Fert tray test variations

[jh.]

What sort of differences do folk see between test tubes .

Made up a kit for testing a Kuhn axis 40.1 m-emc-w . I am testing using the single pass method mostly but have had same results with full 3 run test.

Sometimes the results all look nice and even . Others the machine is showing stepped results . I place trays in 4th 3m drill width centre so should be an accurate half way point for overlap zones ,24m trams. Try and test on levelest part of field although no always ideal but hills need spread too .

Is this just something that can happen with full electric control metering? . Drop points and flow all done through box so no room for operator error and tests can be over same fert load with no other changes and still throw these occasional stepped variations .

Only thing I am doing differently from instruction manual is testing at working speed rather than the 3-4kph manual says . I give it plenty time to get up to speed so the machine is not still adjusting and drive well past trays before switching off . Was helping other operator test some yesterday and can confirm fert wasn't still hitting trays at off point . Vanes all look good with no marks , although full auto self sets shutter opening I manually checked opening at 85 opening using a lower link pin and both same . Haven't checked drop point with a string method as in manual but both always correct on scale to box setting.

Had got narrower test tubes as my first set seemed too wide and shaking result could change levels. A few grains of soil seem to end up in tests , off tray bottoms I doubt

The sort of differences I am seeing might be acceptable but there is nothing I can see that we can change anyway as all done through control box . Seems a bit rough though to just average out the overlaps and hope it's ok

Going to start double checking centres with a measure but can't see them being far out , even if trams are not a true 24m the drill centre will still be consistent enough surely and we're testing drop point to spread evenly over our tram spacing. Only other thing might be forward speed . Perhaps at 10-11kph the spreader bounces about a bit .

Any ideas or acceptable ?

 

[jh.]

Should add it does throw up metering fault codes quite a bit. Always the same 2 codes but clear them and works away again fine . Have spread with rear window open to listen and watched shutter opening on box but just beeps and shuts off randomly . Have noticed seems worse towards end of day and adjusting drop point from one extreme to another seems to help for a while , like it's a build up of residue

 

[Clive]

The day I started doing tray tests was the first day of our conversion to liquid

If you want consistently even application it’s only possible with liquid

 

[Dman2]

Wheres that drone pic i have of our neighbours field after going round with a blocked nozzle with liquid fert

 

[KB6930]

Are your trays deep enough ? My boxes are around 7 inches deep with a 3 inch grid so no fert gets out again only observation I can make

 

[jh.]

Are your trays deep enough ? My boxes are around 7 inches deep with a 3 inch grid so no fert gets out again only observation I can make

Definitely no where near 7" deep . They have catch compartments. All it said in manual was make sure mounting height is above top edge of trays for test

 

[Chae1]

I'm just perhaps lucky. But have run a kuhn axis 30.1 for 12 years now. Never tray tested and never stripped anything badly. Would have about 600 acres of spring barley 70% of N on in one hit and about 250 acres of silage. Second cut gets it all in one hit. Have just always used decent quality fert. Have spread urea too though.

Ignorance is bliss.

Wait for it though. Probably all be stripped this year after saying this.

 

[Phil P]

Anyone know where to get a decent set of trays with dividers that don’t cost the earth!

I’m just using flat trays (about 7” deep) but never know if some fert is bouncing out or if they’re a bit to tall and two much is hitting the side of the trays especially on the ones between the tramlines.
Not had any stripping issues but I’m a little ocd about these things

 

[eagleye]

could use egg boxes in the trays to "soften" the bounce or the other option would be soft net over boxes which is what i used to do.

 

[Case290]

Are you weighing the test tubes aswell . Best we got when we tray tested was 7% variation. Neighbour uses liquid I don't think I could cope with all the crop scorch .

 

[Phil P]

could use egg boxes in the trays to "soften" the bounce or the other option would be soft net over boxes which is what i used to do.

Could be an idea but think it may make it a little tricky emptying the trays having to lift everything out and not lose some fert in the process. Like the idea of the lift out plastic dividers then tip the tray.
I can find the proper trays online but it’s about £400 for 8! £50 for a plast tray just seems a bit steep to me. Or am I just tight

 

[Case290]

A bit steep . Should be £50 for 8

 

[KB6930]

I started tray testing how the book said at slow speed but found it worked better at normal spreading speed as the spread pattern fairly changed with the axis I had when I went faster

It actually looks like the results I can get on a windy day when it's heavier on one side

 

[jh.]

I started tray testing how the book said at slow speed but found it worked better at normal spreading speed as the spread pattern fairly changed with the axis I had when I went faster

It actually looks like the results I can get on a windy day when it's heavier on one side

I bet your right now that I think about it. When I tested with other chap there was a very slight wind. Nowhere near enough to stop me spraying or anything but bet it's been enough to change the flight of the granules

 

[KB6930]

I'd say it would have to be a fair wind to do that only way to check that would be turned round and run over them in the opposite direction and and if the results were the same but on the opposite side of the spreader that would be wind if not it's something else

 

[Speedstar]

To tray test it right do you not have to have tray's over the full width & do 3 runs with trays across all 3 at the same time, this is how KRM do it at there test place

 

[Jim75]

Think I’d want a few more trays than you have to get a better picture. Chap that came to be would have 40-50 laid out

 

[KB6930]

To tray test it right do you not have to have tray's over the full width & do 3 runs with trays across all 3 at the same time, this is how KRM do it at there test place

In perfect conditions ie in a shed yes they all do it that way

But that's Kuhn's quick way of doing it

When you see stripped fields where is the stripping it's either heavy behind the tractor and light halfway between or the other way round so if you check these points and get them level it (should) !!! work out right

I was fairly dubious about it to start with but it works most of the time I did a job for someone putting 500 kgs/hec on in 1 go on his silage ground tested with this method and it's looking well so far but there's still time yet

 

[Bobthebuilder]

Better off just paying someone with all the kit to come and do a full width tray test every few years if your worried about spread patterns

 

[Phil P]

Better off just paying someone with all the kit to come and do a full width tray test every few years if your worried about spread patterns

Trouble is that you may be spreading 5 or 6 different products such as- P, K, N, N+so3 blends etc and the grade can change from one year to the next which will alter the spread pattern, especially at 24m and up.
We put the first bag of everything over the trays even if it’s supposed to the same stuff as last year and it’s surprising how much some can change!