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noobgardener2010

Water repelled by soil/dirt

noobgardener2010
12 years ago

So when I water this section of my backyard, the water beads and runs off instead of soaking into the soil. Even when I till the soil, only a thin top layer gets wet and if I poke it with my finger I can see dry soil underneath. The red arrow points to a dry area where the water has beaded off.

I'm interested in knowing if there is a technical term for this effect so I can figure out how best to fix it. I could just mix in compost and soil and whatnot, but then I won't have learned anything. Thanks for any help

{{gwi:290256}}

Comments (34)

  • taz6122
    12 years ago

    The soil is hydrophobic. Misting it several times a day will take care of that. Once hydrated, keeping it moist will be easier. This only happens when it's left to get bone dry IME.

  • noobgardener2010
    Original Author
    12 years ago

    Thanks for that info. This area of the yard has been neglected in terms of watering since I had nothing growing in this section this last year. When I moved in last year there was nothing growing there either, so I bet the people who lived here before also didn't water the area.

  • kqcrna
    12 years ago

    I'd water first with soapy water, then apply a soaker hose at a very, very, slow drip for a long time.

    Karen

  • Kimmsr
    12 years ago

    Soap, added to water, reduces the surface tension of the water and that will allow the water to flow into places water with no soap would go. That is a short term solution to a complex problem which means you need to look closely at the soil to see why it is hydrophobic. More than likely nothing grew there because there was no moisture in that soil due to that hydrophobia.
    Was a large amount of a petroleum product dumped there previously?

  • ceth_k
    12 years ago

    At first glance I would guess it is a sandy soil problem. Sand is very 'water repelling'. Maybe you could try adding some clay to make it more water absorbing ?

  • zuni
    12 years ago

    What you are seeing is the effect of cohesion between water molecules. The lack of moisture in the soil actually makes it harder to make it moist.

    Two suggestions: first, compost, compost, compost. Compost improves both clay and sand soils by holding moisture in the soil.

    Second, after a rain or long, slow irrigation: add a layer of mulch and then ALWAYS keep the soil protected this way. Mulch maintains the moisture in the soil, and protects the soil structure from wind erosion and compaction from rain.

    As a note, don't use soap on garden soil. It will kill whatever beneficial microbes may be there, and you need them all! Soap is sometimes added to foliar sprays to make them stick to leaves, but is not good for soil.

  • noobgardener2010
    Original Author
    12 years ago

    I don't know the previous history, but I see no signs of petroleum product contamination.

    I get the feeling that this part yard has simply been ignored. The fruit trees and main flower beds are all on the other side of the yard. I myself planted my first vegetable garden last year on the other side. I only noticed this because I wanted to expand my garden and decided to use this new area.

    I have plenty of compost and will also use the slow drip water method. I think I'll avoid soap for now, since I plan to eat what I grow there(if I manage to grow anything there haha). Thanks for all the suggestions.

  • kqcrna
    12 years ago

    To my knowledge, good old soap does not kill bacteria. Antibacterial soaps or detergents kill some, but not all bacteria. But not soap.

    Soap, in combination with water, dissolves and loosens dirt when you wash your hands. Water then rinses it off. But it doesn't kill germs unless it's an antibacterial one.

    You people fear soap??? What do you bathe with? What if soap (gasp!) would get into an open wound??? If you're afraid to put soap into soil where food is grown... what do you use to wash your dishes?

    Endless entertainment here, folks.

    Karen

  • Kimmsr
    12 years ago

    Karen, the Center for Disease Control and the National institute for Health both came out several years ago and stated that the anti bacterial and anti microbial soaps are no more effective at killing disease pathgens then any other soap. Using the anti bacterials create major problems also because the use of them allows many disease pathogens to develop immunities to them and they will kill the bacteria in the waste stream which causes the waste treatment plants to have to add bacteria to digest that sewage sludge and if you are in a rural area with a septic tank you will kill the bacteria that is supposed to digest the sludge in your septic tank and will require pumping much more often.

  • kqcrna
    12 years ago

    Lazy, I know that when washing (e.g. one's hands) bacteria can be destroyed because of breakdown of lipids of cell walls, but I thought it was soap and friction combined. Besides a mild soap solution applied to soil surface, followed by slow soaking with a lot of water would provide a very dilute solution . I often spray bugs on my plants with soapy water. I don't worry about that little bit that hits soil. And I have applied soapy water to hydrophobic mulch with a sprinkling can, followed by soaker hose, with good results.

    Kimm, I don't think your information is correct. I am aware of mutations caused by antibacterials. But antibacterials have been shown to work much better at prevention/transmission of of disease. (which is why they're used almost exclusively in surgery)
    My source: I am an anesthetist and have worked in the OR for over 30 years.

    Karen

    Here is a link that might be useful: CDC

  • socalgal_gw Zone USDA 10b Sunset 24
    12 years ago

    I have beds that act like this after being dry all summer. I have to use a lot of patience to rewet them, watering them and allowing a day for the water to distribute, then repeating that. Sometimes I'll dig a bunch of shallow holes and fill them with water, then wait. If I had a drip system or a sprinkler that would probably work very well. If it rains before I want to plant in those beds mother nature does a great job of watering them slowly over a long period and they rewet very well.

  • jolj
    12 years ago

    I do not think that many microorganisms will live in hydrophobic soil.What does it matter, you need to fix the soil. Then worry about building up the micro, if I remember right they live for a few second at most.
    And it is easy to rebuild the soil food web or we would all be dead by now. I have been hearing boom & gloom all my life & we are still one of, if not the top producers of food in the world.

    My Source: I am a hick that work the soil for 42 years & my wife is a Microbiologist who taught the subject in the Techincal school for 4 years.

  • dottyinduncan
    12 years ago

    My sister used to grow the most amazing dahlias. Her secret? She took her dishwashing water and threw it on her dahlias. Soap, detergent? It was in the 60's so I don't know, but those flowers sure grew large! I've had the same problem as the original poster trying to wet overdry soil and soap really helps.

  • jolj
    12 years ago

    The big dinner plate ones or the saucer size.
    I love Dahlias, but so do the deer.

  • Kimmsr
    12 years ago

    Karen, I cannot find either of the items from the CDC or NIH, but they have changed their recommendations a few times. I remember being told by them to wash hands for one minute, then 15 seconds, now 20 seconds. The link below, from Minnesota Public Health, has some of the information I have seen. The Infection Control people in hospitals try to teach something different then the general public gets, but they have larger problems to deal with.

    Here is a link that might be useful: Disease control

  • kqcrna
    12 years ago

    Yes, Kimm, I know that stuff from surgery. I'll link you to CDC recommendations for hand hygiene in healthcare workers.

    It's a long document, but quoting page 8 "reviewing preparations used..."
    "Plain soaps have minimal, if any, antimicrobial activity."

    But the subject here wasn't hand hygiene, it was using soap on soil. Works for me. We had a horrible drought last summer, with sustained heat too, 12th hottest summer ever recorded. I used buckets of used dish water on my from bed a lot. You can see the effect.
    {{gwi:265836}}

    It was the prettiest my yard has been in nearly 30 years.
    {{gwi:265837}}

    Karen :-)

    Here is a link that might be useful: CDC recommendations

  • dchall_san_antonio
    12 years ago

    Getting off the soap topic and back to the OP's issue for a second...

    noobgardener2010, the reason your soil is hydrophobic is that the population of beneficial fungi has been reduced by the dry conditions. Beneficial fungi are the creatures that allow water penetration naturally. When you have a plentiful supply of them, they will cause your soil to act exactly like a sponge. That means the soil will repel water for a moment but once the surface has been penetrated, it will absorb water, well, like a sponge. When the soil is moist it will be soft. When the soil is dry it will be hard. But if the soil is dry for too long, you will lose that population causing the soil to become hydrophobic.

    Beneficial fungi must have a relatively constant moisture content and air to survive. If you cut off either one you will soon have problems. Your soil is the result of cutting off the moisture. If you have a low spot that holds water for several days after it rains, the water cuts off the air and the beneficial microbes die. When they die from having the air cut off, the normal plants tend to die and be replaced by swamp-loving plants. Nutgrass is one of those swamp plants.

    The solution I like the best is the one you have chosen. Inches of compost and/or mulch will keep the soil temp and moisture content even enough for the beneficial fungi to return.

    Now back to soaps! I believe the soap (not disinfectant) will also work for you, too. I spray with baby shampoo when I find that my soil does not become soft when wet. The soap allows the water to penetrate like the fungi do. Once the moisture drains deeper into the ground, it will stay there long enough to reestablish the beneficial fungi population. If you would like to try a more organic approach to softening the soil, sugary substances also change the ability of water to penetrate. Molasses is a good choice for that. There are also natural surfactants found in the yucca and aloe plants. You can find extract of yucca in many nurseries.

  • jolj
    12 years ago

    The beneficial fungi are just one thing & can not do it all by them self. You sound like the guy that said vitamin C is the cure for all disease.
    If the fungi could do it single handed, everyone with clay would put them in the soil to improve drainage.
    My nut grass(Cyperus) grows in dry sandy soil, year around.
    Love the photos of the flowers.

  • dottyinduncan
    12 years ago

    kqc, what a beautiful garden! I'm totally jealous and full of admiration for your efforts.

  • dchall_san_antonio
    12 years ago

    Beneficial fungi is, possibly, 50,000 things - not one thing. The fact that it is so many things is what makes it a good theory as to why/how the soil becomes wettable.

    If the fungi could do it single handed, everyone with clay would put them in the soil to improve drainage.

    Welcome to the soil and compost forum where people discuss composting as a way to put organic matter into their clay soil to improve drainage. The purpose of compost is to put microbes, 10s of thousands of which are fungi, into the soil. People are doing it. You might want some compost to improve your dry sandy soil and possibly get rid of the nutgrass. Your nutgrass is getting water from somewhere.

  • noobgardener2010
    Original Author
    12 years ago

    I've mixed in compost and I'm running a slow drip from my hose. I have one more question:

    This drip method, how big of an area does it cover? Assuming I'm doing a slow drip over 8 hours, is it just that immediate(say 2 foot by 2 foot) area that's 'fixed' or can I assume that slow drip has spread?

  • dchall_san_antonio
    12 years ago

    I used to run a drip soaker hose. I started with 75 feet of it stretched out along the edge of the yard. The flow rate out of the faucet was 1 cup per minute. I left it on day and night for 7 days and then moved it to the next spot. The next spot for me was about 18 inches away based on the area that looked wet. I moved it to the edge of the moisture.

  • noobgardener2010
    Original Author
    12 years ago

    Thanks for the reply. My experience to this point is similar.

    I'm using a regular hose, with no spray nozzle on the end, just the regular hose opening. I have it on a very low trickle. So I can only do one spot at a time but that's fine because I only have about a 20' by 15' area to do.

    So far it is working! The first area I did, I dug a hole to check and the soil had moisture as deep as I dug(~ a foot). Before, after what I considered a good watering only the top 1/8" or so was actually wet, lol. I figure it's going to take about a week to get the entire area up to speed.

  • jolj
    12 years ago

    It takes more then just fungi.
    I have 24 acres, can not compost it all, but I am getting a good start, with about 40 tons of coffee waste & green fruit beetle grubs, with burlap bags for mulch.
    All of this county is sand, ancient sea shore, been composting on it for 37 years.
    {{gwi:290257}}

  • jolj
    12 years ago

    Hi noobgardener2010, how is the soil now that you have wet it?

  • noobgardener2010
    Original Author
    12 years ago

    I got lucky with the timing.

    First, I've been drip watering for 12 hours a day. That has created a large area of soil with moisture inches deep.

    Then out of the last four days, three of them have had rain. Not a lot but steady showers throughout the mornings.

    So I'm way ahead of the schedule than I thought I'd be, which is great since this is going to be my corn/pumpkin area. I'm really impressed at how well slow drip watering works. I always thought it just was what people too lazy to hand water did, that or use sprinklers. Now I'm looking into setting up a built-in drip irrigation system.

  • kqcrna
    12 years ago

    That's great, noobgardener. Now, keep it moist. If you can top the area with a layer of compost, and an organic mulch on top of that, it will help you a lot.

    If you mulch with something like grass clippings or fall leaves, it can mat down and not allow water to penetrate if applied to thickly, so you just want a thin layer- maybe and inch. Straw on top is great for conserving moisture. The organic mulches will break down and add more organic matter to help prevent the same problem in the future.

    I sure wish I could send you some of my rain :-(

    Karen

  • jolj
    12 years ago

    On this link on page 3.
    Every 1% increase in Organic Matter increase the water holding capacity by 100%.

    Here is a link that might be useful: rain water retention

  • Joey1987
    12 years ago

    Does the soaker hose method use alot of water? I live in South Africa where water is quite expensive and we have restrictions. I also suffer with hydrophobic soil. I worked in some earthworm poop, but no results yet. However, I bought a very nice garden hose handheld fitting that allows me to mist the soil. I hope this works, because I just planted tomatoes, beetroot and butternut in this soil. I remember my herbs and tomatoes growing in this soil a few years back when it was also hydrophobic, though. So I'm thinking that slow watering will help a great deal.

  • lazy_gardens
    7 years ago

    Joey - If you have soaker hoses or drip tubing UNDER a thick mulch, all the water goes into the dirt for the plants. It uses less than any other method.

    The mulch will minimize evaporation and keep the soil moist longer.

  • toxcrusadr
    7 years ago
    last modified: 7 years ago

    Did you notice this thread was from 2011? This appears to be Joey's only post.

    Interesting thread though and I enjoyed reading it. One thing that was never mentioned in the 'soap kills microbes' debate was concentration. When you lather up your hands, the concentration is much higher than when you put a few drops in a gallon of water. This is critical because surfactants dissolve oils - and cell walls which are lipid based - based on their concentration. There is a threshold concentration above which micelles will form in solution. I suspect it is much higher than what is used to make water more 'wet'. There are natural surfactants in soil already, and they don't kill soil microbes. Also, if soap killed everything regardless of concentration, sewage plants would be killed. But the truth is quite the opposite: most surfactants biodegrade quite well in the sewage plant - because they are diluted. I would have no qualms about adding a small amount of non-bactericidal soap to water for hydrophobic soil.

  • jolj
    7 years ago

    Joey will get an email just as I did.

  • toxcrusadr
    7 years ago

    Good then. Maybe he will actually come back and give us a report on how this turned out.