Corn Silage Harvest; Making the Best of an Unusual Year

Published on Thu, 08/01/2019 - 11:14am

 Corn Silage Harvest; Making the Best of an Unusual Year.

 By Michael Cox.

 2019 has certainly been a memorable year for corn growers and the outcome of this year’s crop remains unpredictable until the crop is harvested. Unrelenting rains and widespread flooding delayed corn plantings across most of the Midwest. Such was the scale of unplanted acres this May, that the lack of a green canopy across the corn belt was visible from Space; with photos from space stations showing a vast area of brown, unsown land across a typically lush green Midwest. June plantings surprised many in the industry who had predicted a much larger unplanted area than materialized. However, the quality and quantity of much of this late planted crop is yet unknown, as reliable research is unavailable for such late plantings. With a predicted shortage of forage across many States this Fall, sticking to best practice for harvesting will help make the most of this seasons crop.

Maintain delivered bulk
Shrink is an eternal challenge for putting up a silage crop and results in a large economic loss. Shrink of more than 10% of dry matter should ring alarm bells that the current management at harvest time has some issues that need to be rectified. Especially with feed prices expected to tick upwards this Fall, reviewing shrink management can pay big dividends to retaining as much of the harvested tonnage as possible. Most of the shrink management will occur right around harvest time; namely correct chopping, densely packing the corn at around 15lbs per cubic foot and sealing the bunkers as fast as possible. Shrink losses can also increase once the bunkers are opened for feeding. Correct feeding out practices such as taking a small amount off the entire front wall of the bunker will help to reduce excess heating and shrink losses.
Assuming the remainder of the growing season turns favorable, harvest dates may still be at the fringes of typical date ranges. Predicting harvest dates is always a challenge, and nothing beats as much forward planning as possible. Being out in the fields and regularly assessing crop stages can help keep ones on eye in on crop development. Measuring dry matter several times per week using a lab or home testing can reduce the risk of getting caught out with a rapid dry down, as happened many producers in 2018. Milk line movement can offer some insight into what’s happening with the crop, but a full plant dry matter test is the best way to determine what the entire plant moisture levels are, as different parts of the plant will dry down faster than others.
Planting date and silking dates should be recorded as they can serve as a guide to harvest timing. 60 days post silking is usually required by plants to mature properly. Samples should be taken from various parts of the field if there are differences in soil type or the slope of the field; as soil fertility and soil moisture will affect how the plants dry down at different speeds.
Kernel processing can fluctuate throughout the harvesting period too. Keeping a close eye on how well the crop is being processed during each day is important. Rollers may need to be adjusted to maintain an even processing of the crop as the harvest season progresses and crop conditions change.
Mycotoxin levels could be a challenge this year, particularly if wet weather continues throughout the season. Do you need to use an inoculant at harvest time this year? Your local Extension officer can be a good person to discuss these matters with pre-harvest.

Digestibility challenge
NDF digestibility; can we maximize the utilizable quality of the feed as much as possible. Given the possibility of a shortage of forages in many areas this coming winter, it may be tempting to try to gain a little on the tonnage side of a harvest, but this will almost always cause digestibility to suffer. Individual farms will need to pencil out where they can strike a balance between quality and quantity of the harvested crop. Cutting lower will increase the size of the bunker pile, but it may not increase anything positively when it is fed out. Starch content and kernel digestibility will not be affected as much by the weather and growth conditions as the fiber digestibility of the rest of the plant. Rain and irrigation typically reduce NDF digestibility and the pre-tasseling phase of vegetative growth has a major impact on the digestibility of the crop. It remains to be seen if the rains after planting will have a negative impact on the digestibility of the crop.
The 2019 season looked dire for growers for most of this year’s season, but all hope is not yet lost. Perhaps this year more than ever is the year to be as proactive as possible and keep an eagle-eye on the development of the crop in the run-up to harvest time. Pre and post forage analysis of the crop will give clarity and some peace of mind as to what Mother Nature provided for us this year.