Clay soil and Lime

[nepia]

If the clay's only a foot thick punch some holes through it and fill them with hardcore, road planings etc. Hopefully the drain below hasn't silted up through lack of throughput!

[Dean O]

got clay soil in the garden - mixed in lime when digging the veg patch - along with rotted down chiken poo.

worked wonders

I think the process is called floculation - the clay particle bind together in clumps oppening air spaces and allowing drainage-

 

but i dont think that it would be as effective on an area where its spread above ground without the soil being turned/ churned as farmers do when the lime then plow the field.

 

might be worth a go tho.

 

if this is the approach could you lightly spread sand over the grass to help drainage too??

[Dean Lofthouse]

Only problem is the site is 100m x 80m so the lime thing is a very simple answer to an otherwise nightmare of a job.

 

About a third is woodland, a third yard and a third grassed, so it is the dream solution provided the plantings and grass can tolerate a ph rise to 10.5 ?

[Dean O]

would be a bit worried about burning the grass off TBH

[fencer]

you could always sub soil the ground to help brake up the soil _fencer

[tommer9]

I think your right Dave just found this:

 

When adequate quantities of lime and water are added, the pHof the soil

quickly increases to above 10.5, which enables the clay particles to break down.

Silica and alumina are released and react with calcium fromthe lime to form

calcium-silicate-hydrates (CSH) and calcium-aluminate-hydrates (CAH). These

compounds formthe matrix that contributes to the strength of lime-stabilized

soil layers. As this matrix forms, the soil is transformed fromits highly

expansive, undesirable natural state to a more granular, relatively impermeable

material that can be compacted into a layer with significant load bearing

capacity. In a properly designed system, days of mellowing and curing

produce years of performance. The controlled pozzolanic reaction creates a

new material that is permanent, durable, resistant to cracking, and significantly

impermeable. The structural layer that forms is both strong and flexible.

 

 

and a good explanation here:

 

http://www.lime.org/LTStechbrief4pdf.pdf

 

It's really good to know if anyone has got a yard with is clay based soil there can be drastic drainage improvements simply by adding a bit of lime ......wow !

 

Hold on mate- that says that it will be significantly impermeable- that means it will NOT let moisture through...

[Dean Lofthouse]

I think it means the soil molecules Tommer..

 

Where clay molecules soak up and hold moisture, the new ones dont so water will pass through the structure of the soil ??

[Cracker]

I'm on clay. We add lime and sand to make the soil workable. Mole ploughing works well if you're not driving over it constantly, you have to redo it every few years. No substitute for proper drains in my opinion. Clay pipes, ditches, etc, all over our land. That perforated plastic stuff works OK if there's enough of a drop, otherwise it silts in no time.

The problem is the layer below the topsoil which is compacted clay. This is what the water can't get through. Adding lime and sand just makes the top soil workable, it don't get down to the sub soil, so during heavy rain it fills up.

[Dean Lofthouse]

I have also thought about building a sump at the lowest pointand then running a pipe away from that at a certain height so I will have a ready supply of water to water plants etc but it wont over fill because of the drain off pipe.

 

Thing is I'll still have the problem if the underlying clay swells and doesnt allow free drainage

[ging]

sending the soil to pH of 10.5 ait gonna be going too favourably for plantings, thats really quite a high alkalinity, and worms, afaik, wont much like it either, i'm lead to believe there quite sensitive to pH 6 - 7 mark.