Alkaline soil, things don't grow -- What should I do?

I've been trying to start a garden at my two-year-old house, but the soil is just horrible, and most things just don't thrive in my outdoor garden. Villagers kept telling me that the soil in my area is no good, and I'll have to bring in about 10 inches of soil from a desert location on the other side of the village. I thought it was maybe too silty-sandy and that organic matter and mulch would solve everything, but as much organic matter as I mix in, it sort of just disappears in the soil. A fair bit of cement was mixed on the ground leaving uncured or poorly cured cement bits throughout, but now I'm thinking it's not only that.

Recently I realised that since asparagus is the only thing that thrives in my outdoor garden, maybe the soil is alkaline. So I tried pouring vinegar on it, and sure enough, it sizzles right up. Ugh! So now, when irrigating plants in the outdoor garden I add some liquid gold and a little vinegar to make the nitrogen available. But this is not a long-term solution.

In my greenhouse, which is open to the sky in summer, things grow fine, and it happens that the soil in there is brought from elsewhere, and vinegar does not fizz on it.

I don't think soil tests are available to the public here.

I'm trying to decide if next winter I should go ahead, hire a JCB to dig out 10 inches of the garden and bring truckloads of new desert soil, and start over afresh with truckloads of manure too. Or should I try to find out how to get sulphur here and try amending the soil?

I have a silly question. How cheap and readily available is vinegar, and what would it do to the soil?

My understanding was that most plants, but particularly arid-climate plants, or those whose season factors in a dry season, produce acetic acid in times of drought stress as a means of self-preservation. I will try to find the article that explains the mechanism, as I didn't grasp it the first run through. But essentially, it exists in some form in nature, and as a part of most plants' biology. If it left no undesirable residue, what would be the effect of simply neutralising the soil?

I know it would kill off any soil bacteria that are there, but I don't think you'd want those ones there, anyways. I think that maybe neutralising the soil, adding organic matter, and dousing it regularly with a compost tea, or ideally an actively aerated compost extract, and fungal slurries should probably work to turn almost any soil that isn't exclusively mineral into something that holds nutrients and supports life.

To be clear, though, this is a spot that was likely contaminated by human activity. Is the rest of the soil there alkaline? Are there pioneers that don't seem to mind? I would test the soil around those pioneers with vinegar, if that is the case. If they are already neutralising the soil, and if you have the time to let them do so, you could encourage their seeding over the plot. That might be a good idea even if you amend it to neutrality, depending on the severity of contamination, and what you intend to grow there.

If I was growing fibre or dye plants, or fuel, I would try to see if any of what I needed could grow there, and might uptake something that might be okay in a fibre, dye, or fuel, but that I wouldn't want to consume in my food; heavy metals and alliums come to mind. Testing, or finding plants sensitive to the contaminants and sewing them seasonally until they thrive, are really the only two ways I can think of to tell when the as yet unknown but likely heavy metal contaminants are gone and it would be safe to grow your garlic and shallots.

I was also thinking alfalfa, or lucerne, if any variety grows where you are, if the contamination isn't bad, or if it's just a little alkaline. I might be mistaken, but I think I remember reading that alfalfa likes an alkaline soil. Couple that with a deep taproot, and if it's appropriate for the remediation, it gets a lot done in one plant.

I would love to see more pictures. Good luck, and take care.

-CK

Hmm, now I tested the vinegar in some other spots on my land and it doesn't fizz. So shit, I guess the contractor polluted the south facing front of the house with mixing cement (It's a rammed earth house but has RCC tie beams at 3 levels, and cement plaster in the bathroom).

So, could sulfur neutralise the alkaline cement? Or should I dig it all out? Ugh!

Yeah, alfalfa is the main fodder plant in this region.

I would be inclined to build up,  not dig out.
Even if you don't want raised beds,  adding 10" on top of the existing soil seems less work/money than removing and replacing.
While we are talking about moving bulk materials, is there a way to get 10"  of composted manure instead of or in addition to the soil?

Do you have access to compost?

I have planted grass directly into compost with amazing results.

I remember reading that one of the members here made her garden beds from sand and any organic matter that she could get her hands on such as vegetable scraps, coffee grounds, leaves, grass, etc.

One thing you could try is to make a raised bed with a sunken middle that can hold a pool of water, then fill it up and let it drain a few times. The idea is that the water-soluble alkali ions can be rinsed down and out of the bed. If the alkalinity is coming from the soil minerals themselves rather than a buiidup of salts or whatever, then this method probably won't work.

If you can get some sulfur and dig it in along with whatever organic matter is available, that should help. Are there cedars anywhere near you? The litter from most conifers tends to the acidic end of the scale and that would be a good mulch.

Actually, I was thinking about using a readily available bioaccumulator, alfalfa, to first sequester  anything questionable,  and then, or if there's really no issue beyond too much lime dumped in one spot, just graze local livestock on it in rotation. Bam. 10 inches, right there, if not immediately,  then over time.

And then it can grow whatever you want. I like the idea of raised beds where appropriate, but that's not always the case.

-CK

Raised beds are not a great idea for the outdoor large garden, because watering is generally done by gentle flood irrigation from a canal, so the beds have to be below ground level, and below the level of the little canal. I have seen on the internet that people refer to this as waffle gardens? Anyway it's just the normal way, here. Currently I'm using a hose so raised beds would be okay, but I'm planning to eventually landscape the rest of the land so that I can do the normal canal thing. (There's no precipitation to speak of here, so irrigation is essential. I'm in some extreme desert.)

Abe Coley wrote:One thing you could try is to make a raised bed with a sunken middle that can hold a pool of water, then fill it up and let it drain a few times. The idea is that the water-soluble alkali ions can be rinsed down and out of the bed. If the alkalinity is coming from the soil minerals themselves rather than a buiidup of salts or whatever, then this method probably won't work.

Yeah, I've been doing this somewhat since I realised the soil is so alkaline, and I think it's helping, though I'm not sure. Now when I water, I really flood each bed at least an inch and let it soak down, and then do it again. Not every time, but every few times.

Pine trees SLOWLY make soil acidic.  If you had a regular source for pine straw to mulch with, that would be a help over the long term.

Generally, any kind of mulch will help.  Raising the soil organic matter (SOM) helps remediate the problems of PH on either end of the spectrum -- acidic or alkaline.  

I agree with the suggestion above -- its a whole lot easier to build a raised bed on top of the suspect soil than it is to dig it all out.  I'd go that route.

No pine trees for hundreds of miles and over Himalayan passes, so pine mulch is not likely to happen.

I'm going to add as much organic matter as I can anyway, and have been doing so for these first two summers, but this soil just eats it up and leaves no trace. I think it's really too far alkaline for organic matter to do enough good in the first couple of years. I've got a composting toilet ready to be emptied next year that'll be good (sawdust and autumn leaves were the main cover material), and I have access to good amounts of dry cow dung, and will get autumn leaves from neighbors.

I'd like to hear if anyone is familiar with soil polluted with cement, and if sulfur would actually help or just make a new kind of problem.

I had a garden bed in this situation when the neighbor replaced our dividing fence and went overboard on the concrete for the posts.  Almost everything died there as a consequence (I actually had a thread about it here at the time, maybe I can find it).  Even the weeds wilted and died and nothing grew there for about a year.  The rest of the garden was unaffected.  I initally made one small raised bed on top of it later in that first year and grew a few kale and broccoli in that;  I put down some paper and cardboard and loaded some grass clippings on top (the only available organic matter I had at the time).  The kale and broccoli grew ok, and by the next year weeds were starting to grow there again.  

I really haven't done anything to amend it, though it's had some chicken bedding spread over it maybe once since then--I think this all started maybe 2014?  Things do grow there now, though it's still not as productive as it once was.  I should mention it's not a very big area;  I would say around 2 m x 4 m at most.

I found my old thread:

https://permies.com/t/36969/find-wrong

G Freden wrote:I found my old thread:

https://permies.com/t/36969/find-wrong

That thread was in 2014. Has your soil and plants recovered? Did you conclude it was the alkalinity from concrete? Curious minds want to know!

Happy update
Well, I seem to have succeeded in improving the soil in my garden just by adding plenty of cow manure and by stubbornly persisting in trying to grow stuff. Last summer the garden did great. I've also been buying elemental sulfur (expensive single kilos of pure sulphur from amazon.in, and more recently 25 kg of something less pure from a big city) and mixing it in bed by bed as I work over the soil, but most of the productive beds last summer hadn't had any sulfur yet, just cow dung.

In winter, while irrigation is stopped for many months, an impressive amount of white mineral crust rises up from the soil to the surface. It's especially around the earlier started beds, that haven't had as much manure added. The more recent beds, made last year when I had more cow manure, don't have as much of the white crust around them. I probably mixed more sulfur into those newer beds, too.

My first summer of the garden at this site, 2019, for example I planted beans: they produced one or two bean pods each, on plants that were 4 inches tall, with 4-inch beans dragging on the ground. Pathetic! But that same bed has had cow manure added each year, and in 2021 produced corn nicely. Other beds produced lots of tomatoes, winter squash, broccoli, beets, herbs, etc.

So I encourage anyone with alkaline soil to just push forward with as much compost and manure as possible. This wasn't even fully composted cow manure: it was desiccated cow pats that I got truckloads of, piled up in early spring, watered for a few weeks in chilly weather, and then dug in. And it worked great.