Soil fundamentals library
- Thread starter SD51555
- Start date
SD51555
5 year old buck +
@Brian622
Pigweed is called to action by us like every other superweed. They are 'response to what we just did' weeds. The more you try to kill them and till them, the stronger they get. Understand that they thrive where death happens. Soil death destroys mycorhizal fungi (MF) through starvation (spraying) or predation (tillage) by bacteria. All the good plants need MF networks to solubolize and deliver nutrients into the plant. The super weeds are all very weak plants in reality. The reason they do so well is they are uniquely adept at accumulating nutrients without the help of MF.
These weeds always follow the same catalyst: death.
You can (and always will) have super weed seeds in your seedbank by the billions per acre and can do just fine. All natural seeds have 'resistance to germination' mechanisms. These are intelligently designed traits that enable these seeds to endure for decades waiting for just the right moment to spring forward and restock the seed bank. Those signals are changes in organic acids in the soil. Those are driven by pH changes, mineral changes, death, flooding, drought, grazing, shift in plant makeup, etc. Death is the big one that calls up these monsters. If you stop the catalyst that calls them up, they will go back to sleep.
@Foggy47 has a great story about laying down his guns with pigweed, and he won.
Pigweed is called to action by us like every other superweed. They are 'response to what we just did' weeds. The more you try to kill them and till them, the stronger they get. Understand that they thrive where death happens. Soil death destroys mycorhizal fungi (MF) through starvation (spraying) or predation (tillage) by bacteria. All the good plants need MF networks to solubolize and deliver nutrients into the plant. The super weeds are all very weak plants in reality. The reason they do so well is they are uniquely adept at accumulating nutrients without the help of MF.
These weeds always follow the same catalyst: death.
You can (and always will) have super weed seeds in your seedbank by the billions per acre and can do just fine. All natural seeds have 'resistance to germination' mechanisms. These are intelligently designed traits that enable these seeds to endure for decades waiting for just the right moment to spring forward and restock the seed bank. Those signals are changes in organic acids in the soil. Those are driven by pH changes, mineral changes, death, flooding, drought, grazing, shift in plant makeup, etc. Death is the big one that calls up these monsters. If you stop the catalyst that calls them up, they will go back to sleep.
@Foggy47 has a great story about laying down his guns with pigweed, and he won.
BrushyPines
5 year old buck +
I feel his pain. Sunn Hemp has done well for me. Going to give Alyce clover and Joint vetch a try next spring.
davidhelmly
5 year old buck +
That has been a great combo for me, especially on newly established plots.
farmlegend
5 year old buck +
Took delivery yesterday and plowed through most of it!I’ll type up notes in a second.
Sent from my iPhone using Tapatalk
An I understanding this correctly - if a plant is listed as VL in the Ca column, does that mean it thrives under very low calcium conditions, and that adding calcium may cause it to diminish?
SD51555
5 year old buck +
Exactly. Go find your top ten weeds and you’re gonna find your common issue. It’ll jump right off the page.
Sent from my iPhone using Tapatalk
Foggy47
5 year old buck +
Alas, I need to spend some time with this book.
farmlegend
5 year old buck +
As you might have guessed, my problem plants have VL’s across the board.
SD51555
5 year old buck +
As you might have guessed, my problem plants have VL’s across the board.
What’s your common VL element?
Sent from my iPhone using Tapatalk
farmlegend
5 year old buck +
Ca, consistently. Should have said that!
Thistles, foxtail, nutsedge, MF rose, common burdock, chickweed, wintercress, and many more.
Have to do some searching for bulk gypsum. Called my local ag fertilizer operation, they reacted as if I'd asked for a load of plutonium. They said they could probably get it but it would be minimum 25 tons, IOW slightly more than I need.
SD51555
5 year old buck +
I’d get a high quality soil test before you head down that path. You want one that does a full base saturation test, ppm of all your minerals (calcium and magnesium being the big ones), and buffer pH and CEC.
The S3C test at Midwest labs will hit all those. Probably $30 and a little paperwork. But it could help you right size your calcium target and save you a ton of money.
Sent from my iPhone using Tapatalk
farmlegend
5 year old buck +
SD51555
5 year old buck +
Ok, that’s a good test.
My rough math shows you could go as high as 5,000 lbs gypsum over maybe three years. I’d be cautious about putting too much on at once on a large scale on sandy soil because you can’t pick it up after it’s down.
So I’d break it up over three years, and if u see improvement after the first third, you can pump the breaks before doing a bunch more u may not need.
If u want my goofy math on how I arrived at that, I can share it.
Sent from my iPhone using Tapatalk
farmlegend
5 year old buck +
I would be very interested in seeing your “goofy math”!
Whe you get some time, no rush.
SD51555
5 year old buck +
Your calcium to magnesium ratio is very close to 4.5:1 (900 ppm to 187 ppm). There is no agreement on the relevancy of Calcium to magnesium ratios. I subscribe to it because when it’s out of whack, it usually presents other management challenges.
You don’t want to go higher than 10:1, so because you’re in sandier soil, let’s shoot for around 7:1 or 8:1. That means you’d have to raise your calcium ppm to around 1500. Gypsum is around 20% calcium. To raise up to 1500 ppm, you’d need 600 ppm Ca, 600 ppm Ca is 1200 lbs.
1200 lbs @ 20% calls for 6,000 lbs/ac gypsum. That’s a lot. Let’s round down to 5,000 and split it into 1/3 each year for 3 years. 1500-1600 lbs/ac is a good shot and I’d want to see what happens for a season. Again, once it’s down, you can’t pick it back up.
Sent from my iPhone using Tapatalk
You don’t want to go higher than 10:1, so because you’re in sandier soil, let’s shoot for around 7:1 or 8:1. That means you’d have to raise your calcium ppm to around 1500. Gypsum is around 20% calcium. To raise up to 1500 ppm, you’d need 600 ppm Ca, 600 ppm Ca is 1200 lbs.
1200 lbs @ 20% calls for 6,000 lbs/ac gypsum. That’s a lot. Let’s round down to 5,000 and split it into 1/3 each year for 3 years. 1500-1600 lbs/ac is a good shot and I’d want to see what happens for a season. Again, once it’s down, you can’t pick it back up.
Sent from my iPhone using Tapatalk
farmlegend
5 year old buck +
Great, thank you!
Would it be accurate to say your assumption that my ground is "sandy" is because of the cation exchange score?
Most everyone who has toured my ground has remarked at how "clayish" it seems. It is quite greasy when wet and I've gotten my 4WD tractor with R1 tires stuck in it. The dominant soils on my farm are, according to the USDA soil maps, WIlliamstown-Conover Complex and Miami clay loam.
Unless my sampling methodology was flawed and my soil probe just hit the wrong spots. Or I just have the tightest sands around.
Last edited:
