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translating soil test results

Posted by a_bear TN (My Page) on
Fri, Jun 18, 10 at 15:16

I'm trying to begin an organic program with my lawn, and I just got back my soil test results.

They recommend using in early fall one of the following fertilizers:
16-4-8 (6.2 lbs)
18-2-18 (5.5 lbs)
18-2-9 (5.5 lbs)
21-8-12 (5 lbs)
22-4-14 (5 lbs)
24-5-11 (4 lbs)
28-3-6 (3.6 lbs)

in concert with one of these in spring and late fall:
34-0-0 (1.75 lbs)
30-3-4 (1.75 lbs)
28-3-3 (1.75 lbs)
29-3-4 (1.75 lbs)

In my area I don't have a ready supply of commercial organic fertilizers. All I have right now is a sack of soybean meal picked up from a farm supply store.

Are there other organic materials that can be used to achieve similar ratios?

Follow-Up Postings:

RE: translating soil test results

By running a few numbers it looks pretty clear that they're aiming their recommendations directly at nitrogen. All of the fertilizers and rates in the "early fall" recommendation give about 1 lb. of actual nitrogen while all of the "spring and late fall" recommendations result in about 1/2 lb. of actual nitrogen.
Go ahead and post the actual test results and I bet we can come up with something a tad more meaningful for you.

RE: translating soil test results

By the way. Your soybean meal could be used at at 15 lbs. per 1000 sq. ft. and 7 lbs. per 1000 sq. ft. respectively to meet the "early fall" and "spring and late fall" fertilizer recommendations that were provided by the lab's FertilizerRecommendations-O-matic!.

RE: translating soil test results

Those recommendations are typical of what is suggested for "conventional" lawns and probably do not really apply, or translate into organic lawn care. How much area is suggested for the application of these "fertilizers"? Usually you see apply X pounds of X-X-X per X,000 square feet.
Without knowing what the soil test results actually were anything would be a very wild guess.
What is your soils pH?
What is your soils nutrient levels?
What did the soil test report say about CEC, Calcium, Magnesium?

RE: translating soil test results

Thanks for the help! Here are the rest of the numbers:
Water pH: 6.6
Buffer value: 7.6
P: 33 H
K: 309 H
Ca: 5376 S
Mg: 842 S
Zn: 43.2 S
Cu: 1.8 S
Fe: 6 S
Mn: 223 S
B: 2.3
Na: 25

The recommendations are per 1,000 square feet.

RE: translating soil test results

The pH is right on the money, so no worries there. Your phosphorous and potassium look more than ample for turf grass for this year. I would stick with a nitrogen only fertilizer for the rest of this season. That can be applied in response to the appearance and growth of the grass. If it looks like it needs an immediate application, go for it.

........"I don't always apply nitrogen only fertilizers but when I do, I apply blood meal."

When you apply bloodmeal, a good rate is 10 lbs. per 1000 sq. ft. and make sure to water it in. That material should provide sufficient nitrogen for about 60 to 90 days.Consider re-testing next spring. I would imagine that the grass could probably use some phosphorous at that time. That would be a good time for your soybean meal at about 15 lbs. per 1000 sq. ft. It doesn't supply much potassium, but I'm thinking you may not need potassium next year either.

Also, I'm not sure what their 'S' means but iron looks a little low to me. I like to see it closer to 15 to 20 ppm. If your turf is yellow but does not respond to nitrogen fertilization, it may respond to iron.

RE: translating soil test results

If you take that 6.2 pounds of product per 1,000 square feet you would be applying 0.006 pounds per square foot, a pretty minimal amount of anything. So none of those suggested things are necessary and the results of your soil tests look pretty good, except the pH is a bit high (optimum is in the 6.2 to 6.8 range). Iron, a micronutrient, may not be as available as desireable because of that higher than optimal pH which helps keep Iron availability lower.
What is the level of humus in your soil? if that is not around 6 to 8 percent consider doing what you need to do to raise that level.

RE: translating soil test results

What about beet molasses? That's high in nitrogen and iron, isn't it?

RE: translating soil test results

Maybe the farm supply will have bloodmeal too.

They left the "organic matter %" blank, which must mean that was something separate I was supposed to ask for. I assume that's what you mean by humus. My guess, though, is that it's not great. I have very hard-packed clay, but I'm not sure what one can judge by the naked eye.

So are you saying, kimmsr, that you feel no fertilizer is necessary?

RE: translating soil test results

Try these simple soil tests to learn more about the soil you have,
1) Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

These tests will help answer more of your questions, but yes I don't think there is any good reason for you to spred any of those "fertilizers". If you think you could spred Blood Meal at a rate of 0.01 pounds per square foot you could add that. Is there any reason why you think you need to fertilize this lawn?

RE: translating soil test results

I'll give this a try, thanks.

I assumed it needed to be fertilized because the results of the soil test told me it did. This is all new to me. I'm here to learn.

RE: translating soil test results

As I stated, no. You won't need phosphorous or potassium. But you will need to provide some nitrogen during the growing season. And your pH is just fine at 6.6. As (again) I already stated, if you have a micronutrient deficiency problem, it's going to be low iron, since it's lower than your grass likes. You can follow my advice and be just fine or you can spin your wheels listening to the guy that thinks buffer value and pH are the same thing (Here's a hint: they're not).

RE: translating soil test results

Great, thanks.

To be clear, I was trying to say that I came _here_, to the forum, assuming I'd need fertilizer because the test said I did. When I responded to kimmsr about him not recommending fertilizer, I meant just the nitrogen you, gargwarb, had been talking about. I was just trying to understand whether or not there was disagreement between you about nitrogen fertilizers. I'm not looking to return to the test's recommendations.

In any case, what's a good source for iron?

I appreciate all the help.

RE: translating soil test results

Few labs test for Nitrogen anymore because they have learned that Nitrogen availability is very soil temperature (ie. bacterial activity) dependant. As a common practice these labs will give some numbers for Nitrogen, based on the experience they have with people trying to grow anything in sick soils devoid of organic matter. If your soil has ample organic matter there more than likely would be little need to add Nitrogen during the growing season, that make the soil into a good healthy soil that will grow strong and healthy plants thing.
If you work on and make your soil good and healthy then the Soil Food Web will provide what nutrients your plants need when they need them.

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