Polytunnel soil

[Vince G]

My polytunnel is in its second summer. In it I grow toms, peppers/chillies, aubergines, cucumbers, melons, a few sweetcorn and some salady bits over winter.

Before I erected it the soil was well manured and I manured it again winter 2012/13.

My question is this: given that this polytunnel is hopefully going to stay in place for several years, how do I keep the soil healthy and what else should I add to it apart from muck.....or maybe I should dig it out to a certain depth and replace it somehow...

Any thoughts or advice anybody?

[Aberdeenplotter]

In a poly tunnel you will invariably end up with a build up of salts which affect the conductivity of the soil which prevents the plants absorb the chemical nutrients. There are three options to remedy this.

1. Remove the cover over winter and allow the rain and snow to flush out the excess salts

2. Barrow all the soil out into the open to allow the rain and snow to flush out the excess salts and after winter barrow it all back

3. Thoroughly soak the soil with a hose several times to flush out the excess salts.

[Alison]

I also rotate my veggies in the tunnel so won't grow the same family in the same bed straight afterwards but it does depend on how you use your undercover space.

[Snadger]

I agree with AP and Alison but can add another probably un-viable solution.............rotate the polytunnel to a different position every couple of years!

[Vince G]

I think the thorough soaking / flushing is really the only viable option for me. I actually do that when the soil is bare in there anyway as otherwise it turns into a bit of a dustbowl. Removing the cover is not going to be possible as I'll have things growing in parts of it in the winter, and nor is moving it really - the thing took 3 whole days to put up in the first place!!

[bravo2zero]

see a post I made some months back that will give you some answers. ive had my tunnel up for ten years and not had to change the soil YET. with regards to salt build up during periods of non cultivation keep it covered with old compost bags to keep the moisture in and mulch with straw, manure or garden compost between plantings.