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Post by mskrieger on Mar 31, 2016 15:38:26 GMT -5
Just got my spring soil test back. I am a huge nerd about this. Love love love the calculations etc.
But I'm curious about certain things. I have sandy loam soil with a total cation exchange capacity of about 7. Something of a deficiency in calcium, which I'm addressing with agricultural lime and gypsum. Trace minerals are pretty good except for manganese. Phosphorus levels are good. But man does sulfur just disappear. Every year I add what I consider a maximum safe amount--about 110lb/ac--in the form of sulfates and gypsum. And the next year it's just gone, back to the 12 or 13ppm it always tests at.
Anyone have ideas? Is this an issue, or just the nature of my land?
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Post by paquebot on Mar 31, 2016 19:57:23 GMT -5
The simplest explanation is that it's now deeper than where it was applied. It must be converted to sulfate before the plants can use it. In that form, it can be leached down into the soil. If it is stopped by a layer of heavier soil, it is still available to the plants if the roots go that deep. There may be an abundance at that level but a shortage near the surface.
Martin
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Post by mskrieger on Apr 1, 2016 7:26:27 GMT -5
I wonder about that. In parts of the garden/yard that are more than a foot or so away from the exposed bedrock, there is a significant amount of clayey subsoil once you get 8 inches or so deep. I know it holds a lot of water, because I've done dry gardening experiments and watched the plants recover from mild wilting every evening as water rises through capillarity.
Now I'm wondering what else it might hold...but it might be too acidic for the plants to root in and access those nutrients. Sulfur turning to sulfate and dragging other, soluble cations like calcium down with it might actually ameliorate that situation. Hm. The only thing to do is to test the subsoil next year!
My other guess is that I'm not applying enough fertilizer. Because although I claimed above that I was applying 110lb/ac of sulfur, I'm actually quite shy of poisoning the soil and usually spread it more thinly than my calculations assume when I make the mix. Maybe I should stop being so timid.
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Post by mskrieger on Apr 1, 2016 11:20:36 GMT -5
and actually, I'm calling out swamper here, since he's an actual soil scientist living in CT. Any ideas on my sulfur? Issue/non-issue? |
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Post by gilbert on Apr 1, 2016 13:45:43 GMT -5
Are you a Steve Solomon Fan?
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Post by paquebot on Apr 1, 2016 19:23:58 GMT -5
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Post by prairiegarden on Apr 1, 2016 23:44:19 GMT -5
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Post by mskrieger on Apr 6, 2016 11:04:07 GMT -5
Thanks for the links, prairiegarden and paquebot. Going to further my education a bit! And yes, gilbert, I find Steve Solomon to have very worthwhile experience and views to share, once you get past the curmudgeonly attitude. Lately I've enjoyed running controlled experiments in my own garden, too. And sometimes it contradicts the wisdom of Solomon...like politics, all gardening is local. |
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Post by steev on Apr 6, 2016 21:55:02 GMT -5
Yes; think globally; drink locally.
Admitting my ignorance, I ask: what if you used elemental sulfur (flowers), rather than a compound? Got to be less soluble, so less transient.
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Post by paquebot on Apr 7, 2016 7:40:03 GMT -5
Doesn't matter what form the sulfur is in. It has to be converted to sulfate before the plants can use it. If it's in a form that doesn't become soluble, it would be useless to the plants.
Martin
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Post by steev on Apr 7, 2016 10:20:24 GMT -5
Right, but more slow-release?
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Post by mskrieger on Apr 7, 2016 14:22:02 GMT -5
I've used elemental sulfur in my garden before--it apparently gets converted to sulfate very quickly by microorganisms in the soil. And then immediately hooks up with any positively-charged mineral ions it can find (Calcium, Magnesium, Potassium, Uranium, whatever.) And makes it soluble. With the amount of rain I get, elemental sulfur made my soil pH drop like a rock. Won't be doing that again. However, if you have excess sodium, calcium, magnesium or potassium in your garden soil, it's an effective way to leach it out.
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Post by steev on Apr 7, 2016 19:20:08 GMT -5
That's a good tip; maybe I can revert to my favorite gopher-killer: a lit road-flare, followed by a liberal supply of sulfur to drag the strontium down to where the gopher's been sent.
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Post by prairiegarden on Apr 7, 2016 22:39:07 GMT -5
I've used elemental sulfur in my garden before--it apparently gets converted to sulfate very quickly by microorganisms in the soil. And then immediately hooks up with any positively-charged mineral ions it can find (Calcium, Magnesium, Potassium, Uranium, whatever.) And makes it soluble. With the amount of rain I get, elemental sulfur made my soil pH drop like a rock. Won't be doing that again. However, if you have excess sodium, calcium, magnesium or potassium in your garden soil, it's an effective way to leach it out. That's an interesting thing to think about with so many acres of irrigated land beginning to have issues with " salted " soil. A lot of of it is getting close to being unusable, I wonder if sulfur would have any practical use to bring it back, and what affect it would have..and if anyone has tried that. All I've heard of them trying was to find some sort of plant that could survive or even thrive in heavily salted soil, not easy to find, even harder to find one that's also " useful". |
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Post by steev on Apr 8, 2016 1:37:24 GMT -5
Here in NorCal, the best example is the "Westlands" developments. With subsidized irrigation, many acres on the west of the Central Valley were put into agriculture. That was very selenium-rich soil, needing drainage to toxify other areas. In the current drought, those interests are bitching that they aren't getting enough water; they're among the least senior water-rights claims in the state; fuck 'em; they never should have been opened to Big Ag, in the first place.
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