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Organic Nitrogen source.

Posted by pvel 7 (My Page) on
Sat, Apr 11, 09 at 20:45

Hi, I am trying to grow vegetables in my backyard using organic methods. I have been using compost from used coffee grounds/filters and kitchen scraps and shredded paper. I recently got a soil test that says the pH is about 7 and phosphorus and potassium are plentiful but nitrogen is lacking. Question: How I add nitrogen from an organic source?
Thanks. Paul


Follow-Up Postings:

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RE: Organic Nitrogen source.

Pee...can't get any more organic than that


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RE: Organic Nitrogen source.

Nitrogen availability is dependant on soil temperature so if the soil was cooler than plants like to grow in the N test would indicate low amounts available. If your soil is in good condition otherwise with adequate levels of organic matter I'd not be concerned about the N since the soil bacteria will provide ample amounts as that soil warms.


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RE: Organic Nitrogen source.

I would agree that you have to take a soil test as it pertains to N with a grain of salt. Many labs don't even do an N test for this reason.

Having said that, blood meal is a means of supplying N that is often easy to find at garden centers.

Alfalfa and soybean meal are also good sources of N. Some of us use soybean meal as lawn fertilizer (10-20lbs per 1,000 sq ft) so you know it has the N (protein actually) to get the job done.


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RE: Organic Nitrogen source.

My soil test also revealed low nitrogen (very high potassium).
The lab suggested blood meal, someone else suggested alfalfa.

Can anyone tell me how to apply and how much alfalfa, when, etc?
Can I apply it after planting?
I was cautioned that the blood mean might burn my plants, is that a possibility with alfalfa?

Re the soil test - I have dozens of worms in every shovel full of soil, and no problems in having my plants thrive - so it does lead me to wonder - I don't think my soil can be that bad.

thanks,
ellen


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RE: Organic Nitrogen source.

Ellen,

If your plants grow well with no additional N source then you may not need to add anything at all. Adding an N source is mainly if you notice plant growth being slow even though the weather is fine for them or if you notice leaves yellowing starting with the oldest leaves and the soil hasn't been waterlogged recently.

In terms of how much alfalfa to use I couldn't really tell you. With soybean meal my lawn gets it at the rate of 10-20lbs per 1,000 square feet. Broken down to normal garden use it's really just a light dusting of the soil surface and then scratched in (not strictly necessary, but helpful). Under normal, warm growing conditions you can expect the N to be present to the plants in about 2-3 weeks. I base that on the time it takes from application until the time I see the lawn getting darker green.

I would think application rates for alfalfa meal would be the same or a little bit higher.

I terms of burning the plants, that is the result of excessive salts around the roots and that is much more likely with an over application of blood meal than a grain meal.


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RE: Organic Nitrogen source.

The suggested rate of application of alfalfa meal is 10#/1000sf......the same as other grain meals. And you can apply it after planting. Alfalfa starts to decompose very rapidly and decompostion generates heat. This attribute is what makes it so desirable as a compost activator. It is suggested to avoid applying alfalfa directly to planting holes or where it can come into contact with fragile feeder roots, as the heat it generates can burn. Use it as a surface application or lightly scratched into the soil surface.

Nitrogen is the most mobile of the required plant nutrients and its presence is influenced by temperatures, weather, soil moisture, and the activity of soil organisms. That's why most soil tests exclude it or report very conditional, often inaccurate levels - it can change from day to day. If you incorporate adequate levels of organic matter, like compost, composted manure, shredded leaves, grass clippings, etc., either into the soil or as a mulch, the soil organisms should take care of providing an adequate supply.

Or you can supply a more direct source, like the alfalfa or other grain meals, blood meal, bat guano or urine.


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RE: Organic Nitrogen source.

Thanks for that helpful information.

As far as incorporating compst and other organic matter -
for my 7 years of gardening organically I have been of the opinion that "there is no such thing as too much compst", so every year I apply it.
However, I have read, and the people at the soil lab thot, that too much compost can lead to the problem I have of too little nitrogen.
Otoh, the cause might be that I use wood chips in the paths, and my beds not being high enough, the wood chips blow into my beds, so could be the nitrogen is being taken up by the decomposing of the chips.

Anyway, Im not too worried about my soil. As I said, I've got worms, and it has a nice cake-mixture texture, and things grow well. I'm going to use the alfalfa, and I'm not adding any compost this season, and I'm not using wood chips any more.

ellen


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RE: Organic Nitrogen source.

However, I have read, and the people at the soil lab thot, that too much compost can lead to the problem I have of too little nitrogen.

They are correct, but only conditionally so. Nitrogen is a very volatile and slippery nutrient. Most of the N in the raw ingredients going into a compost pile will be lost before the compost is used. If the compost was made using not enough 'green' matter it's final analysis will be too low in N to provide enough for hungry veggies.

If the compost was made with more green stuff, but then left to sit through rain after rain, it may also end up too low in N as it leeches away.

I have access to municipal compost as well as my own compost that I just put into a pile and leave sit until spring. In both cases there isn't enough N for me to not supplement. OTOH if I added a good amount of manure to the pile in the fall there probably would be enough N. Since I am not a huge fan of dealing with manure, I just use soybean meal.


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RE: Organic Nitrogen source.

plant some of the legumes when say 1/2 grown pull them or cut them off and mulch over them. we use green type hay mulches and sometimes some lawn clip, on our gardens it is a continual process as the stuff breaks down quickly, seems to satisfy our plants.

len

Here is a link that might be useful: lens garden page


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RE: Organic Nitrogen source.

Any material that has protein in it is a source of nitrogen. The amino acids that make up protein are made from nitrogen. Any ground up grain, nut, bean, seed, or legume has protein in it. Free protein is available in the form of used coffee grounds. You can get small bags of used coffee grounds for free from Starbucks. Sometimes you can get very large bags from them. If you have a local coffee shop you might be able to make arrangements with them to get coffee that doesn't have trash in it.

Blood meal is an issue only because it is a "hot" material. It decomposes so fast it burns roots. Grains are much slower to decompose and can take a few weeks.

I use alfalfa and corn meal under my plants at the rate of one heaping handful per plant every month. I scatter it under the canopy of the plant. If you have free coffee you can use it like a mulch for a better effect.

Here is a link that might be useful: NPK of Organic Stuff


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RE: Organic Nitrogen source.

I have access to coffee grounds from the local DD. I didn't know this could add Nitrogen. When you say use as a mulch - do you lay it on top of the soil near the plants?
Dig it in?
From what you say, it need not be added to the compost, and let to "cook" before it is used?

thanks,
ellen


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RE:chart of composition

Some questions about that chart of composition -
tea leaves vs tea grounds- Would tea grounds be what is left after you make tea, and tea leaves is before you make the tea?

So can I just apply my used tea bag or gounds to the earth around the plant?

What does 'ash' mean - eg "orange skin (ash)"
Maybe decomposed?

Very interesting, thanks,
ellen


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RE: Organic Nitrogen source.

Mulch is always laid on the soils surface and is never dug in, so mulches will not "rob" any soil of Nitrogen. If that same material is dug into the soil it is now a soil amendment and not a mulch. With your coffee grounds, or tea bags, you have a choice of either simply plunking them down on the soil or working them into the soil. Given the N level of either there would be less chance of N depletion using these as soil amendments, and even less if used as a mulch.


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RE: Organic Nitrogen source.

Nitrogen depletion as a result of using compost is generally limited to unfinished compost that is heavy in browns or carbon sources. Otherwise, finished compost is pretty stable in the amount of nitrogen it supplies dependent on source materials.

I too don't think you can add too much compost. It has benefits far and above what it offers nutritionally. But harvestable vegetable crops in particular can have higher nutrient demands than just compost alone can supply. So supplementing compost with an additional source of nutrients is often advised. And necessary :-)

I've attached a link on growing veggies in New England that seems particularly appropriate, as it discusses both compost as a nutrient source and the nutrient "pull" of various vegetable crops. And there is an obvious gap between the two.

Here is a link that might be useful: Veggies in New England


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RE: Organic Nitrogen source.

pvel: my advice won't do you a bit of good this year, but the answer is to grow legumes in rotation -- and this includes over-winter cover crops. So, thinking ahead, you will need to 1. plan your crop rotation, 2. plant one section to peas and beans this season, and 3. plant one or more sections to clover or hairy vetch this fall. Regards, Peter.


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RE: Organic Nitrogen source.

Ash is what is left after incineration. Usually it is a source of potassium (potash).


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RE: Organic Nitrogen source.

If organic matter (straw, compost, manure, plant stubble, fish emulsion, etc.) is added to the soil, it will be eaten by organisms living in the soil. All living things need nitrogen to build proteins. If the organic matter is rich in nitrogen, the soil organisms use that nitrogen to live. Eventually, they release excess nitrogen into the soil as ammonia.

Organic matter and available nitrogen are closely related, so if you add organic matter you need to consider how it will affect the nitrogen supply in the soil.

If low-nitrogen organic matter (e.g., straw or sawdust) is being broken down in the soil, however, the bacteria and fungi have to use available soil nitrogen to build their proteins, so there won't be much left for plants. If you want to provide extra nitrogen for the breakdown of course organic matter, add 3-4 lb of actual N per cubic yard of material such as dried leaves, sawdust, or shredded bark.

Regardless of the organic matter source, when it is all digested, the bacteria and other organisms that were feasting on it die. The dead nitrogen-rich bodies then are broken down by other organisms that release the excess nitrogen for eventual use by plants and microorganisms.


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RE: Organic Nitrogen source.

What about temperature and time of year? I live in Silicon Valley and we've had several days of frost. After completing an OTC soil test, I saw practically no nitrogen or phosphorous. Reading this thread, I see that cooler temps can skew results.

How warm is warm enough to get decent results and how cold is too cold to add topicals such as fish emulsion, alfalfa, and blood meal?


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RE: Organic Nitrogen source.

Gardengal48: I have read much of what you have written over the last year or so and find you to be pretty well informed; however this statement coming from you blows my mind, "Nitrogen is the most mobile of the required plant nutrients and its presence is influenced by temperatures, weather, soil moisture, and the activity of soil organisms. That's why most soil tests exclude it or report very conditional, often inaccurate levels - it can change from day to day."

Yep, those things certainly influence plant available N in the soil but if one is cognizant of N's unique properties in the soil it makes perfect sense to sample for it. Labs don't report it for the reasons you mention, you've got to be kidding me.

Humbly,
Michael


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