how best to lower the pH of alkaline soil?

Discussion in 'Planting, growing, nurturing Plants' started by piano_dan, Jul 22, 2007.

  1. piano_dan

    piano_dan Guest

    Hi Folks,

    I'm a new face at the nursery but i'm KEEN 8) (and planning to stay so)

    My first real challenge is my soil pH. At around 7.5 - 8 it's a bit too alkaline for the veges i'd like to grow (tomatoes, capsicum and eggplant in one patch; lettuce, rocket and spinach in the other).

    I've done a bit of research online and asked a few 'experts' and the answers have seemed a little unconvincing.

    The main suggestion is sulfur or aluminium sulfide but I saw a number of other options online including peat moss and sawdust.

    Can anyone tell me what would make a good permaculture-friendly option?

    Any thoughts appreciated.

    Cheers,

    Dan
     
  2. Jez

    Jez Junior Member

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    Welcome PD.

    Manure, compost, vermicast (worm liquid or castings) and coco-peat will all lower your soil PH and improve its structure at the same time. FWIW, coco-peat (peat from shredded coconut husk) is a bit more environmentally friendly than regular peat - it's a far more renewable source with very similar properties.

    Well rotted/composted chook and pigeon manure is about the most acidic manure which is easily available (fresh stuff will be even more acidic but it'll also take some time to break down before the area becomes plantable).

    If you're not into composting, manure, vermicast and coco-peat will do the job for you just fine - keep testing the PH to see how you're progressing because it will depend a lot on your original soil structure.

    Various sulfur sources do work, as does al sulfide, but IMO you're better off to lower PH using means which will give you improved soil structure as well.

    Good luck with it.
     
  3. paul wheaton

    paul wheaton Junior Member

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    Do you have any coniferous trees around you?

    If you are going to pay money for some short term gardens, sulfur is probably the best bet.

    For something longer term, I would plant some conifers here and there. They will drive the pH way down. While conifer duff does have some allelopathic issues, those are probably not as bad as the pH being so high.

    Another thing - plant lots of stuff that loves a higher pH!
     
  4. Logos_Flame

    Logos_Flame Junior Member

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    Yikes! no aluminum!!! aluminum is HIGHLY toxic unless it is naturally bound to silica in alumino-silacate soils. stay away from aluminum sulfide.

    the reason that compost lowers the ph is that its a natural way of creating humic and fulvic acids. YOu can also buy fulvic and humic acids and adding them to water or a your favorite nutrient mix.
     
  5. spritegal

    spritegal Junior Member

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    Actually fowl manure has quite a high pH naturally, and in particular if the manure is sourced from a commercial enterprise. This is because commercial growers feed large quantities of calcium (up to 18% in grit and supplements) to their birds for good egg production, and of course a lot get excreted in their droppings. Poultry litter can detoxify Al by increasing soil pH. This causes soluble Al to bind to organic acids (humates and fulvates) and also phosphorus, thus making it "safe".

    Your soil type also plays a significant role in the availability of nutrients and the toxicity of elements such as Al and Mg. The higher your level of organic matter, the greater the "buffer" in complexing hazardous elements so that they are readily available to be safely uptaken by your plants (and animals.)

    Application of ammonium sulfate ((NH4)2SO4), is a good way of lowering the pH of your soil. The sulfate ions are released upon application to the soil and sulfuric acid is form, which lowers the pH of the soil, and has the added bonus of contributing essential nitrogen for plant growth.

    Avoid applying aluminium sulfate unless you have a tested and quantified aluminium deficiency.
     
  6. Logos_Flame

    Logos_Flame Junior Member

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    spritegal - I have never heard of an aluminum deficiency in soil? What do you mean by that?

    good info on the fowl manure causing the binding of aluminum.

    I would imagine that mxing urine and epsom salt would create ammonium sulfate? I have recenlty been adding urine to my liquid nutrient mix (ten parts water to one part urine) and found great results with it. There was a thread somewhere around here that inspired me to do it.
     
  7. spritegal

    spritegal Junior Member

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    Hi, I should have said "aluminium unavailability" - though in Australian soils its pretty rare. I've found keeping your cation balance in the 3:1:1 (Ca:Mg:Other cations) tends to reduce the potential for Al toxicity (depending on your pH of course).

    Ammonium sulfate I've sourced from nursery suppliers in small amounts. Incitec makes "Gran Am" which is an ammonium sulfate fertiliser, available from rural suppliers.

    I've never tried the urine option though epsom salts and urine should yield ammonium sulfate. I'm not sure of the "accepted" chemical composition of urine so can't hazard whether any other less desirable compounds may be produced from the chemical reaction.
     
  8. serfsup!

    serfsup! Junior Member

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    Tree lupin (lupinus arboreus) is said to acidify soils, a good pioneer plant.
     
  9. piano_dan

    piano_dan Guest

    thank you

    Thanks Folks. That was an awesome response. I really appreciate you sharing your knowledge with a novice like myself. The internet's wonderful huh? 8)

    It sounds like the easiest and most responsible approach for me might be to add some kind of organic material, like manure or coco-peat (have to find out if that's available this far south), and then I figure I'll throw some worms on top too, to chew everything up and get it headed in the right direction.

    Eventually a compost would be good too.

    Lots of love for your gardens :p . Thanks again,

    Dan
     
  10. ali_celt

    ali_celt Junior Member

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    Dan,
    THere's a guy who advertises in the trading post here in adelaide - pidgeon poo, bagged and delivered for $15 or something.
    Whereabouts in Adelaide are you?
    If you are south, there's a place on Seaford road that sells bagged chook manure for a couple of dollars - and layer hens too if you want some chooks! Haven't been there yet myself because my hen house still isn't ready, but am planning a trip soon
    Ali
     
  11. piano_dan

    piano_dan Guest

    Wow. Thanks Ali. That's awesome :D

    I tried ringing around to track some down but didn't had any luck.

    I'm next to the city in Torrensville so maybe I'll be lazy and ring the pigeon poo guy. He does a 20kg bag for $20 (or 10kg for $12). That sounds like plenty to me.

    Thanks,

    Dan
     
  12. Loris

    Loris Junior Member

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    Our soils were off the scale alkaline due to the mineral bore water. We used to counteract that by applying flower of sulphur straight onto the soil with any other fertilizers that you want to dig in. Because the alkalinity binds the availability of nutrient in the soils, counteract by using a really top quality foliar feed for your plants and be really enthusiastic with it. This will help anything. Finally, after experimenting, learn to live with the alkaline tolerant plants that you will find and just work within those limits.
     
  13. paul wheaton

    paul wheaton Junior Member

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    Just out of curiosity, do you have anything right there that could help? Do you have any conifer trees?
     
  14. piano_dan

    piano_dan Guest

    Hi Paul,

    I'm not sure what you mean by "anything right there that could help". There's no conifers in my backyard, just a plum tree and a peach tree, as well as some assorted shrubs.

    I like the idea of planting trees to help acidify the soil, but since I'm renting, unfortunately, long term solutions aren't much help (to me).

    I'm not familiar with which plants are helpful for what (at this stage), although I would like to find out how local Australian plants could fit into the picture

    Any thoughts appreciated..

    Dan
     
  15. paul wheaton

    paul wheaton Junior Member

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    How about neighbors?

    I'm thinking that rather than drive somewhere and spend money, you could visit with a neighbor and get all you need there. Spread the good word of permaculture, build community, etc.

    I take it you are a city dweller?
     

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