Potato fertiliser recs.

[Fubar]

Been working out the fert requiremants for a crop of second early potatoes.
My soil tests are showing index 2.4s for p and k and I'm applying 30 t per ha fym.
I've had recs from my agronomist and a fert guy.
I usually try and keep things simple and will be using 14 14 21.
Some ground is rented for the spud crop only so I'll get no residual benefit. On my own ground I don't mind going over the top with rates.
One guy is recommending 1250 kg per ha plus 200 kg of potash plus.
The other guy is adament that 850 kg is more than enough.
I will also top up with some straight N.
So who is right?
They are both supposed to be experts.
But only one of them sells fert.

 

[chipchap]

Optimum rate depends on rainfall, or do you have irrigation?
Last year over the top N rates paid a bonus, where I used broiler litter the crops were superior in yield terms.
Personally in my area I would go with the higher rates. Perhaps do your own sums usingRB209. Different varieties need different amounts too.

 

[Bogweevil]

Difficult to say without knowing cropping history, soil type, cultivar and rainfall amongst other parameters.

I use Online Toolbox Fertiliser Calculator http://potatofertiliser.adas.co.uk/ and have done for a while - it is free after all - so an easy way to check on your advisers and ask them the right questions?.

Making many assumptions which will probably be incorrect so this is not in any way, shape, form or nature a recommendation for your particular needs, requirements for growers with conditions similar to yours might very roughly be in the order of:

Please, let us know what your advisers make of this? I trust they are FACTS qualified.