Mel's Mix Lab Analysis Results

For five years I've gardened by the book. It's been MM only. No teas, supplements, additives, fertilizers, emulsions, or extras. It was totally a whim to have my latest batch of MM tested. I was seeking the advice of a plant pathologist (non-soil problem) and decided at the last second as I was heading out the door, that I would get my MM analyzed while I was there. (For those of you in my neck of the woods, our version of the county ag agent is the WSU Extension facility in Puyallup; that's where I went.)

As it turned out, they don't do soil testing, but they did provide a list of certified labs. I sent samples to a local lab in Poulsbo and one to a lab on the east coast. They both had several different test packages to choose from; I chose the ones recommended for home gardens-vegetables where possible .

Lab 1:

pH 6.8
Phosphorus: very high
Potassium: very high
Calcium: very high
Magnesium: very high
Sodium: high
Nitrogen: very high

In summary and suggestions, as written by the QC Manager:

"This sample appears to be more of a compost/vermiculite mix rather than a soil, and the high results back up that observation. The pH is good for vegetable gardens.

The calcium, magnesium, sodium, potassium, phosphorus, and nitrogen are all about 10x higher than the amounts found in a true soil. The ideal thing to do would be to use this as an amendment and not use more than a one part mix to 9 parts regular soil. This will put the nutrient levels in a safe range.

The organic matter is also very high and will release even more nutrients when broken down by microorganisms."


Lab 2:

(They provided results via PDF and the details can be viewed here.

pH 6.8
Phosphorus: very high
Potassium: very high
Calcium: very high
Magnesium: very high
Nitrogen: medium

Micronutrient Levels: within normal range
Misc. metal content: next to none

In summary and suggestions:

"The only adjustment needed is to apply nitrogen 1/4 pound per 100sf. Possible sources are 1lb. of 30-3-3 type fertilizer or 4lbs. of dried blood.

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So there you are: results from two accredited labs that don't agree with each other, nor do they really agree with my assessment of crop growth and harvest.

My summary: I grow everything in MM, and everything is growing as well as it can given my cool weather this year. My corn, a heavy nitrogen feeder, is healthy.

What would you do now that you have numbers, if anything?

My current compost mix is a 6 way, approximately equal amounts:
grass, leaves, mushroom compost, chicken, horse, and cow manures

Boffer, is your mushroom compost bought at the store?



Interesting that they don't have same report. I think your garden does fine, so, I think you've given us a recipe for very good compost. I have chicken, but no cow or horse available. I will see how mine turns out.



I might get mine tested before planting next spring. It's only 10 bucks to test thru Clemson ext. for residents.

Jo

*littlejo, I get mushroom compost by the yard from a local retailer who gets it from the Ostrom Mushroom facility about 20 miles away. It's also available by the bag at better nurseries around here, produced by Whitney Farms.

*trukrebew, I wouldn't doubt that the Teen Wizard has a magic elixir up his sleeve!

So what have I learned? Nothing much. Knowing that my pH is 6.8 or my K is 1171 ppm makes for boring water cooler talk. The numbers are in a usable range just like Mel said they would be. My vegetables have grown just like he said they would. It's still amazing to me sometimes that it really is as simple as using five composts.

As a result of another post ("disappinted in output"), I took a sample of my MM from the garden to the CoOp last week for analysis. The CoOp sent it to the lab, and the lab refused to run it. They said it was "potting soil mix" and that if I wanted an analysis, I'd have to dig deeper and get some "real soil!"

UMass was one of the labs that I used. The standard test. I did not identify my growing medium as MM. It was convenient for me to use the smallest 'If it fits, it ships' boxes from the post office.

It is considered advantageous to utilize a lab close to one's home because they will be familiar with regional soils and appropriate recommendations. I figure it doesn't matter a whit with MM.