2018 Corn Silage Harvest Might Be Like None Other

Simply getting corn silage our of fields could prove challenging for farmers in some areas of the Upper Midwest. Feed quality will be the next challenge. ( Farm Journal, Inc. )

From drought in the western Corn Belt to floods in the Midwest, this year’s corn silage harvest could prove to be like none other.

Drought in areas of Missouri and the western corn belt are seeing corn stalks shrivel and die, leading to concerns over high nitrate levels. At the same time, some corn fields Wisconsin, Minnesota, Iowa, Illinois and Michigan have been turned into nothing less than swamps with rainfall ranging from 10” to 15” in the past couple of weeks. It all happened as corn was approaching maturity and forage choppers were being greased up to start silage harvest.

If you’re in areas of heavy rainfall, simply getting the crop out could prove challenging. And if you can get into fields, feed quality becomes the next big concern.

John Goeser, Animal Nutrition and R&I Director, at Rock River Laboratory, Inc. in Watertown, Wis., has gleaned advice from a number of University and industry nutrition and agronomy experts from across the country on how to handle rain-deluged crops. Here’s his summary:

Flooded corn?

  • Walk fields, monitor maturity and harvest at appropriate moisture / kernel maturity
  • These fields will likely have different epiphytic bacterial populations
    • Mud/soil contamination and increased potential for odd ferments
      • Potentially increase the buffering capacity (harder to ferment) and bring more contaminants
    • Limin's group published a paper (attached) showing flooded corn can ferment "OK"
    • Do everything you can to promote an aggressive ferment
      • Successful / efficient ensiling can help clean some things up
      • Inoculate with lactic acid bacteria and an L buchneri wouldn't be a bad idea either to help it be as "clean" as possible
  • Chop high - mud/silt will be heavier on the bottom
  • Watch for denitrification (plant can't process N any more) and plant death in prior flooded fields - the N is tied up

Tar-spot and heavily (fungi) infected fields / contamination?

  • Tar spot (mold/fungus) is showing up heavily through some of the MW US
    • http://ipcm.wisc.edu/blog/2018/08/tar-spot-on-corn-in-wisconsin/
    • I spent some time with Prof Damon Smith (UW Plant path Prof) yesterday - here are primary concerns:
      • Tar spot is not a known toxin producer but is killing plants off; some fields hit 100%
        • Originates from Central / Latin America
          • Has been combated with hybrid resistance (traditional plant breeding methods)
        • Lots of unknown in the US currently
      • Secondary fungal infections are coming in as plants are dying off / decomposing
        • As Damon put it to me yesterday, these brown leaves are a "pandora's box"
        • Damon's seeing some Fusarium spp molds come in, these are toxin producers
      • Walk fields, monitor infestation and harvest as close to silage DM / kernel maturity as possible
        • Aim for 35% DM
        • Kernels may be lighter test weight but are drying out anyways because plants are dead
        • Watch / take note of hybrids that stayed green or don't seem as heavily infected - consider these in your line up next year
      • Tar spot likely overwinters on residue
      • For next year, Damon and the UW Plant Path team will have some insight on fungicide effectiveness coming out of this season now - stay tuned
  • Other fungal infestation w/wet season
    • Walk fields, monitor kernel maturity!
      • Don't assume wet plants are stagnant for kernel maturation
      • Talking with one consultant in SW WI earlier this week, some folks are seeing "wet plants" but kernels at black layer
    • Plants / kernels will continue to mature through wet / soggy weather

Kernel maturity recognized as beyond ideal (i.e. oh crud, it's 3/4 to black layer) for silage?

  • Kernel maturity and whole-plant moisture have "disconnected" from one another the past few years seemingly
  • If kernels are well beyond 1/2 milk, shorten chop length, this will help get KP done
  • Monitor KP with float test or send to lab - goal is 60% KPS with fresh chopped corn

Chopping down corn or dealing with mudding through fields?

  • If corn snapped and plant is dead - go get it off ASAP
    • Chop against the "grain" to try and pick it up
  • If corn goosenecked and isn't dead - let it go it a bit, it'll likely rebound and try to straighten itself
    • Monitor plant DM and kernel maturity
    • Take it off at right DM/maturity

Inoculant or not?

  • Yes, research backed bugs or acid/preservative on at recommended / heavy rates
  • $1 to $2 / ton equates to 3¢ to 6¢/cow at 20 lb dry matter intake corn silage
    • This investment up front might help us from putting three to five times that into the diet later to mitigate ferment / stability / contamination issues