CORN SILAGE DEVELOPMENT IS MOVING ALONG NICELY
Robb Wock, DPC, Purina Animal Nutrition LLC
62 samples of whole-plan Corn intended for Corn Silage harvest were checked for moisture at the All-American Cooperative/Progressive Ag Center location in Plainview this past Friday, August 21st. These samples came from various areas throughout SE Minnesota, ranging in maturity ranking from 92 days to as much as 113. The result of all samples was an average of 74% moisture, with a range from a low of 70% to a high of 78%. Experience has taught us that it is advisable to add 2-3% moisture to these numbers simply because while we try to implement techniques during sample collection that give us the best chance for field representation, these techniques cannot take the place of harvesting larger areas into 1 collection point such as beef producers & dairymen do when they combine larger portions of plant mass into a wagon or truckload. In other words there is a lot more field variation than we are able to get a handle on or represent with the “smaller” sampling we gather for this type of event. In reality this suggests the overall average is likely closer to 76%, with the range being from 71% to 80%.
So what does this mean as far as future recommendations for harvest? Although “whole-plant-moisture” is considered the golden rule-of-thumb in today’s world when considering the timing of harvest, the real question is always – “what will the DRY-DOWN rate be?” Depending on our weather pattern this can often be the hardest question to answer. But as we consider DRY-DOWN it’s important to note kernel maturation. By in large most of the corn checked for moisture in Plainview on the 21st fell into the “early-dent” range, with a select few showing no denting at all. In the “early-dent” stage grain moisture is generally between 55 & 60%, with whole-plant-moisture at about 75% or so. Interestingly this is the moisture level we found (for an average) on all our samples! During a warmer weather pattern (i.e. high temps in the 80’s) we generally expect DRY-DOWN rates around ¾ point / day and sometimes even higher, whereas cooler patterns are lucky to exhibit ½ point change daily. Even at ½ point / day DRY-DOWN rate the 76% average will convert the 70% in about the next 12 days. Interestingly enough this almost the exact amount of time it takes from “early-dent” to reach “half-dent” as well … approximately 12 days ! So for those of you storing Corn Silage in a BUNKER or PILE I would suggest that you be ready to start harvest in the next 12-14 days, whereas storage in a BAG may be 4-5 days after that, and a SILO following up last at about 7-10 days after that of a bunker. Keep in mind that these are strictly estimates and really depend on the actual weather. It is also important to remember there is a huge amount of data suggesting that once we fall BELOW 62% moisture in the plant being “stored” and fermented that starch-digestibility and energy availability drops significantly – reducing the feedability of Corn Silage and its ability to maintain animal performance.
Keep in mind that All American Co-op and Progressive Ag Center will be holding another Corn Silage “burn-down” event on Tuesday, September 1st in St. Charles. This should turn out to be an excellent time to re-evaluate where things are at, and should allow us an even better opportunity to narrow down the harvest window.