Hi,I took on a new allotment late last year and the soil was very heavy clay.I dug over it last year and put seeweed on top to breakdown over the winter.This spring I dug over again and manured it before potatoes went in,it was still very heavy.
Potatoes are up and doing ok and I have earthed up twice,I know it will take a few years to get soil right,but im wondering would it be a good/bad idea to put well rotted manure between the ridges?.My thinking was it will help the potatoes and when im digging them up it would improve the soil texture.Anyone done this?
I don't envy you digging spuds in heavy soil. In future years you could always try spreading the muck on the surface and just pushing the seed potatoes a few inches through some holes cut in black polythene. It's what I do now and I'm just surprised that it's not done more widely.
If you understand that the plant produces most of its tubers just below where the stalk meets the ground
the advantages are that when you lift the polythene at the end of the season all the spuds are sitting on the surface like a well behaved crowd of Bolton Wanderers supporters and all you have to do is gather them up without digging too much. I usually sieve the top few inches for the ones that want to play hide and seek and it stops all those unwanted spuds coming through next year that you didn't find and you now don't want.
I've also found that I get less disease problems because the polythene seems to shield them from nasty viruses, the worst being spraing in my area and I've never had it since growing them like this. Another advantage is that because you spread the manure on the surface with this method it gets taken down by the worms and is readily available for the next crop you rotate to that bit of ground. I've found that digging manure into soil makes it leach out far more quickly than if you just let nature do the work for you, gradually. Just keep topping it up.
You might want to run some irrigation pipes under the polythene to give them a good drink after they've flowered but I don't bother and just water the foliage and the plant takes it down to the tubers. Always had good sized spuds with this method. No slug problems either. I don't know why I didn't do it years ago when Geoff Hamilton did it on one of his gardener's word programmes. And of course the cherry on the cake is that there is no messing about with mounding up AND THERE IS NO WEEDING!