Fertilizer advice needed

I recently got a soil test on my 36' x 36' vegetable garden. It came back not needing anything - actually on the high side in phosphorous, potassium, calcium, and magnesium. I know it needs some nitrogen, and I'm going to add ammonium sulfate at the recommended rate for that. This is soil that I've been building up for years.

However, I just expanded the garden by 18' on one side, now it's 36' x 54'. I deep-plowed the whole thing yesterday, and I plowed about a half-ton of good compost into the new section. That whole area was fescue pasture for years, but I've kept the new section mowed short for a long time and there wasn't much growing there - just some ground-hugging weeds.

The new area's soil looks good now - dark brown and crumbly, but I know there's practically nothing in the way of nutrients. It's the same as my present garden was originally, and when I started it 15 years ago I got a soil test. I don't remember the details, but it was lacking everything. Per the soil test, they had me till in some lime, 12-12-12 fertilizer, and magnesium, I think. If they had me add anything else, I can't remember it. After doing that, I had great veggies the first year.

I don't want to get still another soil test. Can anyone here give me the amounts of fertilizer and lime to add, per 1000 square feet, assuming this poor old Ozarks soil is lacking everything? If so, I can figure it out from there. Thanks.

You say you added about a half ton of good compost into your new area? Why do you think you need fertilizer? If your concerned about trace elements you can always add a handful of Epsom salts to the mix for the magnesium.

"You say you added about a half ton of good compost into your new area? Why do you think you need fertilizer?"
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Because I made a whole bunch of compost last year and I got a soil test on the compost alone last fall. (you can see why I'm getting tired of paying for soil tests)

The compost I've got is from well-rotted oak sawdust, grass clippings, chopped up oak and hickory leaves, and last year's veggies (mostly corn stalks). Several big bins of it got real hot while working and now it's good-looking crumbly stuff. For nutrients, it tests about - zero, zero, zero, zero.

I called the university extension guy who does the testing about that test last year. He said it's a common misconception that good compost is rich in nutrients like phosphorous, potassium, calcium, and magnesium. It may have a bit of nitrogen and it's great stuff for breaking up clay soil - but it's otherwise neutral. So, I learned something and I'll need to till in fertilizer.

Ozark, that just doesn't make sense to me. I've been doing compost off and on for over 25 years and I've never heard that one. I'm wondering if they messed up your test. Compost is never just neutral......given what goes into it. The ph should be around 7b which is neutral, if that's what you mean. I'll check with my extension agent about this one, since he never mentioned that when we were taking Master Gardener classes. I have not used commercial fertilizers in years, occasionally get some osmocote for my roses, but that's it.

I dunno, I'm just going by what they told me. I know the compost worked good and hot, and it was about a 50/50 mix of browns and greens. It looks, feels, and smells good now - and I'd think it'd be rich in all kinds of nutrients. But, here's the test results on the straight compost:

pH: 5.2 - low
Phosphorus: 5 lbs./acre - very low
Potassium: 66 lbs./acre - very low
Calcium: 1339 lbs./acre - medium
Magnesium: 67 lbs./acre - low
Organic Matter: 81.1%
Neutralizable Acidity: 2.0 meq/100g

By contrast, here's the recent test on my existing vegetable garden soil:

pH: 6.9 - medium
Phosphorus: 276 lbs./acre - very high
Potassium: 552 lbs./acre - very high
Calcium: 4289 lbs./acre - medium
Magnesium: 375 lbs./acre - high
Organic Matter: 18.0%
Neutralizable Acidity: 0.0 meq/100g

Compost is about 1-1-1. During decomposition nitrogen is largely oxidized. What is available is released slowly. Phosphorus is also locked into organic compounds and released slowly. Potassium levels should be good in compost, but it is water soluable.

1-1-1 seems low at first, but keep in mind that compost helps to create the conditions under which nutrients in the soil are made available to plants. Organic matter contains negatively charged particles that hold potassium, calcium and magnesium. Organic nitrogen (not available to plants) is changed to ammonia and nitrates which can be used by plants. Lots of other processes go on too - e.g., nitrogen is fixed from the air into the soil where plants can use it. So, compost and soil work together to create fertility in a process.

I think this is why compost may boost the fertility of the soil once it is applied, over and above the initial 1-1-1 reading.

Also, I know the recommended amount of any nutrient by the soil testers is based on economic factors - they are saying a certain amount of nutrient (no more, no less) has been shown to produce an economically viable amount of crop yield. I'm not sure this approach is always helpful to the home gardener, or, perhaps even to the organic farmer.

I must admit I test my soil anyway though because I'm so curious.

Anyway, I think all is well. I bet if you keep applying compost, your healthy soil will have the right fertility most of the time.

This message was edited Mar 12, 2008 1:56 PM

Intresting, CompostR, I've heard something along the same lines before.

It would be interesting to see if doccat finds any more info. And, it would be nice if a soil scientist were to weigh in.

I went ahead and tilled in lime, magnesium sulfate, and 12-12-12 fertilizer today - all at less than the recommended rates. I think I'm good now. I know the compost has helped the soil texture, and I bet it does help make nutrients available to plants.

I'll be interested, too, to see if we can get some more information on this.

I think the key word is humus and here is a link that explains the difference between it and compost. it also lists the benefits of humus.
http://en.wikipedia.org/wiki/Humus

It is true that compost actually adds very little in terms of fertilizer. If you google such things as "compost NPK" you will find info on this. It generally contains very low (trace) NPK values and some micronutrients.

The best effect of compost, I think, is it's ability to hold any nutrients in the soil for a long time- years!- in a form usable and available to plants for a long period of time. The rotted organic matter forms aggregates, chemical compounds which have the capacity to hold and store any available nutrients for a long time. Non-organic chemical or salty fertilizers simply leach out of soil quickly and pass into our water supply.

Karen

Your need to make a decision. That would be to improve your soil with the organic approach or continue to place stress on your good organic efforts by continued use of poison salts. There is nothing in manufactured chemicals that was ever from the living. They contain no biological elements unless they might arrive in a paper bag. There is no longer any reason for backyard gardeners and smaller truck farmers to not go completely organic in so far as soil additives are concerned.

Let Google educate you about Mycorrhiza. If you were to take out all manufactured fertilizer, add some raw manure one or two falls, run a cover crop and add trace minerals with what you are doing you would have nearly perfect soil building practices in place. Each year would get a little better.

I can see where I believe you have worked so hard to improve your biological soil and then dump in the poison salts that can cripple and kill your living biological content. If you feel you need a little boost in the begining reach out for the better, longer lasting organic fertilizers. I use a little 4 -2- 4 each spring knowing that some of it will still be in the soil and working for me three years later. That is also true of manures, trace minerals and composts. They do not leach. It takes running water of major flow rates to wash them out.

This takes a bit of nerve but you can just forget most advisements given by the present pill bottle soil scientests. Most have not the foggiest idea what good soil building is and have little or no practical experience. Neither do the colleges that educate them. The whole system is grant based. The grants largely come from the chemical producing companies. Their results largely end up being what you might expect them to be. This began a long time ago and continues to this day.
That leaves much to be desired if we are ever going to stop and reverse the soil destruction practices that have been in place for nearly a hundred years.

Acres Magazine......known to be available at Tractor Supply stores is a very good magazine to study for support when anyone wants more information on healthy soil building and the organic process to bigger and better crops.

Amen, docgipe!! Compost, cover crops and all that stuff is good stuff. The healthier your soil the better your plants. They can resist a lot of pests much easier.

Yes, I agree with docgipe. Feed the soil, not the plant. It can be feed with organic mulches like grass clippings, leaves, grain meals, etc, but not just once. It is an ongoing, continual process which keeps bugs and organisms healthy.

You can use small amounts of organic fertilizer to feed the soil which will then feed your plants slowly and not harm the soil or the environment long term. But to do any good you need to keep feeding it organic stuff to keep it alive. No use in feeding once in a lifetime or so with organic materials then undoing the good by applying chemicals and salts to undo what you have accomplished. For organic to work, it has to be a long term commitment.

I try to use only organic practices in my soil but will use chemical crap in containers since there's no real life in that stuff anyway. It's mostly just peat, and runoff is so fast. In my garden soil, which I don't fertilize much, I might use a tiny amount in the planting hole (organic fertilizer only) with spring seedlings, then that's it for the year. Since I started doing the organic thing a few years ago, I am happy with the results I see so far.

And for the occasional really tough stuff, weeds that I can't eliminate I will use Roundup occasionally. This is mostly on the purple deadnettle that is endlessly taking over the neighborhood from one neighbor's yard.

Karen

The organic fertilizer is always listed with low n-p-k numbers because it is slow release.
Unless you overdue the regular salt based fertilizer, you should have no problems with salt buildup. i cheat i use both. even mix them together. I suppose i would be considered a moderate gardener!lol!
i bought 2 pallets of this btn humate with alfalfa for $2 a bag, and a few free busted bags,
because the local nursery bought it at a show and nobody was buying it. I don't know if it is that great of stuff, i need to spread the rest of it! 2 pallets is a lot of anything!lol
http://www.backtonaturecompost.com/naturesblend.html
I guess i am a semi-organic.

"Semi-organic" is how I'd describe myself, too.

I've spent years and many tons of homemade compost building up my existing garden soil, and you can see that's worked well from the soil test I posted above.

But when expanding the garden into a new area, well, this poor old Ozarks soil has nothing in it. Nothing. To make matters even worse, I'm up on the side of a hill, not in a bottom where there might be a little bit of nutrients.

So I've got no problem with starting that new area off with compost and a light dose of chemical fertilizers and lime. That way, I can make garden this year instead of spending a year or two building up the soil. From now on I'll be building that soil with all the compost I can come up with - and I'll be as "organic" as is practical.

lol ozark. but to put things in perspective, just look around and tell me that you live in a barren place, much like a desert with no trees and plants. when i started gardening i figured it would be easy, as i looked around and saw so many things growing and was surprised to hear and read things about how challenging this area is. hmmm. but then they say that everyone thinks that they have the worst soil and conditions. I just plant and occasionally water and fertilize, and act surprised if anything actually does grow.
my grandparents had a farm north of you in morrisville, mo sw of boliver. i'm a little familiar with your rocky, hilly,orange gravel clay soil, but i have to say i remember very well the wonderful wild blackberry cobblers, and fresh tomatoes, and the best tasting, sweetest water i have ever tasted in my life.

Len123 - Yep, I understand what you're saying. I'm from here originally but we spent 30+ years in California, and I guess I got a little spoiled by gardening out there.

We were in a valley at the base of big mountains in CA, and sitting on 3000 feet of sandy loam. It was a semi-desert because of the lack of water, but once you brought water to it that soil would grow anything.

I know Morrisville well, it's on the way to Stockton Lake and I fish a lot. Hey, that's farm country up there - they have some decent soil and they actually grow some crops. Down here in Christian County the road department carries one-quarter sticks of dynamite in their trucks so they can set stop signs and speed limit signs in the ground - and that's the truth.

Different places are different, and I may not think I've got the worst soil in the country - but I bet I'm a contender. lol

Ozark,
I remember when I was at Fort Leonard Wood, Mo. back in '57...you couldn't drive a tent peg in that rocky soil hardly. Then in Fort Polk, La. it was so sandy, a tent peg could hardly hold.