[Steve.B]

Hi All, got a bed for the spuds the soil Ph is high 7.5 plus. Want to reduce this and read that Ammonium Sulphate will do this but will add lots of Nitrogen. Apart from putting lots of well rotten horse manure on the bed is there another way? I have a compost bin full of 2 year old horse manure waiting to go in when this rain stops....IF.
Just wondering if anyone has any other ways to drop the Ph?

[JayG]

7.5 is quite high for spuds - did you use a chemical test kit or a probe? (cheap probes have been found to be pretty unreliable for many on these forums.)

Rotted horse manure won't reduce the pH although it will improve the overall condition of the soil.

Lowering pH is much harder than raising it - moss peat or uncomposted pine needles will help, as will sulphur chips, although the latter will take much longer to have any effect. Ammonium sulphate will work quicker, although as you say you don't want to give your spuds too much nitrogen, even though they are hungry plants overall.

[Trillium]

Pine needles are excellent acidifiers. Over here I can use plain sulphur powder to also lower pH levels. Some folk have even found a water-vinegar solution works.

[heygrow]

I was thinking about the same issue. I have not checked the ph lelvel before, but this year thought I would and it is between 7 and 7.5.
I have always grown new potatoes along side all my other veg in this bed and everything generally grows really well. The spuds, although always producing never give an abudant crop (hence the check). If I increase the acidity in the area that intend to plant the spuds will this leach over and affect the soil around in the rest of the bed, as I think the 7 to 7.5 is probably ideal for everything else (peas, beans, parsnips etc)?

[Steve.B]

Jay G, yes chemical test kit.

[JayG]

Soil pH for growing spuds isn't something which has been discussed much here, so it's a reasonable assumption that most people never even think about it unless it turns out their spuds are all scabby so they have to investigate and try to do something about it......

As far as lowering the pH of one bed affecting an adjacent one, I don't think that's an issue, and when it comes to rotating crops you will probably find that the lime content of your soil will have undone most if not all of your pH-lowering work by the following year anyway. 

[Totty]

I would get hold of a bale of spaghnum moss peat and line a trench with it.
The top exhibition growers all use a mix based on moss peat so you can be sure the taytos will thrive.

Totty

[diospyros]

As an alternative to mined sphagnum peat which destroys precious wildlife habitats, you can buy peat which has been reclaimed from the filters of reservoirs.  I believe there are also products based on composted bracken which have a suitably low pH.

[heygrow]

Does anyone know if seaweed would lower the ph?
I know that jersey potatoes are grown in that.

[Trillium]

I haven't found anything to suggest it moves pH one way or another, only that it's a great soil conditioner.

INFO

[syks grower]

Try looking up sulphur chips they lower the PH