hydrophobic soil

Discussion in 'Planting, growing, nurturing Plants' started by marley, Jul 3, 2006.

  1. marley

    marley Junior Member

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    I am currently staying with my mom in San Diego California and I am working on her tiny suburban garden. For the last couple of years I have been doing a lot of soil building because more than half of the garden had become a desert.

    I have done a lot of sheet mulching, adding of organic matter, making compost, and using hardy plants to colonize the bare, sandy soil.

    These strategies have helped out enormously.

    The main problem is that the original soil is extremely hydrophobic. The water runs right of the surface like waxed car.

    I was wondering what suggestions or experiences people have had with hydrophobic soils. Right now I am just trying to add as much organic matter as I can get my hands on so that I can slowly build good soil on top of the hydrophobic stuff. A sort of thin layer of rich, permeable soil has been the result of my soil building efforts so far.

    ANy ideas?
     
  2. Richard on Maui

    Richard on Maui Junior Member

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    What you have already done seems like the best things you can do, and they should turn things around in time! Another stratgey might be to plant in shallow pits or troughs, so that the water has to sit there for a while and soak in. Sort of like the reverse of raised beds for a climate where you need drainage to avoid soggy roots.
     
  3. christopher

    christopher Junior Member

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    Everything Richard says! Consider placing swales across the grade and filling the swales with biomass. That would help a lot!
     
  4. naturally inspired

    naturally inspired Junior Member

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    mulch over the top of the soil with somehting like straw which will hold the water a bit more. and keep adding heaps of organic matter like you have been.
     
  5. Loris

    Loris Junior Member

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    Seems like this could be a chemical thing like maybe altering the surface tension of the water to allow it to penetrate - talk to a soil scientist. It may be as easy as adding something common like sulphur or phosphate or something like that. Maybe even knowledgable nursery could help. Do some experiments with soil in jars.
    I had soil like this at one time and it had an established lawn which was struggling. I thought it might have lawn grubs and someone told me to sprinkle pure soap flakes on the lawn and water in which was supposed to kill the grubs.
    It worked a treat and lawn was great but it never had grubs - the soap caused chemical changes which allowed water to penetrate. Something like this might work.
     
  6. naturally inspired

    naturally inspired Junior Member

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    the soap might have worked if your soil was too acid. soap is alkaline so would ahve brought the pH of the soil up.
     
  7. ecodharmamark

    ecodharmamark Junior Member

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  8. sancha

    sancha Junior Member

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    I'll go with ecodharma on that. I've had this problem in my garden before and it happened when the largely organic soil material got really dry. When it finally did rain the water just beaded and ran off. Now I know there's a soil-rewetting product out there but I'm really sus as to what the actual components of it are and I heard that a mild detergent will work just as well (hence the success of the soap flakes). I think the detergent might work by breaking down the waxy coating on the soil particle and thus allowing infiltration of water into the soil. I should say that only a biodegradable detergent is appropriate in this case.
    I added a squirt to a 9litre watering can and it worked pretty well. I wet the soil down as much as I could first to try and get some detergent-soil particle contact happening. It was certainly an improvement, anyway, and the water didn't seem to run off as fast. That was a couple of years ago and I think I might have to do it again because I notice the same problem cropping up.
     
  9. Mungbeans

    Mungbeans Junior Member

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    Perhaps you could add some vermiculite the next time you add some green manure. This should help with the water retention.
     
  10. marley

    marley Junior Member

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    Great!

    Thanks for all the suggestions!

    I will definitely experiment with soap..
     
  11. Loris

    Loris Junior Member

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    Know the soap was alkaline but had the idea that it worked because it changed the surface tension of the water, breaking the surface tension and allowing the water molecule to bond more successfully with the surrounding. Have fun experimenting.
     

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