Logan Labs Soil Test Results advice - high phos., low nutrients
Hi all, I'm looking for some collective wisdom regarding the results of my soil test. I've been reading the various soil test threads and want to be sure I'm on the right path.
A little background: I'm new to this property. It's a small, shady backyard in a semi-urban area (houses fairly close together, concrete driveway and paths, a parking lot behind the fence in the back). Last fall I put in some grass after clearing out the weeds & overgrowth. I tilled in some compost prior to seeding and followed a basic fertilization schedule: starter fert. and rapid-lime (calcitic) at seeding (I used a Rapitest litmus test to guesstimate pH), half-rate of starter fert about a month later, then a final high-nitro winterizing fertilizer before the winter. I haven't added anything to the Lawn since then. I have kelp/humic sprays, compost tea, and SBM on deck but I was waiting to see the results of the tests first.
The Test Results
I also sent three other samples to Logan for the plant beds that surround the Lawn. The Lawn test results are highlighted in yellow:
If this is hard to read (houzz seems to shrink all images), you can see a full-size version here
My Interpretation
1. pH - I knew the soil was acidic (judging by the Rapitest) but was surprised to see it this low in the lawn area, especially as I had limed it last fall though at less than bag-rate (I wasn't sure how much or how fast it would impact pH). The azaleas & rhododendron will be happy.
2. EC & OM - These seem to be some of the few positives. The ECs echo my soil jar tests - silt loam to loamy sand, but mostly sandy loam.
2. P - The high phosphorus was alarming but from what I've been reading in other threads there isn't much to be done other than to avoid more phosphorus.
3. Low nutrients (Cal, Mag, K) - Not really surprised with this as I'm not sure how much maintenance the previous owner was doing (other than dumping high-P fert. on his flower beds) and the nature of the surrounding area.
4. High heavy metals (esp. Cu, Zn, Al) - A bit disconcerting but also not surprising (parking lot runoff? water supply? NJ acid rain?). From what I've read in other threads, the high Aluminum seems to be common in the Northeast. There doesn't seem to be much that can be done here either other than to avoid adding more of these elements. The iron level appears to be fine, though I presumably shouldn't be adding more. Boron & manganese deficiencies will need to be addressed.
What To Do/My Conclusions/Questions
Not the most favorable test results, but I'm hoping the issues can be remedied without too much pain.
From what I've gathered from other soil test threads, the options include:
- Do regular applications (2-3x per year) of dolomitic lime at max bag-rate to bring up the pH and increase Cal & Mag levels (using something like Mag Turf Pro), and potassium sulfate to boost K levels.
- Alternatively, what about using calcitic lime along with Sul-Po-Mag (or K & Mag sulfate separately)? Wouldn't these be faster-acting? Or am I better off with the first option? Do I want to be avoiding any additional sulfur?
- Address the B & Mn deficiencies with appropriate compounds (Borax, Mn-sulfate). How often and at what rate considering my EC? Do these need to be addressed right now, or will they improve over time as the other nutrients balance out and the OM hopefully gets broken down? Is there an amendment that would help with both? I was looking at various rock dusts, but they all seem to have higher levels of Al, Cu or Zn, which I don't need.
- What about the surrounding plant beds? I don't want to raise pH too much there as most of the plants are the acid-loving kind. I'm assuming using gypsum and K/Mag sulfate would be better options, along with any organic supplements (eggshells, worm castings).
This sounds like a lot of sulfates. How much will these repeated applications spike sulfur content?
Anything else that I'm missing?
Any help/comments appreciated!
Comments (12)
yardtractor1
7 years agomisterunderhill
7 years agolast modified: 7 years agoRelated Discussions
Soil test results from Logan Labs
Comments (23)1) Technically, after the third mow...which will be a while. That'll be too late for most pre-emergents to catch spring weeds. You could use Tupersan (Siduron) in spring when the forsythia bloom, however. It won't impact the grass, but it only lasts about a month and doesn't have an extremely wide umbrella of what it stops from sprouting. 2) March or April 2016 is great if you want. Done much later, any adjustments will generally have to wait for fall (I really dislike stressing summer lawns). 3) It depends on your locale. That's not completely unreasonable, but I would continue to look around to see if I can find it cheaper. See 4 and 5 below. 4) I paid $14.25 per 50 pounds this year...in eastern Pennsylvania, which is soybean and corn country (as in there's acres of soybean and corn within spitting distance of my house). I also use a grain mill way out in the boondocks, so prices tend to be a little cheaper just because of that. 5) Not necessarily. While corn once a year is a help in terms of a gentle fungus protection (and to diversify the microbes a bit), sticking with Milo isn't a problem if it's cheaper for you. My heavy hitter is soybean meal due to the low cost locally--it beats Milo's price by a mile. If it were the other way around, I'd use Milo instead. Rough app levels are as follows (#/K = pounds per thousand square feet because I'm lazy): Alfalfa: 10-20#/K (the limiter here is the growth hormones, not the nitrogen...this is a weak nitrogen feed, but a good addition in early September to encourage root growth). Corn: 10-65#/K. The lower end helps with fungal protection, the upper end actually provides a feeding for the lawn, and there's no problem using corn at this level--except for the expense, of course. 65#/K delivers about 1 pound of nitrogen. Cottonseed Meal: 15#/K. It's difficult to get up north, but the southerner's equivalent to soybean meal. Milorganite: 20#/K. This is higher than bag rate, but will provide 1#/K of N. This is also rich in iron and contains both fast and slow nitrogen, making it a great pick-me-up for the lawn in addition to feeding it over the long term. Oats, Rice Hulls, Most Other Random Grainy Stuff: 50#/K. Most grains will be around 2% nitrogen (about 14% protein) and are applied at 50#/K to feed at 1#/K of N. They can certainly be applied at lower rates to help organically condition a soil if you wish. Soybean Meal: 15#/K. My personal staple. This provides 1#/K of N....See MoreLogan Lab Soil Test Results // Ref. "Could Red Fescue be my Problem?"
Comments (25)@becky: Good point! I should just boilerplate a disclaimer up top. In some cases, I'm slamming the grass with N. In others, nothing... >>Because the soil was so hard; I thought it may be a heavy clay based soil. So I had the irrigation system programmed to water the lawn every third day applying a half inch of water at a time to eliminate run-off. (So much for what I know!! ) Is the half inch at a time schedule okay? Or do you think the lawn may require more than 1" of water per week? If so; what would you suggest as a watering schedule? I folded all this together. :-) Observation will show you what's required; during cooler weather, like spring and fall, very little watering may be required, or even none at all. I haven't used the sprinklers since September even though rainfall's been a bit low. Half an inch on very sandy soil is generally a good place to start, and figure you may need it twice a week in hot weather. Weekly in pleasant summer weather. I always play it by ear and water when my grass starts to wilt--which also sends the signal to the grass that more root mass might be a good idea. >>Based on the soil test results do you think my soil problem can be corrected On a scale of 1 to 10 with 1 being very bad, and 10 be very good. Where on the scale would you put my soil? All soils can be corrected and yours is certainly no exception to that. Mine started out more than ten times as acidic, with essentially no calcium, modest magnesium, and very low potassium. Not to mention a nearly complete lack of every other resource. These days, it can grow anything I throw into the soil (as long as the plant is compatible with my climate and the sunlight it gets, of course). The problem isn't getting plants to grow, it's getting them to stop taking over! There was a visible battle front between the ageratum and zinnia this year. Overall, I'd give your soil about a 5 at the present instant...it's almost exactly what I'd expect for your locale, without modifications. That can easily be turned up to the 7 to 9 range. 10 is possible but would take years of work....See MoreLogan Lab soil test - need help with results
Comments (7)The soil pH for citrus trees (Oranges) is in the 6.0 to 7.0 range, slightly acidic to neutral and at a soil pH of 6.9 yours is there, but the amount of organic matter in the soil is a bit low at 4.4 percent. Phosphorus (P) is quite high while Potassium (K) is about right as is Calcium and Magnesium. How well does the soil this tree is planted in drain? What does this soil smell like? What kind of life (earthworms, etc.) is in that soil? How well does the soil retain moisture? Perhaps these simple soil tests may help, 1) Soil test for organic material. 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. For example, 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, to a point. Too much organic matter can be bad as well. 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. My experience is that Logan Labs does not offer much help beyond the basic soil test but you might take it to your local office of the University of California Cooperative Extension Service where they may be of more help. kimmq is kimmsr...See MoreLogan Labs soil test results
Comments (9)Refreshing. You're no math or lawn novice. I see you selected to amend potassium to the 4" depth AND accounted for the potassium in the starter. Allow me to throw a curve ball at you. Nearly all fertilizer mixes use potassium chloride as the potassium source. Rather than the 0.5lbs of actual potassium in each lb of SOP, potassium chloride contains 0.6 lbs of potassium per lb of product. A slight adjustment. When making my recommendations, I was leaning more towards a sugar sand with the TEC inflated by clay contamination during sampling. Although application of phosphorous at a rate of 1.25 to 1.3 or so is not detrimental to the grass, the preferred method when applying any amendment is smaller applications over extended time particularly as TEC increases. Your description of the top 4-6" of soil gives me confidence of the accuracy of the 9+ TEC and let's take that into account. Although there is likely some inflation due to the presence of free calcium. Phosphorous: First, I would adjust the the amount for a depth of 4" for consistency as you did for the potassium. 2/3 of 4.75, 3.2, and 4 would be no problem. Second, Let's spread the applications out a bit. Phosphorous is an incredibly slow mover into the soil. Let's give it some increased time, and employ slightly reduced application rates. What is your current nitrogen fertilization regiment? Thirdly, Rather than 18-24-6, a 24-25-X will be more convenient for application purposes. That way you can apply close to 1 lb of N while reducing the P application to 1 lb. per thousand square feet. Potassium: Potassium, although no speed demon, moves down much faster than phosphorous. Generally, I recommend no more than 3lbs of product per application in 3 applications spread out over a season with emphasis on early spring and mid to late fall if well before ground freeze (not a problem for you). I like to separate by 6-8 weeks. Because potassium sulfate and chloride are salts, a reduced rate (1 or 2lbs) should be made during the heat months. Also as chemical N fertilizers are also a salt, try to separate N and K applications by a couple of weeks. This wont create a toxic situation, but the salt presence will increase plant stress and require more attention to watering. Keep in mind that amendments don't got feet and can only move down into the soil on the water train. Amendments should be watered in, followed by weekly water apps. Your atrazine treatment should be no problem. Trace elements: I'm not a fan of playing with these. Unless the turf is actually showing signs of deficiency- malformed plants, leaf streaks etc., there are enough trace elements to satisfy the needs of the grass. It is extremely rare, almost unheard of, that the soil is detrimentally short for the needs of grass. Many of the trace elements cannot successfully be surfaced applied as they almost immediately get tied up upon hitting the soil. Most require foliar application every couple of weeks. Over application can be detrimental, even toxic and very very seldom can anyone see any change for the better. Ending my "vent", (no offense intended to you) most of the trace element amendments can be found on the internet in soluble sulfate form. There used to be/is a site that caters to lawns. Before purchasing, verify that there are instructions for turf application rates. As to your Boron question. To raise Boron by 1 ppm in a 4" depth, 0.43 oz of boron would be applied over 1000 sq feet.. That would require about 3.8 oz of Twenty Mule Team Borax. As you may have guessed, I'm very conservative with these applications. I wouldn't try to make more than a 0.5ppm change in any one season, and I'd divide it into two applications and retest before attempting the next year adjustment. So I wouldn't apply more than one ounce of TMT Borax at a time. Sorry, I have no idea how many tablespoons that is, nor how much Boron would be in 4 tbls. I like to use weight, not volume. We can firm up the P and K rates and timing once you post your current/desired seasonal N regiment....See Moreyardtractor1
7 years agolast modified: 7 years ago
morpheuspa (6B/7A, E. PA)
7 years agomisterunderhill
7 years agoyardtractor1
7 years agomisterunderhill
7 years agolast modified: 7 years agomisterunderhill
7 years agomorpheuspa (6B/7A, E. PA)
7 years agomisterunderhill
7 years ago
morpheuspa (6B/7A, E. PA)