The Agronomists, Ep 28: Christine O’Reilly and Peter Johnson on supercharging forage crops

(Debra Murphy/RealAgriculture)

After a week away, we’re glad to be back! This episode of The Agronomists focuses on something we don’t always talk about: forage!

Host Lyndsey Smith is joined by Christine O’Reilly, forage specialist with Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), and Peter Johnson’s alter ego: Peter “Wheatgrass” Johnson.

Catch a new episode of The Agronomists every Monday night at 8 pm E!


  • Frost! Oh no. Damage shouldn’t show up for a few days, HOWEVER, some things like millet are a warm season grass and do not tolerate frost well. Depends if the growing point is still below the ground
  • Magnesium deficiencies showing up in wheat and some grasses. Tissue samples are coming back low-magnesium.
  • There’s a lot of cation interactions when its a wet year (calcium, magnesium, et al)
  • There’s a lot of fertilizer moving onto hay and pasture fields this year.
  • When is the best time to put on fertilizer? 2nd or 3rd year alfalfa mix, do I put it on before, or after first cut? If I’m only going to apply fertilizer once, when is it?
  • The best bang for your buck will be to get that potash on the field before the fall rest period. Increases winter hardiness
  • The nitrogen needs to go on for first cut, if you want the most production and have grasses in the mix

CLIP 1: Establishing Alfalfa — The Pros and Cons of a Nurse Crop

  • Let’s just move on from nurse crops, please
  • Especially when it’s dry, the nurse crop is too competitive
  • There are better options for emergency forage
  • Type of manure and stage of forage — when am I applying?
  • Stay pretty shallow if you are injecting
  • Once those plants start to regrow — that trample damage will be set back compared to the rest of the field. Keeps things more even if you can get in there in less than a few days
  • Dry manure — multiple trips over the field, the best time to do that is in the fall. Look at that compost as the slow release nitrogen
  • Any time you talk about dry manure, you don’t want any Johnes coming into the situation
  • You have to do a super job of spread pattern
  • The manure itself…would it feed the corn crop in the same year? You have to ask: what’s the carbon to nitrogen ratio? How much straw is in it?
  • If you have a carbon to nitrogen ratio that’s over 30:1, then it will actually be a negative to the nitrogen. The soil bugs will break it down
  • If there’s any nutrient that’s deficient in alfalfa, it’s going to be potassium. It could cause milk fever.
  • How to avoid milk fever? Feed them a diet that’s low in calcium and low in potassium so that the cows body starts to pull calcium out of her bones into her bloodstream. “Prime the pump.”
  • If you’re an agronomist working with a dairy client, the strategy that is encouraged is to tell them to take one field, and set it aside for dry feed and let it draw down K (but put K down on the rest)
  • Leafhoppers is always an issue in alfalfa!
  • See them across a lot of the province, often time they get mistaken for drought. The symptoms look similar. It’s a very common misdiagnosis.
  • Out of our commonly grown field crops, alfalfa isn’t going to show stress as early as the other crops will be.
  • When should we be scouting for leafhoppers? You really want to scout right after first cut, or if you have new direct seeding.
  • The threshold for leafhoppers changes based on size, so this varies.
  • This leafhopper in alfalfa is the same one as in dry beans and potatoes.
  • There are insecticide options, but cutting should be your first choice.

CLIP 2: How to treat forages as a crop of value

  • Supercharging your forage crop!
  • We’re growing soils as we grow our forages, and we’re growing animals as we grow our forages
  • Ruminants don’t come with yield monitors… too bad
  • We need to make decisions based on our grazing management with data. But seriously all, grazing management is huge.
  • Hay crops and forage crops are huge feeders, but don’t forget about the sulphur
  • Making sure that we fertilize appropriately is important. Animal health is important, but we need to make sure the plants are getting what they need, too.
  • Some producers aren’t paying attention to fertility as they maybe should be.
  • A forage crop can be a pretty amazing feed producer, but you’ve got to manage it.
  • If you go through the financial data, on average feed accounts for about 60 per cent of many farms bill. A well managed forage crop pays for itself.
  • Management — we have to get better. Even on one cut wonders!

Have suggestions for another episode of The Agronomists? Send an email to [email protected].

Wake up with RealAgriculture

Subscribe to our daily newsletters to keep you up-to-date with our latest coverage every morning.

Wake up with RealAgriculture