Proper harvest management is critical for producing high quality corn silage. Below are a few quick tips to consider when harvesting your corn silage.

Tips #1: Check the whole plant moisture

  • Ideal whole plant moisture for corn silage harvest is 62-68% moisture (38-32% dry matter) (for horizonal bunker storage)
  • 62-68% moisture range can correlate with ½ to ¾ milk line progression, but doing a harvest sample is the best way to check whole plant moisture before cutting an entire field
  • Different storage methods will require different ideal whole plant moistures for optimal ensiling conditions
  • Approximate corn silage dry-down rate: 0.5%/day
  • Environmental conditions and hybrid characteristics can influence the dry down rate

Tip #2: Get the right chop length

  • Target a theoretical length of cut (TLC) (aka target chop length) of 1/2 to 3/4”
  • Silage chopped at the TLC of 1/2 to 3/4” will pack more firmly and result in increased palatability
  • Course particles will reduce packing efficiency and can cause silage to spoil due to poor fermentation
  • Particles cut too fine can reduce palatability and can result in a less effective roughage source

Tip #3: Use a bacterial inoculant

  • The ensiling process relies on bacteria to produce lactic acid to “pickle” the silage and prevent the silage from spoiling and minimize loss
  • Lactic acid-producing bacteria occur naturally on the chopped silage. Other bacteria are also present which are competing for the resources the lactic acid-producing bacteria require to “pickle” the chopped silage
  • These bacteria work in anaerobic conditions which is why getting the right chop length and good packing is critical
  • Lactic acid-producing bacterial inoculants are alive and inactive until rehydrated with moisture from the chopped silage (one of numerous critical reasons for ideal harvest moistures) and can greatly improve ensiling process
  • Depending on the operation, a lactic acid-producing bacteria inoculant may not be necessary but a hetero-fermenting bacteria (L. buchneri) can be used to increase improve bunk face management

Tip #4: Pack the pit properly

  • The purpose of packing the pit is to remove excess oxygen than can inhibit the ensiling process
  • Tractor weight and layer depth is critical for good packing
    • Tractor weight: the fill rate (tons/hour) should not be greater than the weigh of the tractor (lbs) divided by 800
      • Example: if the tractor weights 40,000 lbs, the fill rate should not exceed 50 tons/hour (40,000/ 800 = 50)
    • Layer depth: fresh silage should be packed in 6” layers on the packed bunker to avoid the development of air pockets between layers

Tip #5: Cover the silage pit quickly

  • Use oxygen barrier film and UV resistant plastic to cover the full bunker as quickly as possible
  • Large bunkers can take 1-2 days to fill
  • Covering and sealing the bunker reduces dry matter loss and spoilage risk
  • Once covered, weigh down the plastic barrier – tires are commonly used
Sara Meidlinger Market Agronomist Lead - Alberta & Western Saskatchewan