Silage harvest options for a wet fall
October 3, 2018
BROOKINGS, S.D. – Rains have caused many saturated fields and left some producers concerned that there will be little to no opportunity to harvest silage before corn dries down past desired moisture levels or the first frost.
"This has been a challenging year with heavy spring precipitation and now extensive fall precipitation in some parts of southeastern South Dakota. Remember, all hope is not lost for your forage crop. There is no easy fix to a missed silage cutting, but there are a few options to consider," explained Sara Bauder, SDSU Extension Agronomy Field Specialist.
Why optimum moisture levels matter?
Because creating quality silage is most dependent on harvest plant moisture, ideally, when chopping silage, kernels should be one-third to two-thirds down the milk line and on average, 32-38 percent dry matter.
“This has been a challenging year with heavy spring precipitation and now extensive fall precipitation in some parts of southeastern South Dakota.” Sara Bauder, SDSU Extension agronomy field specialist
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Harvesting at more than 40 percent dry matter reduces digestibility of fiber and starch, and also causes packing issues. More specifically, the optimum silage moisture ranges, depending on storage facility, include the following:
Upright oxygen-limiting silos: 55-60 percent
Upright stave silos: 60-65 percent
Bags: 60-70 percent
Bunkers: 65-70 percent
"In other words, wetter silage tends to work best in bags, bunkers and piles for better packing," Bauder said. "Dryer silage tends to work better in upright silos to minimize seepage."
If corn does dry down before silage can be cut, there are still a few options available for those who want to produce wet feed this year.
Equipment availability and plant moisture should help determine what works best on your operation.
"If precipitation continues, farmers may have to wait until freeze-up to enter some fields," Bauder said.
Chopping dry silage
Although not ideal for optimum feed value and storage, if a producer chooses to chop silage above 40 percent dry matter, there are several considerations to make:
* Reduce chop length to release more plant fluids and improve packing.
* Use a kernel processor to improve digestibility – the more mature the corn the less digestible it becomes.
* Use silage inoculants to improve fermentation. Liquid inoculants may be more effective in dry silage.
* If piling or using bunker silos, use extra heavy tractors for packing and pack no more than six inches at a time.
* Blend wetter feeds with your dry silage like forage sorghum, alfalfa or later-planted green corn.
* Place your wettest forage on the top layer of the pile or horizontal bunker for sealing and weight. Adding water to the top layer of the pile may also help with this.
* Cover tightly with silage plastic and/or oxygen barrier to keep the environment as anaerobic as possible.
"Some producers may choose to add water as they pile or fill silos; however, it takes approximately seven gallons of water for every ton of silage to raise moisture content one point and corn plant material absorbs water quite slowly," Bauder said. "Therefore, a large amount of water would be required at a very fast rate to keep up with most silage harvest processes, making wetting nearly impossible to render major results."
Bauder reminds producers that dry silage can often heat and mold, lowering protein digestibility and energy. "This happens mainly due to oxygen embedded in the silage due to poor packing," she said.
Earlage is defined as ensiled corn grain, cobs, and in some cases, husks and a portion of the stalk depending upon harvest method.
"With an energy content higher than corn silage but lower than corn grain and a similar protein content to corn silage, earlage makes a good alternative," Bauder said.
Ideally moisture content is 35 to 40 percent (60-65 percent dry matter).
A silage chopper with a snapper head can be used.
"Other producers have successfully used combines set to retain a portion of the cob with the grain," Bauder said.
She explained that much like silage, if harvested too wet, seepage may occur; if harvested too dry it will not pack well which causes excessive spoilage.
Things to consider when chopping earlage:
* Make sure that every kernel is cracked and that the cob portions are no larger than a thumbnail to improve pack density and digestibility.
* Consider using a kernel processor to improve digestibility.
* Use inoculants to improve fermentation.
* If piling or using bunker silos, use extra heavy tractors for packing.
* Cover tightly with silage plastic and/or an oxygen barrier to keep the environment as anaerobic as possible.
Baling Corn Residue
Although removing all corn residue off of a field in the late fall is hard on soil health (much like chopping silage), if an operator feels it is their only option, harvesting corn for grain and baling corn residue may be a viable feed option.
"Corn grain and corn stover can be ground and mixed into feed rations as an alternative to feeding corn silage," said Warren Rusche, SDSU Extension Beef Feedlot Management Associate.
Rusche encouraged livestock producers to contact an animal nutritionist for assistance creating a total mixed ration.
"If at all possible, plan on returning manure with or without bedding to these fields to help replace soil organic matter," he said.
This practice can be accomplished successfully, but it requires intensive management and involves livestock health risks if not carefully monitored.
Strip grazing and/or limit feeding are both important parts of grazing corn fields. Swath grazing is sometimes a good alternative to grazing standing corn.
In this process, the producer swaths the standing corn or corn stover and allows mature cattle to graze throughout the winter.
Grain overload or founder is a concern. "If access is not strictly controlled, producers run the risk of severe digestive upset or death due to consuming too much corn at once," Rusche said.
"Again, grazing the entire corn plant requires intensive management. Implementing this strategy should be planned carefully and in most cases is a last resort if all other options to salvage value are not feasible," Rusche said.
Baling the entire plant
Although not recommended, baling standing corn can be accomplished in some cases.
According to Bruce Anderson, University of Nebraska – Lincoln Extension Forge Specialist, whole plant dry matter levels should be at 80 percent-plus when baling.
Stalks should be conditioned or cut with a rotary mower to allow moisture to escape.
Getting stalks dry for baling, keeping bales tight, and avoiding ear molds in this case can be very difficult. If a producer does bale standing corn it is best to feed bales quickly to avoid storage problems.
What to watch for
Flooded corn can contain many contaminants.
"Watch for corn ear molds, stalk molds, and if the plant is quite dirty, soil contaminants," Rusche said.
He explained that preservatives and fermentation do not lower the concentration of these toxins in feed.
"If you have concerns or have seen any of these issues in the field, first consider identifying ear or stalk diseases. Then, contact your crop insurance agent to determine the right procedure," he said.
For more information about harvesting corn as a forage, contact SDSU Extension staff near you. For a complete listing, visit iGrow.org and look under the Field Staff icon.