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N Sensor

Discussion in 'Cropping' started by Banana Bar, Nov 30, 2018.

  1. Banana Bar

    Banana Bar Member

    Location:
    Bury St Edmunds
    Is anyone using an N sensor? How long have you had it? Anyone stopped using one? Do they work and are they worth the investment?

    BB
     
  2. Andrew K

    Andrew K Member

    Location:
    Essex
    Used to run blue type, but considered it too expensive and restrictive in use, maybe the white version is better. Would look towards imaging if I did VRA N again I think.
     
  3. Brisel

    Brisel Member

    Location:
    Dorset
    Sorry, I can't help. We had one but the sprayer it was going to be used on tipped over & it never got used, so went back to Precision Decisions. I split the N up between solid & liquid so went to SOYL for satellite based shape files instead
     
    willy likes this.
  4. Tom H

    Tom H Member

    Location:
    Vale of Belvoir
    Yes, had one since 2004. Now have two white once. Do what they say on the tin, excellent on OSR. In my mind you have a N-sensor over everything else, because of the algorithms behind it - using the decades of Yara's trials.
     
    Mdt and ollie989898 like this.
  5. Tom H

    Tom H Member

    Location:
    Vale of Belvoir
    I personally don't like satellite as it stands today. Too many shading issues and not real time.
     
    Mdt and ollie989898 like this.
  6. Brisel

    Brisel Member

    Location:
    Dorset
    I take your point about shading - do you mean cloud cover or a better side view of the crop a few feet either side of the tractor?

    How do fertiliser logistics work with an N Sensor? Do you work on creating the ideal canopy so over order on fertiliser just in case then hope to reduce the doses in the field? How do you calibrate the dose rate? Excuse the questions - I'm genuinely interested in how it works.
     
  7. Mounty

    Mounty Member

    Location:
    Suffolk
    With the Isaria (front mounted sensor) we advise scanning a decent canopy at this time of year so the sensor can measure the potential of the crop. If you scan at same time as first application after a harsh winter or several frosts the canopy will be reduced and suggest less potential.
     
    ollie989898, Brisel and Andrew K like this.
  8. fudge

    fudge Member

    Isn’t the problem with any scanning method the huge range of potential yield from any given canopy? Can this process ever be more precise than an experienced grower/agronomist making an assessment of the crop? I can see the point of altering applications by soil type, but surely that can be done from soil maps?
     
    Hindsight and Brisel like this.
  9. Brisel

    Brisel Member

    Location:
    Dorset
    Surely scanning it now does not give a representative view? There's a lot of winter to go yet & pigeons/rabbits will thin a bit. The early spring canopy is what you need to build so that's when you should be taking more measurements. Sure, a thin patch now warrants noting and special treatment but unless you've already written it off so could adjust the N fertiliser order I think it's too early for major judgement.

    Do you find that the better canopy in early winter provides a better prediction of future yield? Extra leaf loss over winter is easily compensated for by the better root mass?
     
  10. Mounty

    Mounty Member

    Location:
    Suffolk
    Your last sentence is what I'm getting at. The scan now shows what the plant is capable of and the rooting system will already be there to produce that canopy. It is also recording biomass to build this info so more green area info will build this knowledge.
    Scanning a pigeon eaten plant in early Feb won't pick up what was already possible by that plant, esp from a biomass point of view, so the earlier scan helps realise the potential and assigns a rate that will push that plant. Been quite successful in German trials.
     
    CORK and Brisel like this.
  11. Tom H

    Tom H Member

    Location:
    Vale of Belvoir
    Shading comes from either cloud cover. Or when a "photo" is taken in low sun and there is either a wood or large hedge casting a large shadow.

    In OSR (coming in straw crops) "absolute" mode does all the work, you tell it some basic facts, growth stage etc and it applies what It thinks the crop needs. Based on GAI and algorithms.

    In white straw crops at the moment, you decide the intended rate for the field and it works either side of it giving the same average across the field. This was fine 10 years ago but I feel the next stage (Absolute) is the future. Why should I tell it the rate? I'm basing it on emotion, historic practises and bad science linked to legislation. Let it look at the crop and what's in the soil via the crop and make the total decision.

    Absolute mode in OSR I'm using less N to get more yield. OSR is easier to make this work on though ,as N response and performance goes hand in hand with GAI. Wheat for example is more difficult.
     
    Mdt, Centre and ollie989898 like this.
  12. Mdt

    Mdt Member

    Been using the n-sensor now for 13 years and it certainly works. Like Tom h has said in absolute mode on osr its brilliant. It's still good cereals but relies on us for inputs but still works well and certainly see the benefits.
     
    Tom H likes this.
  13. Mounty

    Mounty Member

    Location:
    Suffolk
    Is there 1 point and 2 point mode on the N sensors?
     
  14. Clive

    Clive Staff Member

    Location:
    Lichfield
    Ran one many years ago when they first came out, the passive sensor is very restrictive in spreading hours, active is better. However there are much better ways to do vra N now - SAR is a better approach re agronomy model and not cloud affected which is what we do now
     
    Last edited: Dec 8, 2018
  15. CORK

    CORK Member

    Location:
    East Cork, Ireland
    Pardon my ignorance Clive but what is SAR?
     
    MNBVCXZ likes this.
  16. Clive

    Clive Staff Member

    Location:
    Lichfield
    Satellite radar images - basically a measure of total crop biomass form space. Not cloud cover effected as its radar so reliable regular images.

    Think of NDVI (N sensor or most sat or drone based N systems) as 2d and SAR as 3d images

    The agronomy / application models are "absolute" for OSR and wheat and I believe other crops will follow soon. Used it for first time last year and rate it higher than my experience of sensors so far
     
    CORK likes this.
  17. Mounty

    Mounty Member

    Location:
    Suffolk
    SAR supposed to be a lot better than the alternative imagery although some SAR images have been effected by cloud cover this year so not bullet proof for reliability.
     
  18. Clive

    Clive Staff Member

    Location:
    Lichfield
    How can cloud effect a radar ?
     
  19. Mounty

    Mounty Member

    Location:
    Suffolk
    I don't know but I've seen the images and it did!
     
  20. I guess that the water droplets in the cloud absorb the water signal. Satellite tv suffers from this, but it all depends on wavelengths used.
     

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