Improving Heavy/Peat Soil

hexosan

Hi
I'm building a house at the moment on a 2.5acre site.
The soil conditions are extremely poor, the entire field consists of black peat over grey marl. The peat around the garden area of the house is approx 2m deep.
Ground is desperately wet most of the time and you cant bring any heavy machinery on it.
Anyone any thoughts on the best way to improve the drainage of the soil and PH levels.

Any suggestions would be appreciated.

PS I've been told by some that I need to spread sand (to help with drainage) and lime (improve the PH) and then deep plough the whole lot to mix it up. I've no knowledge of any of this so no sure what's best.

PPS Just to mention I have access to a 1.5m deep land drain running the full length of the back of the site.

Oldtree

Aful costly to do all that work and you will be on an uphill battle all the time. an alternative is to work with what you have making a wetland garden choosing plants suitable to the conditions you have, also perhaps a number of raised walkways, streams, pools. Going for more a wild garden.

hexosan

Thanks for the reply. Wasn't planning on doing the whole site might just fence off the top section and keep 1/2 or 3/4 acre around the house for the gardens. Probably put a horse (they been on it before) or goats on the rest to keep down the grass.

With that in mind am I on the right track with the sand & lime. Sand was suggested over organic matter as while more costly once it's in it in, whereas I'd have to stay reapplying the organic matter. Is there any other way of improving the soil.

Sonnenblumen

hexosan wrote: »

Hi
I'm building a house at the moment on a 2.5acre site.
The soil conditions are extremely poor, the entire field consists of black peat over grey marl. The peat around the garden area of the house is approx 2m deep.
Ground is desperately wet most of the time and you cant bring any heavy machinery on it.
Anyone any thoughts on the best way to improve the drainage of the soil and PH levels.

Any suggestions would be appreciated.

PS I've been told by some that I need to spread sand (to help with drainage) and lime (improve the PH) and then deep plough the whole lot to mix it up. I've no knowledge of any of this so no sure what's best.

PPS Just to mention I have access to a 1.5m deep land drain running the full length of the back of the site.

What a very interesting challenge, with plenty of scope and nothing too difficult to improve. For starters, a few days to install ( depth minimum 900-1000 mm and use 150mm pipe, trench should be min 300mm wide and ensure pipe is wrapped in membrane and embedded all round in min 300mm of drainage gravel) decent land drains with very good falls and connect to existing pipe will make significant improvements to the water table. Do not skimp, invest in good network of land drains, this will have lasting benefits.

I wouldn't bother adding sand and/or lime for the moment, better to plough the meadow area(s) and bring and bring in a new top layer (100-200mm of good soil) in selected area. The remainder of the site can be ploughed adding some grit/small pebble to improve drainage/soil condition. Given the significant depth of peat I wouldn't bother trying to change the pH, would require significant amounts, better sense to use plants which prefer acidic ground conditions (plenty of choice too).

hexosan

I have already installed land drainage all around the house (wrapped in membrane) to divert water away and into the drain at the back of the site.

I've been told to look at Connaught agri pipes as the have a membrane sock on them and they don't need to be back filled with gravel. Anyone used them in peat soil.

shotie

the above is something like we got done on our land a while back we dug trenches all over a wet field all leading into one big drain we put stone/gravel into the trenches and covered them back up is has done a great job draining the land. you could also dig out the peat and back fill with stone/gravel and put good soil on top but still have good drainage just to be sure.

Sonnenblumen

hexosan wrote: »

I have already installed land drainage all around the house (wrapped in membrane) to divert water away and into the drain at the back of the site.

I've been told to look at Connaught agri pipes as the have a membrane sock on them and they don't need to be back filled with gravel. Anyone used them in peat soil.

Some research on installing land drains on wet sites will set you straight. What you're dealing (lots of water and poor drainage conditions) which requires much more work than might typically be involved in tackling surface water.

The bigger the pipe and the better the specs (membrane, gravel etc) the better the results.

macraignil

Another way to improve poorly drained soil could be to plant suitable trees. Alder and willow are both suitable to growing in damp soils and in time may improve the soil structure naturally by reaching deeper into the soil with their roots and bringing organic matter to the surface when their leaves fall in the winter. Coppicing the trees involving cutting back to the stump every few years allows for a regular supply of wood. Alder makes good posts for woodwork and when dried could also be good firewood. There are a number of plant nurseries that offer competitive prices for young trees and I personally would try fill most of the area with alder trees to provide my heating fuel in a few years time. Blue berries also like peaty soil so could be a crop you might consider.

I improved a small area of heavy clay by adding a couple of small drains made from standard PVC pipes and planting some fruit trees. I found as the fruit trees have matured the area is not getting waterlogged and the drains do not seem to spout out water as much as they used to. It appears the trees have opened up the soil so the drains are not needed any more as water is now soaking away more freely.

hexosan

Willow has been suggested before as a crop to plant on the remainder of the site to use as a fuel source in the future. This is something I'll look into. Wasn't aware of blueberries been suitable to peat soil.