Variable rate N

[CORK]

They say that variable rate lime is the first thing that should be looked at, it can free up P and effect friability.
Unfortunately, the lime spreading technology around here hasn’t moved on much in 40 years.

 

[Hindsight]

Can you check that link please, it’s not working here or the summary one. TIA

Hi both are not links they are the actual pdf copies of reports.

The link is: Both the full and summary reports are included on the webpage under Downloads. I feel sympathy for AHDB staff or more the research institutes staff that the research for farmers to question techniques is there feely available (and do remember this is free to the world despite being paid for by grower levy) Fascinating world we live in. Hey ho.

Automating nitrogen fertiliser management for cereals (Auto-N) | AHDB

ahdb.org.uk

 

[willy]

 

[Hindsight]

Thanks. Good stuff. Will read this afternoon.

Can you check that link please, it’s not working here or the summary one. TIA

You may also be interested in the LEAR N research project which was a sister project. Full report as attachment. Link below

Using farm experience to improve N management for wheat (LearN) | AHDB

Nitrogen requirements of wheat are notoriously variable and difficult to predict.

ahdb.org.uk

 

[Nailbourne]

I’ve used VR Nitrogen for the last 10 years, both liquid and solid, and will continue to do so. Our farm is a mixture of thin chalks and deep brickearths, usually in the same field. I could never sleep easy if I used a flat rate across the 2 soil types and satallite VR seems the best way.
Some platforms are too ‘fussy’, the plans changing rate every few meters which is unnecessary I think. Three or four rates across a field are ample.
In conclusion it’s my belief VR nitrogen does have a place on farms with certain soil mixes. One other lesson I have learnt is that when using VR with liquid fert it’s important to use variable rate nozzles otherwise high rates mean high pressure causing higher scorch risk.

 

[Tom H]

We have been N-sensor since 2004. In OSR it's a given when used in "absolute mode". Less N more yield. In cereals in the early days it did a good job of evening up fields and without a doubt kept crops standing. About 4-8 years ago I was starting to see less of an effect in cereals and was questioning what was going on. Everything seemed even with very little effect from sensor.

For the past three - four years we started using the "Absolute cereal" algorithm. I'm really starting to like this. We used it over 1200ha of wheat last year. All feed wheat, giving good yields and importantly the average grain protein was 11.5. so pretty much spot on. It was also a lot more variable across the field. Range on total N to fields was 162-240kgs.

What I like about it is takes out the human emotion from it all. It's based on 3 applications. The first on, a big slug 70-100kgs. This is the only time you set a rate, and where you can have an effect on rate if there is economic reasons (price) The next 2x applications. You only tell it a small about of detail, growth stage etc and IT decides how much to put on. Based on knowing How much the N crop and soil (to a point) at a set growth stage.

Last year it picked up where we had wheat after beans (applied less) Wheat after oats (applied more) and where we had used an autumn manure (applied less). Fertile fields etc.

I also use N-tester to help monitor when to apply, again I like it but the weather and workload normal effect it more!

Anything satellite look horrendous in my limited experience. Plenty of good sensors out there but its all about the trials and algorithm behind it. I know use less N because of the sensor, with no drop in yield ( I think). I hope to go lower again this season.

 

[BenAdamsAgri]

All project reports are also present in a concise summary document = which I attach.

But farmers should read the full document. Print it off and read it. As it is full of useful explanations and knowledge and then one gets the full depth of the project, rather than the headline bullet points. AHDB will be disbanded because farmers do not absorb what research work is commissioned. And thus the checks and balance will be removed. But so be it if that is what farmers want.

Thanks for that

Found this line interesting: 'Also, optimising N fertiliser rates did not substantially reduce variability in achieved yields, implying that the major causes of yield variation were not related to nitrogen.'