P and K

[ollie989898]

What improvements in my grass am i going to see by getting P levels up?

Much better response to nitrogen and faster regrowth after cutting/grazing.

Sort your pH first if necessary.

 

[ollie989898]

The college have recommended 375kg/ha of tsp or 500kg/ha of scotphos for the low fields. Im confused, doesnt that give a different amounts of P? @Brisel @neilo

Tsp is £353/t. Scotphos 0.29.5.0 is £208/t +£11/ha spreading.
Its around 90ha i want to do. Can you guys tell which is the best value? Ive got myself in a right mess with my maths

Use the TSP.

 

[Dave6170]

Are they allowing for varying availability between the products?

I know little about either product.

500kg/ha of 0 29.5 0 or 375kg/ha of 0 46 0. I just get in a mess with metric and imperial but if i use units/ac, 3cwt of tsp gives 138 units. 4cwt of scotphos gives 118 units.
So i guess 2.5cwt of tsp gives 115 units which is a closer comparison.

 

[Cab-over Pete]

The college have recommended 375kg/ha of tsp or 500kg/ha of scotphos for the low fields. Im confused, doesnt that give a different amounts of P? @Brisel @neilo

Tsp is £353/t. Scotphos 0.29.5.0 is £208/t +£11/ha spreading.
Its around 90ha i want to do. Can you guys tell which is the best value? Ive got myself in a right mess with my maths

Just get two artic loads of P-grow, bang it on the area at the whatever rate that works out at and test again next year.

It’s the best value P by a long way. Not the cheapest per tonne, but good value. It’ll spread 12m no bother and work in the soil quickly. TSP won’t do any good until about the next lunar eclipse.

 

[Dave6170]

Just get two artic loads of P-grow, bang it on the area at the whatever rate that works out at and test again next year.

It’s the best value P by a long way. Not the cheapest per tonne, but good value. It’ll spread 12m no bother and work in the soil quickly. TSP won’t do any good until about the next lunar eclipse.

Is that any use for grassland? I probably wont be able to get it on untill spring time. Then there will be animals everywhere.
Why do you say that about tsp? I ve no experience with it

 

[Cab-over Pete]

It’s quite well known that TSP needs a kind of conversion period in the soil before it becomes available to plants.

It’s not a waste of time or money, but if you need some in a hurry then you need something else.

You can use P-grow on grassland but the manufacturers do advise a grazing closure period. In my experience, most people ignore it, but I’m not advising you to do that.

 

[Brisel]

The college have recommended 375kg/ha of tsp or 500kg/ha of scotphos for the low fields. Im confused, doesnt that give a different amounts of P? @Brisel @neilo

Tsp is £353/t. Scotphos 0.29.5.0 is £208/t +£11/ha spreading.
Its around 90ha i want to do. Can you guys tell which is the best value? Ive got myself in a right mess with my maths

Here’s the metric calculation. 375 kg Tsp gives 172.5 kg of P2O5 at 77p/kg. 500 kg Scotphos gives 145 kg at 72 p/kg not allowing for spreading cost or the bit of K you get.

 

[Dave6170]

Ive ordered powder phosphate. Just putting half the rate on just now and will see what i can afford later. Maybe a top up with tsp.
Thanks for the advice everyone.

 

[Dave6170]

Just a quick update. Put on 400kg/ha of powder phosphate (0.29.0) at the end of march, i dont think it spread all that well, it was extremely fine powder and dry.

Should i just test again next year to see if it has made any difference? Should i see any yield response this year?

 

[ollie989898]

Just a quick update. Put on 400kg/ha of powder phosphate (0.29.0) at the end of march, i dont think it spread all that well, it was extremely fine powder and dry.

Should i just test again next year to see if it has made any difference? Should i see any yield response this year?

You will see a response this year. You can test some of the treated area if you really want but I would focus your attentions on other parcels of land you have no tested or treated yet.

Depending on what you do with the ground this year you may want to consider a modest dressing of something to put back anything you may have removed in a heavy silage cut, for example.

 

[Chae1]

Just a quick update. Put on 400kg/ha of powder phosphate (0.29.0) at the end of march, i dont think it spread all that well, it was extremely fine powder and dry.

Should i just test again next year to see if it has made any difference? Should i see any yield response this year?

Can you get combi cake up your way?

Its basically dried sewage, its really high in P. Pretty sure Sinclairs from ellon were spreading and distributing it. Get soil tested for free too.

 

[Dave6170]

Can you get combi cake up your way?

Its basically dried sewage, its really high in P. Pretty sure Sinclairs from ellon were spreading and distributing it. Get soil tested for free too.

Yeah you can i think but its all sewn up pretty much. Farms near the towns.

 

[Dave6170]

@Brisel i have re tested a few fields again, just out of interest to what the P levels have done. Basically nothing has changed with what i applied last year. Some results have even gone down.

Should i have seen a difference? Have i sampled at the wrong time of year?

I have ordered a load of fibrophos this year.

 

[clemmo]

It takes a long time to raise indices

 

[Brisel]

@Brisel i have re tested a few fields again, just out of interest to what the P levels have done. Basically nothing has changed with what i applied last year. Some results have even gone down.

Should i have seen a difference? Have i sampled at the wrong time of year?

I have ordered a load of fibrophos this year.

What time of year did you test last time? It needs to be roughly the same for a fair comparison. You said you'd put a half rate on. What were you expecting? What rate did you actually use & which product? What did you take off in crop output?

It takes a long time to raise indices

This. You can draw it down for a long time but building it back up also takes a while.

 

[Dave6170]

Tested roughly same time of year.
400kg/ha of 1.29.0 powder. Did that rate because thats how the lorry load fitted the acres i wanted to cover. Sac recommended 750kg/ha of that product to bring it up to M level.

Just wondering should i see a difference at this stage.

Last year the grass growth was amazing but was due to the weather more than anything.

 

[Brisel]

That's 116 kg/ha P2O5 which won't move the indices much. Take a few cuts of grass off the field & you'll have removed a chunk of that.

 

[Dave6170]

This is going to take time and money by looks of it

 

[Brisel]

'fraid so.

 

[Bogweevil]

Think of it as an investment against the eventual depletion of phosphate reserves: