Problem Food Plot ... Hi Phosphorus Levels an Issue?

[Tree Spud]

One of my fields has been very difficult to successfully grow anything consistently.

In reviewing the soil test, my phosphorous levels are very high. In researching, too much phosphorous and inhibit plants from nutrient uptake. I can plant, but plants seem to stall out. I have been trying to grow cover crops to increase the soil OM, but have had limited success. I am wondering if the hi phosphorous is the reason.

Below is the soil test. Would appreciate any comments on the test results and ways to address.

 

[Brian662]

Following..

Excessive P

I've been combing over some of my soil samples and all my samples in WI show that I have "excessive" levels of phosphorus in the soil. Is there something palatable to deer that I can throw in my fall blend which will use up a higher portion of that phosphorus than normal?

habitat-talk.com

 

[TreeDaddy]

pH seems low/normal

What about adding calcitic lime( NOT dolomitic) and rye?

If ph seems acceptable , then adding gypsum seems reasonable to address low Ca++ and high Mg++ in compacted soil

Hopefully, SD and Farmer Dan will comment

bill

 

[SD51555]

How have u been managing it? Spraying, tilling, compaction? High magnesium and low CEC is interesting.


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[FarmerDan]

At first glance 34 ppm P doesn't seem so excessive, Without more info it's hard to come up with a workable answer for your poor crop growth. Some soils just aren't very productive and there's little we can do to improve them. Lots of farmers think ground is ground but the money making guys recognize the impact different unamendable soil characteristics have on yields. For the moment let's assume P, free P, soluble P is overly abundant. Where did it come from? Soils are filled with tons of insoluble P released in small quantities by weathering and a few other chemical reactions caused when we add something to the soil. Do you use any manures or poultry litter?

How deep did you sample? I think I would do it again keeping the collection in the top3-inches. And, if your lab can do it, test for micro-nutrients. Then I would (well, I will get you to do it) dig some holes to examine the soil structure and topsoil depth. Also, look for the soil type on the NRCS Web Soil Survey and read what it says about your soil. Then, maybe plant legumes in those high pH fields. Legumes love them some P!

But, while your P level is labelled HIGH, I don't think it's excessive. Numbers over 100 ppm, now thats a P problem.

 

[Tree Spud]

How have u been managing it? Spraying, tilling, compaction? High magnesium and low CEC is interesting.


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SD ... Soil is not compacted. I used my Firminator to lightly disc (low angle), plant, and cultipack the seed. Have not sprayed this area as anything that grows, including weeds, will add some OM.

 

[Tree Spud]

At first glance 34 ppm P doesn't seem so excessive, Without more info it's hard to come up with a workable answer for your poor crop growth. Some soils just aren't very productive and there's little we can do to improve them. Lots of farmers think ground is ground but the money making guys recognize the impact different unamendable soil characteristics have on yields. For the moment let's assume P, free P, soluble P is overly abundant. Where did it come from? Soils are filled with tons of insoluble P released in small quantities by weathering and a few other chemical reactions caused when we add something to the soil. Do you use any manures or poultry litter?

How deep did you sample? I think I would do it again keeping the collection in the top3-inches. And, if your lab can do it, test for micro-nutrients. Then I would (well, I will get you to do it) dig some holes to examine the soil structure and topsoil depth. Also, look for the soil type on the NRCS Web Soil Survey and read what it says about your soil. Then, maybe plant legumes in those high pH fields. Legumes love them some P!

But, while your P level is labelled HIGH, I don't think it's excessive. Numbers over 100 ppm, now thats a P problem.

FD ... here is the soil map. The outer loop is classified as OsB - Oshtemo loamy fine sand, and inner loop as BmC2—Boyer loamy fine sand. I sampled the soil from field 1 about 5-6", using all of the soil for testing.

Field 2 was planted in CIR switch grass in 2017 and has done very well. Wanted some cover, screening, and bedding, but more importantly to build more organic matter in the soil.

I have over seeded with cereal rye, red & ladino clover this past weekend. Next spring I am going to try and plant 4010 peas.

 

[SD51555]

Did you put a shot of dolomitic lime on there? That looks like about a quarter acre. Spread a 500 pound 'rate' of gypsum on that plot. If you're fine sand, it won't take much to overshoot your calcium to magnesium ratio, so that's probably a good place to start and see how it reacts. If you really wanna do something cool, just do half with and half without and wait to see the difference.

 

[Tree Spud]

Did you put a shot of dolomitic lime on there? That looks like about a quarter acre. Spread a 500 pound 'rate' of gypsum on that plot. If you're fine sand, it won't take much to overshoot your calcium to magnesium ratio, so that's probably a good place to start and see how it reacts. If you really wanna do something cool, just do half with and half without and wait to see the difference.

It's actually 2.5 acres. What will the dolomitic lime do for the soil?

 

[SD51555]

It's actually 2.5 acres. What will the dolomitic lime do for the soil?

Don't put lime on. I'm wondering if you already put dolomitic lime on. If you're sandy and have high Mg, I wondering if you didn't put on a bunch of dolomitic to get to 6.6 pH. Dolomitic is around 2 parts calcium to 1 part magnesium. I'm saying to put some gypsum on to get your calcium up, and the sulfate will help your clovers get going. In a low OM soil, you're gonna have sulfate problems, and that'll dog your clovers.

 

[FarmerDan]

Don't put lime on. I'm wondering if you already put dolomitic lime on. If you're sandy and have high Mg, I wondering if you didn't put on a bunch of dolomitic to get to 6.6 pH. Dolomitic is around 2 parts calcium to 1 part magnesium. I'm saying to put some gypsum on to get your calcium up, and the sulfate will help your clovers get going. In a low OM soil, you're gonna have sulfate problems, and that'll dog your clovers.

I too wondered about a low sulfate problem. And I am left to wonder about the natural pH of your soil TD. If you are where I think you are liming will only do you harm.
Aren't assumptions great?

pH of soil parent rock/source
oranges are acidic
yellows and whites are near 7
Blues are alkaline

There are labels in the map relaying the pH in the area of the label.

 

[Ben.MN/WI]

I have some sections of sandy soil with similar organic matter and it can be a struggle to consistently grow crops there. Those areas just don't hold the moisture like the better soils do just 50 yards away.

I can't grow corn in these crappy soil areas, but I can grow soybeans and brassicas. Through trial and error, I've found that brassicas there tend to do best when planted into an area that was winter rye the year before that was sprayed a couple weeks before brassica planting. The winter rye eventually falls over and gives just enough shade to keep a little more moisture in the soil for the young brassicas.

 

[Tree Spud]

Don't put lime on. I'm wondering if you already put dolomitic lime on. If you're sandy and have high Mg, I wondering if you didn't put on a bunch of dolomitic to get to 6.6 pH. Dolomitic is around 2 parts calcium to 1 part magnesium. I'm saying to put some gypsum on to get your calcium up, and the sulfate will help your clovers get going. In a low OM soil, you're gonna have sulfate problems, and that'll dog your clovers.

Ok, got it. The farmer who leased the field about 9 years ago did put lime on, but I have not since then.

How much gypsum per acre?

 

[Tree Spud]

I too wondered about a low sulfate problem. And I am left to wonder about the natural pH of your soil TD. If you are where I think you are liming will only do you harm.
Aren't assumptions great?

pH of soil parent rock/source
oranges are acidic
yellows and whites are near 7
Blues are alkaline

There are labels in the map relaying the pH in the area of the label.
View attachment 68187

Without any towns or roads, hard to id were my property is at. Per above soil test, pH is 6.6 which should be a good thing.

 

[Tree Spud]

I have some sections of sandy soil with similar organic matter and it can be a struggle to consistently grow crops there. Those areas just don't hold the moisture like the better soils do just 50 yards away.

I can't grow corn in these crappy soil areas, but I can grow soybeans and brassicas. Through trial and error, I've found that brassicas there tend to do best when planted into an area that was winter rye the year before that was sprayed a couple weeks before brassica planting. The winter rye eventually falls over and gives just enough shade to keep a little more moisture in the soil for the young brassicas.

Thats part of my problem also. One half of area is southward facing slop. If we get a good start to the plants in spring, but not enough cover, the south side will quickly dry up because of the sun. I have very little thatch build up so with the sandy soil, moisture retention is a problem.

As I said, a good overseeding of WR, clover, chicory, and I am trying SD's recommendation of yellow sweet clover to build some thatch layer up.

 

[SD51555]

Without more data, I’m gonna make a guess so we don’t shoot off the other end of the spectrum. A 4.4 CEC is a really light soil, so you probably have low ppm numbers on calcium and magnesium. I’d try 500 lbs/ac of gypsum and then wait a year and see what happens.


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[FarmerDan]

I'm going to pile up a lot of stuff. Let's see how it turns out.
Bottom line for me is this - those two soil types make for severe limitations when it comes to growing stuff and I think you can work yourself to death and not give it much improvement.

Oh! I'm assuming we are working somewhere in Marquette County, WI? If not I'm going to be mighty embarrassed!

Earlier I provided a graphic of the natural, unamended soil pH for a big part of WI. The map below and to the right is the pH map clipped. Marquette County is the one with the acorn in the center. The map to the left is for verification. So, typically (there are always atypical situations), there should be no need for use of any type of lime. Yellows and blues originate from rock with pH 7 or greater. A look at the detail of the two soil types indicates a calcium carbonate saturation of 25%. See the descriptions for each of the soils. Continue below...



For more understanding I stole this from some web site. You will need to dig deeper if you want to know more.

What is the range of CaCO3 in soil?
In general the optimum total CaCO 3 for micro aggregate formation may not exceed 20%. The best Total and (A/T CaCO 3 %) for better aggregate stability is between 20 to 48% . The proper total calcium carbonate for better total heterotrophic aerobic bacterial activity is around 20%



The other problem has already been discussed - sandy soil. Both types in question are deep and well drained, much too well drained. The bucket is might big and has capacity for a lot of water...but it has a lot of holes in it.

This is an excerpt from the soil survey. Look at the limiting characteristic, the ksat which give the infiltration rate of the soil type.

BmC2—Boyer loamy fine sand, 6 to 12 percent slopes, eroded



OsB—Oshtemo loamy fine sand, 2 to 6 percent slopes

 

[bigboreblr]

Got any pictures of your plants you grew? Look up boron or zinc deficiency and what it looks like. Sandy soil can always be suspect for drought issues.

What weeds grow well in your area? Might be an insight to your issues.

I've had one or two bad gly spraying attempts due to rain / dew up at camp. I'm glad i did. Let the weeds build organic matter for you. Some of those weeds bury roots down over ten feet. LEt the weeds make a nice mat over the summer, then dump some rye in there and roll it and or mow it over. Golden rod, asters, strawberry, and sedge makes up most of my weeds. some stubborn small shrubs too.

Any history from these plots?

Boston plantain might a be a good soil builder for you, pretty drought resistant. Plantain grows in total junk sandy soil up at camp. Boston plantain is made for southern regions where other crops fail from drought.

 

[Tree Spud]

I'm going to pile up a lot of stuff. Let's see how it turns out.
Bottom line for me is this - those two soil types make for severe limitations when it comes to growing stuff and I think you can work yourself to death and not give it much improvement.

Oh! I'm assuming we are working somewhere in Marquette County, WI? If not I'm going to be mighty embarrassed!

Earlier I provided a graphic of the natural, unamended soil pH for a big part of WI. The map below and to the right is the pH map clipped. Marquette County is the one with the acorn in the center. The map to the left is for verification. So, typically (there are always atypical situations), there should be no need for use of any type of lime. Yellows and blues originate from rock with pH 7 or greater. A look at the detail of the two soil types indicates a calcium carbonate saturation of 25%. See the descriptions for each of the soils. Continue below...

View attachment 68242View attachment 68241

For more understanding I stole this from some web site. You will need to dig deeper if you want to know more.

What is the range of CaCO3 in soil?
In general the optimum total CaCO 3 for micro aggregate formation may not exceed 20%. The best Total and (A/T CaCO 3 %) for better aggregate stability is between 20 to 48% . The proper total calcium carbonate for better total heterotrophic aerobic bacterial activity is around 20%



The other problem has already been discussed - sandy soil. Both types in question are deep and well drained, much too well drained. The bucket is might big and has capacity for a lot of water...but it has a lot of holes in it.

This is an excerpt from the soil survey. Look at the limiting characteristic, the ksat which give the infiltration rate of the soil type.

BmC2—Boyer loamy fine sand, 6 to 12 percent slopes, eroded
View attachment 68248


OsB—Oshtemo loamy fine sand, 2 to 6 percent slopes
View attachment 68247

I'm aware of the limitations. Sandy soil is a pretty common soil conditions for farm fields in the area. I had leased the ag fields to a farmer several years ago and they were pulling 145 bu/acre of corn off these fields.

 

[SD51555]

I'm aware of the limitations. Sandy soil is a pretty common soil conditions for farm fields in the area. I had leased the ag fields to a farmer several years ago and they were pulling 145 bu/acre of corn off these fields.

I bet, given what you've shared so far, your farmer limed it long ago. I think you have options here, so long as you go into it understanding what you're really risking. Reclamation seed is pretty cheap, and a gypsum application at 1250 lbs over 2.5 acres isn't gonna break the bank. If you did gypsum in 31 - 40 lb menards bags:

$300 - gypsum
$60 - 3 bags rye
$50 - 5 pounds YSC
$70 - 5 pounds chicory
$70 - 5 pounds plantain
$30 - 2 pounds ragweed
$580 or $232/ac

Could also fling some balansa and wildflowers in there if you really wanna give it a go, but there's a basic framework for what I'd look at putting on. Adjust as needed for what you've got on hand and what you've already done.