Improving clay soil

Sive · Posted: Thu Jun 25, 2009 12:52 pm Post subject: Improving clay soil

Over the past year or two I have started a new garden which is essentially on a clay-type soil. Now that all our compost heaps have been established, I will have endless amounts of compost, and also lots of horse manure ( given by a neighbour ) which will all add lots of organic matter to the soil, year by year.
Question is: should I be digging this right in, to mix it up with the clay....? Or will putting the manure and compost on as a surface mulch do the same job in the long term...?
I know that the theory is that earthworms do the hard work....but does that really happen even in a heavy-ish clay soil?
I would be grateful for some guidance on this. Thanks!

michael brenock · Posted: Thu Jun 25, 2009 4:46 pm Post subject:

the theory is fine about-the earthworms but it would take them a long time to do it and there is probably very little incentive for them to do it. You should dig in the manure and compost and mix it as much as you can. it is better to treat a small area at a time and see the results earlier and then move on to the next area and besides you will have standards of comparison between the improved and the untreated.
michael brenock horticultural adviser (retired)

Sive · Posted: Thu Jun 25, 2009 7:30 pm Post subject:

Thanks Michael, what you say makes a lot of sense, and it is what I suspected instinctively ....I suspect nature probably needs a helping hand on clay soil. I just wasn't sure if I was making extra work for myself !

medieval knievel · Posted: Fri Jun 26, 2009 9:21 am Post subject:

i've heard that digging gypsum into clay soil helps loosen up the structure too.

also might be worth getting some horticultural sand, and digging it in along with the compost and manure.

Sive · Posted: Fri Jun 26, 2009 6:23 pm Post subject:

Thanks for that mk, I'm sure sand would be good and while I've never heard of using gypsum, I'll do some research into that too.

medieval knievel · Posted: Fri Jun 26, 2009 7:18 pm Post subject:

http://www.humeseeds.com/gypsum.htm

Sive · Posted: Fri Jun 26, 2009 8:51 pm Post subject:

Wow, how fascinating. Thanks mk, I've certainly learnt something totally new there. Now I have to look around and see where gypsum is available !

michael brenock · Posted: Fri Jun 26, 2009 9:33 pm Post subject:

The neutralising effect of Gypsum should be beneficial if the soil is acid. I would recommend the use of spent mushroom compost which will neutralise the acidity if needed add humus and some nutrients also.
Michael brenock horticultural advisor (retired)

Sarah Evans · Posted: Sat Jun 27, 2009 6:54 am Post subject:

And you cant beat leaf mould as a free soil conditioner. See links for details......

http://en.wikipedia.org/wiki/Leaf_mold
http://www.videojug.com/film/how-to-use-leaf-mould

Sive · Posted: Sat Jun 27, 2009 8:52 am Post subject:

Thanks, michael, the soil is actually not acid, which I'm glad about as I'm not a fan of acid-loving plants!
As for leaf mould, Sarah, I was able to make loads of it in my last garden in Dublin, thanks to the density of suburban tree planting. Unfortunately here we are starting from a bare canvas, with no existing trees at all, but hopefully it won't be long before all the trees we've planted will provide us with the leaves every autumn!
Thank you for the links, I'll enjoy looking at those now.