Gypsum - Weed Trial

SD51555

5 year old buck +
Hot off the journey thru the new weed book, the big idea to wipe out my weeds is calcium. In this little experiment, I’m going to put out a hot rate of gypsum and a little more lime on my yard plot. It has already gotten about 3,000 lbs/ac of mostly lime and a little gypsum over the last 4 years.

Size: 1/10th acre
Target species: Burdock, brome grass, hairy vetch
Gypsum rate: 2,000 lbs/ac
(C) Lime rate: 1,000 lb/ac

All three of those weed thrive in low calcium soils. I think I’ve had some luck with other high rate apps of gypsum. I had small pockets of sedge grass in one of my plots and I was tired of spraying. I laid the gypsum in deep on the clumps, like a half inch deep in and around the edge. There’s no sedge there anymore. Is that economical? No, but there’s got to be a lower rate where that still works.


Sent from my iPhone using Tapatalk
 
Last edited:
I picked up my first batch tonight. I’m gonna treat two spots this weekend, and keep hauling it in until I get tired of it. I’m going to start on the two spots I have that are almost fixed.

I’ll hit my yard plot first and try to finish off the burdock and brome. I’ve got some sedge poking thru in my main plot where I hit it with high rates last time. There’s not much, but I want to blast it again and see if no can finish it.

088bfb59ded21835cc78c86f75be9c92.jpg


4aae66225a0a4d2b603264fd8993b682.jpg




Sent from my iPhone using Tapatalk
 
Where do you get gypsum? Pellets or dust?
 
I absolutely love gypsum!

Helps soften my clay ground, helps it hold moisture better, helps micronutrients break down better for plant use and helps negate any over nitrogen use.
It is very hard to over gypsum and adds a lot of benefit to the soil.

My use of it has been small scale in the yard for decades at the old house and in our orchards. It is the magic bullet for a lush yard....or plot.
Trouble I have now is the price jumped bad after Covid and I’ve got a three-acre new yard with heavy clay I would like to start treating annually for the next decade.
I need to get with my local co-op elevator and see if they could sell to me in bulk and hit my yard heavy in the fall somehow with a not too big spreader.
It takes a couple years for it to break down good enough to start benefiting the dirt and plant life.
 
I purchase gypsum pellets at Menards in 50 pound bags.

That’s where I get mine too. It also spreads fast when you’re going heavy.


Sent from my iPhone using Tapatalk
 
The menards gypsum I purchase is in pellet form, so it is very easy to spread.
 
How would I know if I should put down pellitized lime or gypsum or combination of both for pH control?
 
How would I know if I should put down pellitized lime or gypsum or combination of both for pH control?
If you need to raise pH, use lime. Gypsum is for raising calcium without changing pH.

I would make a lime rec all on it's own and do that first. If you've got a pH reading already, and a buffer pH reading, we can make a lime rec for ya here.
 
Calcitic lime would provide the highest boost of calcium as it can be in the mid 30% range for calcium content depending on the source material. Gypsum hovers around 20-22% calcium content. But if you don't wanna move your pH, you're stuck with gypsum to add calcium. The sulfate in gypsum adds a lot of value too though.
 
Trying to understand what is "high or low" calcium content. I did some soil tests in spring.....and my PH runs about 6 and the buffer index is 7.

The calcium is 690 ppm, CEC is 4.5, Ca73.7, Mg23.5, K 2.7. Sulfur is Low. Magnesium is 130.

Not sure what those values represent.

Would calcitic lime be what I need? I considered getting a load this spring (price was about $600 for 23 tons delivered.
 
Trying to understand what is "high or low" calcium content. I did some soil tests in spring.....and my PH runs about 6 and the buffer index is 7.

The calcium is 690 ppm, CEC is 4.5, Ca73.7, Mg23.5, K 2.7. Sulfur is Low. Magnesium is 130.

Not sure what those values represent.

Would calcitic lime be what I need? I considered getting a load this spring (price was about $600 for 23 tons delivered.

When I get settled tonight, I’ll get out the chart and a link for ya.


Sent from my iPhone using Tapatalk
 
Trying to understand what is "high or low" calcium content. I did some soil tests in spring.....and my PH runs about 6 and the buffer index is 7.

The calcium is 690 ppm, CEC is 4.5, Ca73.7, Mg23.5, K 2.7. Sulfur is Low. Magnesium is 130.

Not sure what those values represent.

Would calcitic lime be what I need? I considered getting a load this spring (price was about $600 for 23 tons delivered.

Without looking, I can tell you you’re looking at 1/2 to 3/4 ton/ac to hit 6.5 pH. And yes, calcitic is what you want. I’d want to see their lime analysis before you buy. If it’s the same outfit as last time, they brought you dolomitic.


Sent from my iPhone using Tapatalk
 
Without looking, I can tell you you’re looking at 1/2 to 3/4 ton/ac to hit 6.5 pH. And yes, calcitic is what you want. I’d want to see their lime analysis before you buy. If it’s the same outfit as last time, they brought you dolomitic.


Sent from my iPhone using Tapatalk
No different outfit. I could have had either last time......and really did not know what I needed. I chose the dolmetic.

This guy wanted a soil test before he would sell me lime. (a good sign) He says most around here spread the calcitic lime. I may try to get a load brought in this year....and spread it when I can. With my spreader, I can spread an entire load if I put in a full day.
 
Here is a 1/2 truckload of lime for free....near Little Falls MN. You gotta load and haul yourself. Could be a good deal if you are located near by.

 
No different outfit. I could have had either last time......and really did not know what I needed. I chose the dolmetic.

This guy wanted a soil test before he would sell me lime. (a good sign) He says most around here spread the calcitic lime. I may try to get a load brought in this year....and spread it when I can. With my spreader, I can spread an entire load if I put in a full day.
Here's the link to the lime rec chart:


You're looking at a half ton/ac to go from 6.0 to 6.5 pH.

Foggy.PNG
 
Can you spread that stuff with a cone fertilizer spreader?
easily

spreads like pelletized lime

I buy mine at Atwoods

bill
 
I got the first load of gypsum down this weekend.

Yard Plot: 1-ton/ac rate. Weeds I'm going after are burdock, catchfly, brome grass, quackgrass.
North end SPC: 1-ton/ac rate. Weeds I'm going after are curly dock, canary grass.

Next weekend, I think I'm going to go after my Road Plot. That's where the YSC thread lives. Out there, I've got hemp nettle and oxeye daisey. I used to get hemp nettle in my raised bed gardens pretty bad. I spread gypsum on them a few months ago, and pretty heavy. I haven't hardly pulled any hemp nettle since. I've had a lot of rain to wash that in too.
 
Top