Brassica Mix Nutrient Recommendations

[CedarSwamp]

Does anyone know the nutrient recommendations for a brassica mix? I can find the recommendations for turnips, but can't find anything for rape.

For example: according to our soil sample the nutrient requirements for oats is 40# N; 70# P; and 155# K. I understand our soil sample regarding what we have for nutrients in the ground, but not sure what levels I'm trying to amend it to for Lick Creek Brassica mix. That's the part of the equation I'm missing and can't seem to find anything in my food plots books or on websites for what the mixture requires.

I usually put on 300# 19-19-19, but still never understood what the mixture requires.

Thanks!

 

[FarmerDan]

I'm gonna make something up as I don't think it matters much. Greens need a little phosphorous and more potassium and nitrogen. You soil sample must have been low in P and K? Oats recommendation is for 70#P and 155# K along with 40# N? You can't go wrong with that. And you could probably get away with half the recommendation. pH is more important. It's Ok? I don't know if you understand? Without seeing your soil test results and recommendations I could just be barking at the moon. I'd guess the oats recommendation is for production. See, we don't do production. We just grow plants. In production, we're trying to achieve a maximum economic yield. Food plotting is much more forgiving. Deer will graze and eat some small percentage of the plant material available. So, why sweat it? Back to the production recommendation for oats. The recommendation assumes the oats and the straw will be harvested and carried away resulting in a loss of soil nutrients used by the plants (and carried away). Then, to be sure there are enough nutrients to grow the next crop, the recommendation adds some additional nutrients for soil reserves. You can't go wrong. It's a very imprecise science. You options are to do nothing. To add some nutrients, with nitrogen probably the most limiting (use N), or to go with the full recommendation which is really rather generic for brassicas and grains.

 

[CedarSwamp]

Farmer Dan,

Thanks for the response. My question isn't regarding understanding the soil sample results. I'm looking for what the recommended nutrient requirements are for a food plot brassica mix, not the recommended application rates.

Basically the equation is:
Nutrient requirements - nutrients in soil = Amount to fertilize

I just don't know the nutrient requirements to be able to solve for amount to fertilize. Next year we'll do the soil tests based on brassicas, but what we got just gave us corn, oats, and alfalfa.

Thanks

 

[FarmerDan]

Yes, I get it. Let's look at your equation. There are two variables and we don't know the values of either one. I don't see where you provided the soil test results and, for food plotting the nutrient requirements are unknown. In production agriculture, at assumed yields, we sorta know what we carry away in the harvest. In food plotting very little gets carried away, but we don't know the answer to the question because there's no scientific interest in the question. And, even if there was, the "carry-out" probably varies wildly. I would contented you soil have every nutrient in sufficient quantities to grow brassicas in food plots. The question is, how much fertilizer do you want to apply to cut the risk of the ascertain being wrong. The one sure thing is a little shot of nitrogen will do some good. Probably no less than the equivalent of 40 lbs per acre and no more than 70.

There's no one right recipe!

 

[CedarSwamp]

 

[FarmerDan]

Wow! Now I don't know where to start. And, I take back my statement that there's probably enough nutrients in the soil to grow a crop of brassicas in a food plot. You're going to hate me, but I have to start by questioning your soil sampling methods just be be sure what we are looking at above is really representative of you soils. How deep did you sample? How many samples per 'plot? How did you sample? Shovel and bucket?

Anybody else want to jump on this while i ponder over a couple cups of joe?

 

[bueller]

IF you are set on planting brassicas I would follow the recommendations shown for planting oats but add an additional 100 lbs of urea 46-0-0 three or four weeks after planting. I say IF because with your nutrients being so low you may want to consider building that soil yet by getting your p, k, and lime in the ground while you stick to crops like rye therefore increasing your om at the same time. Brassica would do much better next year if you get those levels up between now and then.

 

[Bowman]

From Paul Knox: http://www.outreachoutdoors.com/foodplots/brassicas/fertilizers-for-brassicas/

I am waiting for Farmer Dan after he has some coffee.

 

[FarmerDan]

I really don't know where to go with this. I don't what what kind of soil we're working with and I don't know where the OP calls home. Oh! I went back and looked at the test results and see Wisconsin on it. That's what I would have guessed. Look at the column headed "texture code." The only soil lab I could find using a texture code was WI. The test results use 2 & 3. After my coffee this morning I thought I found that a 2 was clay and 3 was a clay loam, But, now I can't find the reference.

Here's what I'd do, lacking more information:
1. Treat all plots the same. I'm assuming they are not big enough individually for prescription fertilizer blends. Up at the top you'll see "adjusted average" -- pH 6.4, OM 4.2%, Phosphorous 19 ppm and Potassium 67 ppm (parts per million). A six-inch layer of soil contains 2-million pounds.

2. Soil pH is OK at 6.4. Resample in a year to verify this test's results.

3. In year one, in the top three inches of soil, raise the phosphorus from 19 ppm to 60 ppm. And raise the potassium from 67 ppm to 120 ppm

4. In year two do the same.

5. Resample in year 3.

I think it takes split applications of P & K to distribute optimum levels in the top 6-inches, assuming no tillage. Or, dump it all down at once and take what you get.

For the brassicas this year, apply 60-40-60 equivalent per acre which is kinda' handy, depending on fertilizer source. If 19-19-19 is available, apply 350 lbs equivalent per acre. Without putting too fine a point of the calculation, a similar application the second year would be beneficial and sufficient.

Right now, nutrient levels are out of balance which makes a specific recommendation for brassicas sorta' irrelevant.

Wadda' ya' think? Sounds funky, doesn't it?

 

[CedarSwamp]

I didn't do the sampling this year, but we use soil sampling spuds or whatever you call them that are designed for soil sampling. We usually sample around 5 places in each plot and mix them together. Our two oldest plots are the two with the best soil. Some of the plots are brand new meaning they are in the process of being cleared and hope to get those done in a month or so. The plots 3 - 8 I'd expect to be low as they are all plots that have never been planted and some have only been planted for 1 to 2 years. Plots 1, 2, and 8 have been in production for a while.

We are Northeast WI and our soils have quite a bit of clay and we have very few sandy areas.

 

[CedarSwamp]

Farmer Dan,

What nutrient levels do you generally try to get your soils to when fertilizing for a brassica mixture?

I think I'll plan to do the 300# or 350# per acre of 19-19-19 on all the plots with maybe the exception of plots #1 and #2 which don't need at lot of P or K.

We generally have half our plots in cereal grain mix with clover and then the other half in brassicas. During the summer they are all in clover via frost seeding and fall seeded with the fall planting. Some of the new plots are pretty small and deep in the woods sonmay try to get some of those in perennial clover.

 

[FarmerDan]

Farmer Dan,

What nutrient levels do you generally try to get your soils to when fertilizing for a brassica mixture?

Now lemme get this straight
You put the lime in the coconut, you drank 'em bot' up
Put the lime in the coconut, you drank 'em bot' up
Put the lime in the coconut, you drank 'em bot'up
Put the lime in the coconut, you call your doctor, woke 'I'm up

 

[S.T.Fanatic]

There is a lot of variables other than the nutrient levels. If your ph is below 6.0 then you are going to need a lot more fertilizer. The same can be said for soils containing less than 2% OM.
They also like boron and sulfur which your test not unlike any other doesn't specify unless you request it.

Quick google search resulted in the following:

N=100# with an OM of 2-5% 120# if less than 2#

If soil is in the medium range (which yours is not) 20-30#P and 120#K

1# boron on sandy soils and 2# for other soil types

10-15# sulfur

(All fertilizer amounts are per acre requirements)

 

[CedarSwamp]

Thanks! That gives me at least a general idea for this year until we do new soils tests for a brassica mixture instead of the corn/oats/alfalfa like we did this year.

 

[jsasker007]

post #12=WHAT!?

 

[CedarSwamp]

Post #12 was Farmer Dan being frustrated with my responses and I don't blame him because I was missing some main points.

I sent the soil samples to our UW AgExtension Agent to see if he can convert the soil sample results to a brassica mixture. He would be familiar with our area and if there is no way to convert it then I'll just fertilize the best that I can this year and request the soil samples for brassicas next year.

 

[Honker]

http://learningstore.uwex.edu/assets/pdfs/A2809.pdf

Here's a document you might find helpful. Page 57 covers forage brassicas.

55 lbs/a of P to apply if your levels are "low"
175lbs/a of K to apply if your levels are "very low"

So you are looking at 290 lbs/acre of 19-19-19 and 200 lbs/acre of 0-0-60

 

[FarmerDan]

post #12=WHAT!?

Sometime you just gotta' have a sense of humor here....

 

[jsasker007]

I thought maybe I was the only one not getting the inside joke. Wouldn't be the first time.