Logan Labs Soil Test Help (Zone 5b)

September 5, 2019

Looking for help with my recent Logan Labs soil test. I'm currently in New Hampshire and am in Zone 5b. This is for my backyard where I'm trying to grow a KBG, fescue, rye mix. Looking for recommendations on what to add and would like to stick to organic (non-synthetic) amendments. I've been working at raising the ph the past several years, as I was at 4.8 in 2011, 5.6 in 2014, and added Solu-Cal again this past two springs. I have seen a big drop off in dandelions growing in my lawn and thought that might be a sign I was close on ph. While digging the soil for the tests I was quite surprised at the number of earthworms now present (I owe this to staying with non-synthetics) and there were a bunch of grubs.

Again, any recommendations would be greatly appreciated.

Thank you.

Comments (4)

  • morpheuspa (6B/7A, E. PA)

    Well, this is not a fun soil. And it's not going to be a quick fix, either, because this soil, such as it is, is not going to reward you quickly.

    Amendments are never organic and I can't recommend them that way for measured additions. Plus, in the below I want to overwhelm the soil space with a burst of sulfates to kick out the magnesium ions in solution repeatedly, which I cannot do without a water-soluble molecule...which, by definition, isn't going to be bound to a carbon backbone.

    ME 3.7: Sand. No matter how you slice this, it's sand. Possibly small boulders. :-)

    OM 4%: Good. And combined with the ME, that worries me. It can't go very high because the oxygen penetration is excellent, leading to fast decay of organics. So keep pouring on the organics and live with it.

    Sulfur 20: Fine, with tons of margin to do what I have planned here.

    Phosphorus 600+: Fine, but never use a starter fertilizer or a high-P organic like Milorganite if you can avoid it. You don't really need it.

    Calcium 59%: A little low. I'd very much like to push this up and try to abolish some of the...

    Magnesium 30%: Extremely high, which is kicking your pH up to near-neutral. It's actually high enough to make a sandy soil slightly tight and hard to work. We can get rid of some of this using gypsum, which you can get through most landscape stores. With a low ME, you won't need much. Recommendations below.

    Potassium 2.3%: Low, and you don't have much in the soil reserves. We use potassium sulfate to kick this up and you can order that at the same time you order the gypsum.

    Sodium 2.6%: Hellishly high. Do you have a water softener and water the lawn with softened water? If so, see if you can bypass and use the hard water to water it instead; it's better for the soil. If not, this may be natural--and the other reason I want the gypsum in the amounts I've called for. Sodium is useless to plants (and approaching toxic at these levels to some--grasses are more tolerant, but will wilt much faster when dry). Calcium sulfate (gypsum) will undergo salt metathesis to sodium sulfate and wash out, leaving the calcium (useful) behind and dumping the (highly alkaline and useless) sodium.

    Minor Elements:

    Boron <0.2: Off the charts low and deficient. But if you object to non-organics you're probably going to go bananas at the concept of applying a borate in a carrier (but you can use an organic feeding as a carrier if you want). However, boron is used for cell differentiation, photosynthesis, and a ton of other things. Sandy soils are often short of it. Let me know, there's still space in the schedule to fill it in.

    Most of the rest of the minors look good, although I do wonder where the aluminum came from. That place could almost be a bauxite mine...


    September: Apply 10 pounds per thousand square feet of gypsum (calcium sulfate). I realize you're in NH; gypsum isn't sensitive to ground freeze and isn't a water pollutant.

    October 1 or so, two weeks after the gypsum (it can go at the same time if you like, they don't interact, but I prefer to separate them to give the soil solution time to adjust): Apply 2 pounds per thousand square feet of potassium sulfate.

    April/May (after ground unfreeze): Apply another 10 pounds per thousand of gypsum.

    May 15: Apply 2 pounds per thousand square feet of potassium sulfate.

    September 1: Apply 2 pounds per thousand square feet of potassium sulfate.

    DS_NH thanked morpheuspa (6B/7A, E. PA)
  • DS_NH

    Morpheuspa - Thank you very much for the detailed analysis. Too bad to hear about how "fun" this soil is but that is why we're here. :-)

    I will look around for the sulfate of potash and gypsum and add that to my lawn schedule.

    For general feedings- you mention to keep pouring on organics. I've been using pelletized alfalfa meal as it is reasonably priced and easy for me to get. Are fall applications ok or is this a waste?

    I did some research online about boron and I am interested in adding this to the soil. You mentioned that this can be added to the schedule. Can you let me know and what you mean by adding it to a carrier?

    Again, thank you for taking the time to answer.

  • morpheuspa (6B/7A, E. PA)

    Fall apps of organics are just fine! In fact, I only app organics once in spring--in May--as grasses don't really want a heavy breakfast and hit it hard in fall, in August, September, and October, as grasses really do like a heavy dinner.

    For you in NH, that October application might be a bit touch and go due to being cold and close to ground freeze. For me here near Philly, it's usually just crisp and pleasant with ground freeze due sometime in January. Maybe.

    For that, using urea (still an organic molecule) might be a better option for you to winterize the lawn. 1 pound of fast nitrogen would help out with winter survival, spring green-up, spring performance, and mean it doesn't need feeding until May.

    Now...alfalfa. That can be an issue. Once a year, twice, great, at 10-20 pounds per thousand. More than that? Not so much. It contains triacontanol, a growth stimulant. Which sounds great until you realize that applying too much has the reserve effect and stunts any plant you apply it to. And more than 40 or so pounds per thousand square feet per year will do that. It's one of the unconsidered side effects of organics that nobody tells you.

    I use kelp, which has some of the same issues, but arises from gibberelins, which are less of a problem.

    And alfalfa is only 2% nitrogen. The typical lawn will require 2 to 6 pounds of nitrogen per thousand square feet year for good health (2-4 pounds per K for fescues and rye, 4 to 6 pounds for bluegrasses). While the stricture doesn't apply quite so...strictly...using organics, it's still a good guideline.

    (Pulls up gardening docs) I'm currently at 3.0 pounds N on the lawn, 2.15 from slow organic sources (soybean meal, in my case, as it's a high nitrogen source and cheap for me). 0.85 is from urea nitrogen. The current plan is another 1 pound of nitrogen from soybean meal (15 pounds soy per thousand square feet) and 1 pound nitrogen from urea, for a grand total of 5 pounds of nitrogen for the year.

    Or, pretty average for a bluegrass lawn.

    I'm sure your head's a whirl here.

    You have a really big area to feed, so it's not like you have to do the whole thing, either. Most people feed the area near the house that they use and see well, and let the rest go on a lesser feeding and care schedule. Personally, even I ignore the 2,000 square feet behind the Thuja that I don't see, for the most part. It cuts fifteen percent off my expenses.

    DS_NH thanked morpheuspa (6B/7A, E. PA)
  • morpheuspa (6B/7A, E. PA)

    Now, the boron.

    Boron's usually easy.

    Normally, we use Milorganite as a carrier and 20 Mule Team Borax as the boron source. You can purchase 20 Mules at the grocery store in the laundry section--it's a white box with a blue border these days, unless they just changed it again.

    In a wheelbarrow or the like, dump the Milo. Spraying very, very lightly with water (I use a spray bottle like the kind people use to damp their clothes when they iron) will help the boron stick. Add the recommended amount of 20 Mule Team Borax and stir, spraying occasionally to get the stuff to stick to the Milo. Then apply over the recommended area. So if going for bag rate Milorganite (1 bag per 2,500 square feet), you'd add 12.5 tablespoons of 20 Mule Team Borax.

    It wouldn't hurt to use Milorganite once, so I'd have little objection to you doing so. You wouldn't be applying all that much phosphorus to the phosphorus pit you already have.

    But if you prefer to avoid that--and I certainly support you if you do--I'd suggest using any other organic like an alfalfa or soy or corn meal application and putting that in the wheelbarrow and adding the 20 Mule Team Borax to that. It'll stick the same with a spray of water, although you're likely to find that the stuff does cake up a bit more and needs to be broken apart.

    Don't worry too much about borax dust you lose, it's no huge damage. And yes, 5 tablespoons per thousand square feet isn't much. We're quite literally adjusting your soil levels by 400 parts per billion. This won't do it, but we also don't want to overwhelm any soil level at once. It's the work of years.

    You can apply this any time 2 weeks or more before ground freeze, as long as you do get rainfall, or after the ground unfreezes in spring. It's fairly mobile with rainfall and won't wash off once washed in. Save the remainder for next year, or use it as a color-safe bleach if you like. It really does enhance whites and colors and I use it in my home-made detergent at a 15% rate with the home-made soap to enhance cleansing power.

    DS_NH thanked morpheuspa (6B/7A, E. PA)

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