Corn in Ontario is finally drying down, just as the cold, wet, fall weather kicks into gear this week. But, hey, it’s not snow (sorry, Western Canada).

In this week’s Wheat Pete’s Word, host Peter Johnson is answering plenty of your questions on soil fertility, fertilizer rates, and residue management considerations in conjunction with fertility for the year ahead.

Have a question you’d like Johnson to address or some yield results to send in? Disagree with something he’s said? Leave him a message at 1-888-746-3311, send him a tweet (@wheatpete), or email him at [email protected]


  • Corn crop talk: the corn hung around at 29 per cent for so long, and then BOOM all of a sudden, seven to 10 days and the corn has dropped to below 24 per cent. Maybe a husk issue?
  • Lodging risk? Pay attention to stalk integrity! A wet August, a September frost, whatever it was
  • 194 bu/ac corn usually 160 ish. Big number. 21 to 23 per cent moisture. Woot!
  • Soybean report: Late April soybeans, mid 70s
  • Hybrid corn results, nothing under 200 bu/ac — with a question: no yield gain with fertilizer addition? Yield monitor isn’t the best gauge
  • Custom combine operator will cost $11 an acre to turn on the chopping corn head, and that I’ll save money in N next spring. Very little breakdown over the winter. There will be some but not a lot, but they will tie up N and breaking down will tie up MORE N. So, no, you likely won’t save on N. But if you are someone who does tillage — turn on the chopper! It’ll mean you can go faster in the spring.
  • Phosphorus (P): Visual response doesn’t always mean a yield response, for sure. But take it to yield and see where that limit is, plus remember that extra P (on a soil test) will go straight out the tile. All bad from an environmental stand point. On high soil test, add a little, but less than crop removal, for sure. Draw down that soil P! (Check out the last Ontario Diagnostic Day on this).
  • Variable rate push: retailer is pushing for variable rate for some inputs, like lime. Does it pay? How good are your maps, first off. That’s where you have to start. Responsiveness to the input you’re putting on will play a big role.
  • Potassium (K): do you put it on in the fall? Put it where it fits in rotation (ahead of soybeans)
  • Straw in your soil sample? What’s the impact? At one per cent it increased the P a little, but the K level by 229 per cent! Don’t get straw in the sample.


2 thoughts on “Wheat Pete’s Word, Oct 21: Damp husks, variable rate lime, chopping stalks, and too much phos

  1. Pete- At the very end of episode 43, you say to not get straw in the soil sample because it will skew the potassium reading too much.
    Won’t that potassium “be there” or are you worried about the amount of time for it to breakdown or ????
    SW Alberta

    1. From Peter:
      Hey Wade:
      Great question/thought process. The straw increases the soil test K because it is easily leached from the residue during the extraction process in the lab. In a field situation, the potassium will leach out over the winter, and most of it will become tied up in the soil matrix. Once that happens, it will be available, but slowly, over time. This is even more critical with phosphorus. The straw increased the soil test P as well, not quite as much as K, but P is rapidly immobilized in soil and then is very, very slowly available.

      High soil test results from residue in the sample will make you think you don’t need fertilizer, when actually you do. Residue in the sample will have much less impact if soil sampling in the spring, after leaching of the residue has occurred. But soil samples are taken in the fall should have the residue moved before the probe goes in the ground.

      Hope this helps!

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