Making your own soil.

[TorturedSoul]

I've been wondering:

How would you tell the NPK (and everything else) of your compost? I mean, wouldn't everyone's be different depending on what they put in it and what ratios?

[obxgardener]

Originally Posted by TorturedSoul

I've been wondering:

How would you tell the NPK (and everything else) of your compost? I mean, wouldn't everyone's be different depending on what they put in it and what ratios?

Yes - green material would raise the N, while I believe the brown raises the P & K... but to know the exact ratios, you'd have to send it off to be tested - or I think there are at home soil test kits.

There are books on composting that suggest adding rock dust for some minor nutrients.

From what I've seen, the only problem I've had is an abundance of nitrogen leading to growth that exceeded the calcium supply - causing blossom end rot on tomatoes - but it's not been a problem since I've added bone meal. If I had something to crush oyster shells with, I'd do that too... I guess I could just use a hammer and a bag.

[obxgardener]

I've been doing some research on Tortured Soul's question, and there is not much out there that goes past the Nitrogen : Carbon ratio, or what I've simplified to Green : Brown ratio.

It seems that the relative amounts of nutrients depends on how much bacteria is in the soil, converting the organic nitrogen to a form that can be taken up by plants. So, there might be a ton of N, but if the pile has not composted it long enough, or if there is not enough Brown (carbon) to power the process, there will be a deficiency in available N.

So, nutrient content really comes down to keeping the brown / green ratio correct, and allowing enough air & water to infiltrate the pile to keep the bacteria converting the materials to a plant usable form.

Of course, you can also use worms to convert the organic N to worm casings, which have about .5 N available to the plant.

Anaerobic (airless) bacteria will do it too, but it takes longer, and can produce smells.

[PotPie]

Originally Posted by obxgardener

From what I've seen, the only problem I've had is an abundance of nitrogen leading to growth that exceeded the calcium supply - causing blossom end rot on tomatoes - but it's not been a problem since I've added bone meal. If I had something to crush oyster shells with, I'd do that too... I guess I could just use a hammer and a bag.

When I lived on the east coast I used to buy 50# bags of crushed oyster shells at Southern States feed stores. I used them to supplement chicken feed to make sure the girls laid eggs with nice firm shells. I had blossom end rot on my tomatoes too until I found out that it was caused by a calcium def. I scratched in a handful of shells around each plant and watered thoroughly. No more blossom end rot. I know 50# is too much for you but some places will have it in bulk and sell you 5 or 10lbs. A 50# bag is cheap, like 6 0r 7 bucks as I recall. Some places will give you a big bag for a buck or two if it broke open and they can't sell it otherwise.

[obxgardener]

Originally Posted by PotPie

When I lived on the east coast I used to buy 50# bags of crushed oyster shells at Southern States feed stores. I used them to supplement chicken feed to make sure the girls laid eggs with nice firm shells. I had blossom end rot on my tomatoes too until I found out that it was caused by a calcium def. I scratched in a handful of shells around each plant and watered thoroughly. No more blossom end rot. I know 50# is too much for you but some places will have it in bulk and sell you 5 or 10lbs. A 50# bag is cheap, like 6 0r 7 bucks as I recall. Some places will give you a big bag for a buck or two if it broke open and they can't sell it otherwise.

Oh, don't worry, I eat them for their shells... although this is the last month with an "R" in it.

[Ms.Fox]

Great info obxgardener! + reps!

[obxgardener]

Thank You Ms. Fox!

[obxgardener]

Apparently, most states have free soil testing if you don't mind waiting a while... try googling the agricultural extension office for whatever state you are in.

[Frog]

Texas pops me 7$ a sample.

No free ride here,
unless you wait for a free workshop, maybe once a year.

[obxgardener]

Originally Posted by *********

Texas pops me 7$ a sample.

No free ride here,
unless you wait for a free workshop, maybe once a year.

That's Texas for ya... do you find it worth sending in?

[TorturedSoul]

I got a wild hair and googled Texas free soil test... And although the first few were older, there was one on the first page of results from this month of a newspaper article about several locations doing free soil tests "this Saturday" around the area of Battle Creek. Something to do with helping area residents comply with the no-phosphorous fertilizer ordinance that went into affect March 15.

Unfortunately, the article was published on the 16th, so "this Saturday" was actually LAST Saturday, but it does show that you can from time to time find free soil tests more often than once a year. Google is your friend (sometimes).

[l8tnightskunk]

texas yes!

[Frog]

Originally Posted by obxgardener

That's Texas for ya... do you find it worth sending in?

Nah, I just watch the ph.
Mine seems to be around 6.7-.8 in all my beds.
So I've started just growing what veggies that like that ph.
And experiment with a few others.
I have found seed will take better to an off ph than starter plants do.
Your germination rates are For sure lower.

I have seen a test kit for $200+, suitcase looking thing.
not sure how many samples you can run before re-filling.
I'll see if I can re-google it

The guide:
Soil Quality Test Kit Guide

The Soil Quality Test Kit Guide describes procedures for 12 on-farm tests, an interpretive section for each test, data recording sheets, and a section on how to build your own kit. The NRCS does not build or sell soil quality test kits. Kits are being sold by Gempler's and by Murray FFA in Murray, Iowa.

(Disclaimer: Trade names are used solely to provide specific information. Mention of a trade name does not constitute a guarantee of the product by the U.S. Department of Agriculture nor does it imply endorsement by the Department or the Natural Resources Conservation Service over comparable products that are not named.)

Found one for $600+:
Soil Test Kit, Soil Test Kits, Pest Management - GEMPLER'S
"Professional Soil Quality Test Kit

Diagnose profit robbing soil health problems without lab fees

Soil test kit includes all the supplies you need for these tests:

• Soil Respiration • Infiltration • Bulk Density
• Salinity (EC) • pH • Soil Nitrate
• Aggregate Stability • Earthworms • Compaction
• Soil Structure • Soil Texture • Water Quality

Modeled after a USDA-developed kit, this soil test kit includes the tools you need for a thorough assessment of you soil's ability to perform its critical functions: supporting plant and animal productivity, contributing to clean surface and ground water supplies, and enhancing human health, habitation and recreation. Save time and money by testing your soil quality without having to send samples to the lab. Kit can complete 25 soil nitrate tests, 10 soil respiration tests, and an unlimited number of other critical tests. Kit includes an easy-to-follow instruction booklet written by USDA scientists. Consistently monitoring soil quality is an important part of any IPM program."

[obxgardener]

Just thought I'd bump this thread with a shot of a seed that started in last year's compost pile, now a bed... it's pretty early in the season for a zucchini to be this big. It's a mystery why several seeds have started that I either planted years ago, or are from last year's veggies that got too big and went in the compost. Either way, I just put a bunch of tomato plants in, and I have to train the zucchini to keep it from smothering everything. I've only seen a plant grow this fast in mid or late summer.

[obxgardener]

I've been testing a composter made from a black trash can, and it works pretty well.

Here's what to do for an easy first composter -

1) Get a plastic trash can with a tight fitting lid. ($10 bucks at most hardware stores compared to $100 or more for a plastic composter)

2) Using a skill saw (carefully) pull back the blade guard and slowly make a vertical cut into the trash can in the lower third, stopping when it's at least 4 inches long. Repeat around the bottom, then middle, and top, with at least ten cuts at each level. You basically want to end up with 1/4" x 4" vents all around.

3) If you have a mower with a bag, fill up the can with a mix of grass, twigs, leaves... just about anything organic that the mover will chop up. You want about a 1 to 1 ratio of green grass to brown stuff. If you don't have a mower, just keep the size of what you put in kinda small... big twigs will take forever to compost if they are not chopped into tiny pieces.

4) Add kitchen wastes to really get the pile going... chop them up as small as you can, then mix it in and water the compost until it's about as wet as a squeezed out sponge (too wet will hinder the process as much as too dry).

5) Put the lid on a leave it for a few days... then mix it with a pitchfork or cultivator to keep the rotted material mixed with the fresh grass and leaves. You could also just dump the can into another can to mix the material... the key is to keep the process going by having the brown, green, and rotted parts all mixed together and aerated.

6) You will know it's going well if the mix smells like a mulch pile when you lift off the lid, and you will feel the heat of the composting, and even see steam from the pile when you turn it. Keep grass or something on top of the kitchen wastes to keep the flies away.

7) If the compost does not heat up, add more green material and kitchen wastes, and mix well. If the compost stinks like manure, mix in dry leaves, dry grass clippings, paper, pine needles... anything brown.

8) In about two weeks, you will notice the volume reducing, and the mix turning black and crumbly. After about 4 weeks, it may be ready to mix in the ground for an outdoor garden.

9) To "finish" the mix for more sensitive uses, put in a black trash can with no holes and a tight fitting lid and leave it out in the sun... the heat and moisture should sprout any weed seeds still in the mix... check on it occasionally, and use it when seeds stop sprouting and it pretty much looks like dirt.

The great thing about this type of compost is that it's nearly impossible to "burn" your plants as can happen with manure based composts. You can pretty much grow plants right in it, or cut it with some perlite and peat moss if you like to add your own nutrients.