An alternative pricing method might be using hay values adjusted for moisture. However, drought many times drives hay prices higher than comparative silage prices. So, the normal rule of thumb, 1 ton of corn silage substituting for one-third the price of alfalfa hay per ton, may also overvalue droughty forage.
The bottom line is that droughty crops have less total digestible nutrients (TDN) than normal forage, so “rule-of-thumb pricing” should be slightly adjusted. Actual field sample nutrient content testing (regarding standing forage for grazing, greenchop or silage) is the fairest method for both the buyer and seller.
For example, if we use 72 percent TDN as normal for corn silage, then a droughty 60 percent TDN crop adjustment factor would equal 0.83 (60 divided by 72), or about 17 percent less value. Buyers bear the risk of overestimating the value of drought-stressed corn, which often has wetter content and less value than normal corn harvests.
Further value pricing might be improved by using free silage valuing spreadsheets on the websites for Nebraska Extension, Iowa State University or South Dakota State University. — Todd Whitney, Nebraska Extension educator
