Home Discussion Forum Nutrient Management N Management in Winter Wheat Following Alfalfa

This topic contains 5 replies, has 4 voices, and was last updated by Profile photo of Zach Sutter Zach Sutter 2 years, 5 months ago.

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  • #863
    Profile photo of Zach Sutter
    Zach Sutter
    Participant

    I’d like to get some different perspectives on nitrogen management for winter wheat following alfalfa.  I’m an agronomist working in Northeast Wisconsin (Kewaunee County).  No-tilling winter wheat into alfalfa is a practice that is increasing in popularity.

    Even when the minimum credit (90 lb) is taken in SnapPlus, no additional nitrogen is allowed.  From what I’ve heard from farmers and other consultants, simply relying on the alfalfa credit for N is not adequate.  The studies I’ve been able to find support this.  I would like more guidance on appropriate nitrogen management for this practice.

  • #878
    Profile photo of Amber Radatz
    Amber Radatz
    Participant

    When are you killing the alfalfa/no tilling the wheat into it? Is there a seasonality issue with when wheat wants the nitrogen compared to when alfalfa is releasing it?

  • #879
    Profile photo of Zach Sutter
    Zach Sutter
    Participant

    Good question.  I’m guessing that most guys are taking third crop, and then letting it regrow enough to spray off.

    It think that seasonality is the key issue here.  From what I’ve heard, the wheat struggles because there is not available N during tillering.

     

  • #880
    Profile photo of Matt Ruark
    Matt Ruark
    Participant

    I found some data from 1998, where they planted winter wheat after alfalfa. This study was at Arlington, WI and appears to have only been conducted this one year. Under no-till conditions, and no N applied in the fall, there was a yield bump with given 20 lb/ac of N in spring. But no yield gain beyond that. There is some data from Spooner as well, but I don’t have good details. I’m seeing if I can track down the details and actual data.

    Your main issue is that the N from the alfalfa isn’t available early enough in the spring when the wheat takes off. That could be true. Especially if your soils are heavy clay. How much N then do you apply to winter wheat?

    Since wheat tends to do poorly when given too much N (i.e. lodging) there is not real incentive for an over application, so in a sense, if you feel you need to give it 20-40 lb-N/ac and you’re not seeing lodging at all, then you’re probably in justified. But none of what I’m saying here is going to help you with your SNAP Plus issue. I’ll work with the Laura Ward Good and show her this data.

    • #884
      Profile photo of Zach Sutter
      Zach Sutter
      Participant

      Thanks Matt! There are a variety of approaches taken around this area.  Some consultants are recommending 60 lb N.  Others say the right answer is 50% of recommended is the right answer.  I haven’t seen enough growing seasons to personally have a strong opinion.  I’m going to have to make a point this summer to keep an eye on these fields.

      I’d say that there is a need for more research on the topic.  For lack of strong research, there are a variety of approaches being taken.  I’d like to figure out how to make this work the best. From a N management perspective, wheat after alfalfa just isn’t a good rotation.  From a soil conservation/health perspective, I love it.  Due to our heavy clay soils, no-till has been slow to catch on around here.  Guys are, however, pretty comfortable with no-tilling wheat.  I really like Tom’s suggestion below.  Following the wheat with SS strikes me as a good way to use up that N at a time when it is available.  I’d like to get some manure out there after the wheat comes of, too (maybe 5,000-10,000 gallons??).

  • #883
    Profile photo of Tom Novak
    Tom Novak
    Participant

    The workaround I’ve been using with my clients is to follow up the wheat with sorghum sudan.  They can use the feed and it acts as a sponge soaking up the extra N from the alfalfa.  Generally we will stream on 45 units of N early to help tillering if needed but also to get some N out before mineralization kicks in.  I’ve always thought we have been a little short due seasonal unavailability.  Down here the S/S has to be planted by Aug 5th to get a good crop – not sure if that timing works up in the NE?

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