Tumbledown Farm’s Soil Testing, Soil Fertility, and Organic Fertilizer Page

"It is the first business of every farmer to reduce the fertility of the soil, by removing the largest crops of which the soil is capable; but ultimate failure results for the landowner unless provision is made for restoring and maintaining productiveness. Every landowner should adopt for his land a system of farming that is permanent,--a system under which the land becomes better rather than poorer."--Hopkins

"Many poor farmers have a lazy faith in the Lord; they think or hope that He will somehow make up for whatever they fail to do."--Hoard.

As quoted by Cyril G. Hopkins, in the "Introduction" to Soil Fertility and Permanent Agriculture

Soil Testing Process

Tumbledown has avoided having his soil tested now for the better part of four years. That's the equivalent of gambling with the life of your garden. And why has Tumbledown been so negligent? It isn't because he is ignorant of the need for a chemical analysis of the soil or the importance of N-P-K and pH and various trace elements for growing plants. But for the novice, finding an easy way to get your soil tested can be quite a challenge. When you ask for help with soil testing at the local nursury or feed and seed , the clerk either points to the aisle with the little play-toy soil test kits (which, even when done right, can tell you very little with precision--and Tumbledown is no chemist), or nods knowingly and says, "contact the extension office," by which she means the local, county office of the "cooperative extension service." In Tumbledown's case that means the Purdue University (land-grant university) cooperative extension office. [Note: This is NOT the same as the Soil and Conservation District, which sent Tumbledown on a wild goose chase, calling every registered soil scientist in Indiana. A "soil scientist" can tell you whether you can install a septic tank, not whether you can grow a garden!]

The County Extension Office:

http://www.ces.purdue.edu/marion/

Purdue University Cooperative Extension Service
Marion County Office
6640 Intech Blvd., Ste. 120
Indianapolis, IN 46278-2012
marionces@purdue.edu

Phone: 317/275-9305
Fax: 317/275-9309

Tumbledown will eventually make his way to this mysterious office (once well known to every farmer and gardener worth his salt) to check out the services they offer. In the meantime, he encountered a helpful Master Gardener (one of these days Tumbledown will become a Master Gardener--now there's an oxymoron). This very helpful gardener suggested that Tumbledown could skip the "county fair" extension office and go straight to the laboratory with his soil. So, that's what Tumbledown has done. You can check back here for the results next week. (According to the woman on the phone, it only takes three days, and they e-mail the results!) With the right soil amendments in place, Tumbledown's garden will grow strawberries the size of your big toe and tomatoes the size of softballs!

After all his procrastination, Tumbledown can hardly believe that it is so easy!

tools for collecting a soil sample

1) Dig a "v"-shaped hole 6-8 inches deep with the garden trowel, then slice off a 1-inch side of the hole, so that you get a 1" X 4" X 6" slab of dirt.

soil sample

2) Repeat the sample several times in different locations.

3) Mix the samples thoroughly in a plastic bucket.

4) Put two cups of the mixed soil in a ziplock bag and label with a sample identification number.

[Repeat the process for radically different parts of the garden. In Tumbledown's case, this means that the sloping hill is treated as one soil type and the low-lying easement as another.]

5) Place the ziplock bags in a box and mail to the lab with an order form, indicating what sort of plant you intend to grow and what sort of test you want ("basic" = organic matter, phosphorus, potassium, calcium, magnesium, CEC pH and lime index; "complete" = organic matter, phosphorus, potassium, calcium, magnesium, sodium, CEC, pH, lime index, conductivity, boron, copper, iron, manganese, sulfur, and zinc).

The tests run $15.00 for basic and $25.00 for complete.

The laboratory that Tumbledown will use was recommended by the Master Gardener with whom he spoke:

A & L Great Lakes Laboratories, Inc.
3505 Conestoga Drive
Fort Wayne, Indiana 46808-4414
Phone: 260-483-4759
Fax: (260) 483-5274

http://algreatlakes.com/

Tumbledown has since discovered and received recommendations regarding two additional regional laboratories for soil testing and analysis:

Midwest Laboratories
13611 "B" Street
Omaha, NE 68144
Phone: (402) 334-7770
https://www.midwestlabs.com/index_ssl.html

Texas Plant & Soil Lab, Inc.
[FM 1925, 3 1/2 MI WEST OF US 281]
5115 W. Monte Cristo Rd.
Edinburg, TX 78541
Phone: (956) 383-0739
FAX: (956) 383-0730
http://www.txplant-soillab.com/index.htm

Soil Test Results

Tumbledown received his results from A&L Great Lakes Laboratories via e-mail on May 31, 2007. He will continue to report annually on steps taken to improve the soil and what crops are grown, and compile a history of the results as revealed by future soil tests.

Here is the baseline for comparison:

Soil Sample #1, the North-Facing Slope (complete analysis)

Element	Amount Found	Rating
Organic Matter, %	2.6	Medium
Phosphorus, ppm P	26	Medium
Potassium, ppm K	137	Medium
Magnesium, ppm Mg	290	Medium
Calcium, ppm Ca	3750	Very High
Sodium, ppm Na	25	Very Low
Cation Exchange Capacity, meq/100g	21.6	High
pH	7.9	Very High
Soluble Salts, mmho/cm	0.2	Very Low
Sulfur, ppm S	15	High
Zinc, ppm Zn	3.4	Medium
Iron, ppm Fe	14	High
Manganese, ppm Mn	60	Very High
Copper, ppm Cu	1.3	High
Boron, ppm B	0.7	Medium

Annual Nutrient Requirement per 100 Square Feet for Vegetable Garden on North-Facing Slope:

Lime 0.0
Nitrogen (N) 0.4
Phosphorus (P205) 0.5
Potassium (K20) 0.4
Magnesium (Mg) 0.0
Sulfur (S) 0.1

A&L's Suggested Fertilizer Application (non-organic):

12-12-12 NPK Complete Fertilizer at a rate of 3.6 lbs per 100 square feet.

Soil Sample #2, the Low-Lying (wet) Easement (basic analysis)

Element	Amount Found	Rating
Organic Matter, %	4.0	Medium
Phosphorus, ppm P	87	Very High
Potassium, ppm K	140	Medium
Magnesium, ppm Mg	325	High
Calcium, ppm Ca	2300	High
Cation Exchange Capacity, meq/100g	14.6	Medium
pH	7.8	Very High

Annual Nutrient Requirement per 100 Square Feet for Vegetable Garden on Low-Lying (wet) Easement:

Lime 0.0
Nitrogen (N) 0.4
Phosphorus (P205) 0.1
Potassium (K20) 0.3
Magnesium (Mg) 0.0
Sulfur (S) 0.0

A&L's Suggested Fertilizer Application (non-organic):

18-10-18 NPK Complete Fertilizer at a rate of 2.2 lbs per 100 square feet.

Restoring and Maintaining Soil Fertility: Permanent, Organic Agriculture

The first question to cross Tumbledown's mind (like a 2X4 between the eyes) was the question of sustainability. What is required in order to continue cultivating this .9 acreas (give or take an acre or two) permanently? The question is usually asked in terms of wider environmental concerns, but--not to put too fine a point on it--sustainability also means the difference between success (livelihood) and failure (bankruptcy) for the individual farmer. As the Roman farmer Cato once said, a farmer "should have the selling habit, not the buying habit" (Cato, On Agriculture, II.3) ...and fertilizer (at $20 per bag retail) can become a buying habit. The question, personally, is whether it costs more to maintain the fertility of the soil than it is worth in additional, higher quality produce. Is the cost greater than the value of the food produced? This is partly subjective, a matter of valuation. (What is organic produce worth to you?) It is also partly a matter of accounting. What does it cost to maintain soil fertility organically? We will attempt to answer the latter to the best of our ability (with your help) and leave the former, more subjective evaluation to you.

There are "cheap' fertilizers (and Tumbledown would never call the synthetic chemical fertilizers cheap, no matter how inexpensive they may be). In other words, there are less expensive routes to increased fertility, though they take patience, like the planting of legumes, the composting of wastes, and the spreading of manure. Already in Roman times (and before), it was clear that some crops fertilize the ground in which they grow and that composting plant remains and spreading manure all benefit a field. ( Cato / M. Catonis, De Agri Cultura, XXXVI-XXXVII, recommends the spreading of "pigeon, goat, cattle" and other dungs; the planting of "lupines, beans, vetch"; and the composting of "straw, lupines, chaff, bean stalks, husks," etc.) We will explore these ways of maintaining fertility in the months and years ahead, but for now, for ease of calculation and immediate need, we will make the assessment in terms of packages taken from the store shelf: N (blood meal; Whitney Farms, Scotts), P (bone meal; Whitney Farms, Espoma), and K (greensand; Espoma, GreenSense, Fertrell)

Organic Matter and pH, medium and high

Since the pH of Tumbledown's soil is very high (7.8-7.9) and the % of organic matter in the soil is only medium (2.6-4.0, as is the case with many relatively new suburban lawns), Tumbledown will incorporate Sphagnum Peat Moss (pH 3.5-4.0) into the soil at a rate of 2 lbs per square foot annually, until the pH reaches 6.5 and the % of organic matter reaches a more uniform 4-5. Concerned that this approach may harm the environment? It seems better to Tumbledown than the alternative, an application of sulphur, which only addresses pH. See the National Sustainable Agriculture Information Service (this is a page on all sorts of seed starting materials, but scroll down to the section on Sphagnum) for answers to questions about the environmental impact of the use of Canadian Sphagnum peat, and see the 55-page pdf document from the Organic Materials Review Institute (OMRI) for a full list of organic fertilizers and soil amendments.

Planting tomatoes while amending the soil with Sphagnum peat moss

Planting tomatoes while amending the soil with Sphagnum peat moss

Tumbledown uses Ferti-Lome® Pure Canadian Sphagnum Peat Moss (Lambert Peat Moss, Inc.) in the "brick" (5.5 cu ft. pictured above) which is untreated--i.e., it hasn't been contaminated with commercial wetting agents. Tumbledown will also continue to mulch heavily with straw (5.59 for the super bale) and with pine needles, the latter not purchased at $8.99 per small bale, but collected from his own trees and spread primarily where the strawberries are planted. He will also continue to incorporate manure (rabbit and cow manure provided by a friendly farmer) and compost as they are available in order to increase the percentage of organic matter in the soil.

Application:

The peat moss will be tilled into the soil as the seed bed is prepared every year, but this will obviously not take place 1/4-1/6 of the time, depending on whether the rotation is a 4-, 5-, or 6-year rotation. (The ground is not tilled in years when winter wheat is followed by red clover, or for two years when winter wheat is followed by alfalfa.)

Annual Cost:

       Sphagnum, $19.99 / 5.5 cubic foot
       Straw Bale, $5.59 / large (super) bale
       [Pine straw, $8.99 / small bale]
       (Comparison, non-organic Sulfur, $4.99 / 4 lbs.

Phosphorus (P), medium-very high

The two areas tested varied greatest in the level of Phosphorus available in the soil: the low-lying, poorly drained easement tested at 87 parts per million (ppm) and the slope at 26 ppm. This means that Tumbledown will incorporate Bone Meal into the soil annually at a rate of .022 lbs per square foot (or .88 lbs per 20 foot row) in the easement and at a rate of .05 lbs per square foot (or 2 lbs per 20 foot row) on the slope.

Application:

1/2 the total amount will be tilled into the soil annually at the time of seed-bed preparation (see the exceptions above for years in the rotation when the soil is not tilled), with the other half side-dressed at cultivation.

Annual Cost:

Bone Meal, 0-10-0, $9.99 / 20 lbs.
(Comparison: Non-organic Super Phosphate, 0-18-0, $3.99 / 4 lbs.)

Potassium (K), medium

The two areas tested at 137-140 ppm of Potassium. This appears to be the most difficult (and expensive) aspect of soil fertility to maintain organically, given the .1% of Potassium immediately available upon application per pound of Greensand applied. In other words, a 40 lb bag of Greensand applied to 100 square feet of garden yields .04 lbs of Potash immediately available per 100 square feet, whereas the annual nutrient requirement is 8-10 times that amount, or .3-.4 lbs per 100 square feet. At $20 per 40 lb bag, that's $200 per 100 square feet of garden space per annum. That's clearly not an acceptable cost. This requires more study!

Annual Cost:

       Green Sand, 0-0-.1, $8.99 / 10 lbs.
        Green Sand, 0-0-.1 $19.95 / 40 lbs.
       (Comparison: Non-organic Muriate of Potash, 0-0-60, $4.99 / 4 lbs.)    [This is a yield of 2.4 lbs of Potash for $4.99, vs. the Green Sand's .04 lbs of Potash for $19.95. No wonder organic gardeners routinely fall off the wagon and go over to the synthetic chemical dark side for "just a little" Potassium fix.]

Nitrogen (N), ?

The question mark is there because A&L does not list the element and apparently did not test for it, though they do recommend the application of Nitrogen at a rate of .4 lbs per 100 square feet. Intriguing to Tumbledown is the relative analysis and potential of plain old urine as a fertilizer. Urine begins with a pH of 6-7, but the pH rises rapidly as it ages to more than 9. At a pH of 9, it only compounds Tumbledown's pH problem, so if urine were applied for the sake of a cheap (free, sustainable) nitrogen boost, it would be fresh (less than 24 hours), diluted, and only applied at the base of fruiting plants (not to edible roots) a month or more before consumption. (See the World Health Organization guidelines for developing countries.) Undiluted urine has the following chemical composition (approximately; it varies with person, diet, condition):

N (tot)	NH4*	P (tot)	K*	pH
6.7	0.4	0.5	1.8	8.1

The use of separated urine as mineral fertilizer, poster by Jürgen Simons*, Gitta Schirmer**, Joachim Clemens*
Fertilizer from the Library, by Marcus Boller

Annual Cost:

Blood Meal, 12-0-0, $5.99 / 2.75 lbs.
Urine, (analysis above, in Kg), free.

Clearly, there is more analysis to come!

Bibliography:

For more information on soil fertility, see our library, especially the book by Cyril G. Hopkins, Soil Fertility and Permanent Agriculture. Another easily accessible and more recent book (from an organic gardening perspective) is Gene Logsdon's Gardener's Guide To Better Soil.

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