Pulverized leaves as fertilizer helper...

[studiot]

22 minutes ago, Externet said:

Hi. Yes, shredding (milling) leaves to dust (fine powder as flour) and added to soil is the question.  Nothing involving composting.

 

No, simply adding the dry leaves as fallen in autumn, milled to dust form to soils being tilled to help fertility, not mulching as soil covering, without any rotting or composting,

Two things.

You never told us what you are growing in this soil.

Conventional gardening wisdom is that since to are relying on in place soil microbes to do anything to the dust, you will lower the nitrogen levels of the soil whilst they perform this task for you. In the long run it may improve the soil, but that will take more than a year and by then you will have more leaves.

[Externet]

Thank you.

Yes, plain vegetable gardening as tomatoes, lettuce, onions, garlic, artichokes, melon, cucumber, herbs, a few trees as plum, pear, peach.  Donor leaves are maple, red bud, grass and whatever wind brings from neighbors.  Abundant worms in soil.  Plan is add leaves dust every year if can be beneficial.

[StringJunky]

On 12/11/2021 at 7:06 PM, Externet said:

Thank you.

Yes, plain vegetable gardening as tomatoes, lettuce, onions, garlic, artichokes, melon, cucumber, herbs, a few trees as plum, pear, peach.  Donor leaves are maple, red bud, grass and whatever wind brings from neighbors.  Abundant worms in soil.  Plan is add leaves dust every year if can be beneficial.

There is no significant nutrients in fallen leaves for use by plants. The trees consumed them all before dumping them.  

Edited January 13, 2022 by StringJunky

[zapatos]

Quote

Fall Leaves are a significant source of nutrients such as Carbon, Nitrogen, Phosphorous, and Potassium. As leaves decompose via microbes or worms, these essential nutrients are released into the soil. Leaves also contain various amounts of 12 other nutrients and minerals that likewise feed and improve your garden soil’s fertility.

https://growitbuildit.com/amount-of-nutrients-in-fall-leaves/

[StringJunky]

6 hours ago, zapatos said:

https://growitbuildit.com/amount-of-nutrients-in-fall-leaves/

The numbers are in trace amounts.

[zapatos]

46 minutes ago, StringJunky said:

The numbers are in trace amounts.

Which means what? Not enough to make a difference for other plants? Don't we also only use trace amounts of certain nutrients, which are exactly the amount we need?

[mistermack]

I would be a bit cautious about making dust out of leaves. It would be wise to avoid breathing in any of the dust at least. 

A friend of mine caught legionnairs and very nearly died, from breathing in spray from jet washers. They used a pool of standing water as a reservoir. You never know what you are breathing in, it's best to take precautions. 

[studiot]

9 hours ago, mistermack said:

I would be a bit cautious about making dust out of leaves. It would be wise to avoid breathing in any of the dust at least. 

A friend of mine caught legionnairs and very nearly died, from breathing in spray from jet washers. They used a pool of standing water as a reservoir. You never know what you are breathing in, it's best to take precautions. 

A wise comment. +1

 

Leaves, whether whole or chopped up, contain a high proportion of beneficial organic material.

As such gardeners add the material as a soil conditioner rather than a source of nutrients per se.

I am not sure at what fineness this effect is nullified by 'grinding to dust'. Certainly simply adding carbon particles does not improve the soil.

Edited January 14, 2022 by studiot

[sethoflagos]

On 1/14/2022 at 12:00 AM, StringJunky said:

The numbers are in trace amounts.

If you read the quoted blog link to the end, you'll find:

Quote

Tilling leaves into the garden soil will be a fast way to add organic matter, which can break up compacted clay. But, this will create a nitrogen sink. A nitrogen sink is where the leaves will consume nitrogen from your soil rather than adding nitrogen. A better solution is to make a leaf mulch

... a point that was disputed by some when I raised it earlier. 

Nice have it confirmed!

[zapatos]

1 hour ago, sethoflagos said:

If you read the quoted blog link to the end, you'll find:

... a point that was disputed by some when I raised it earlier. 

Nice have it confirmed!

It was disputed because it was too broad of a statement. Adding too many leaves depletes the soil of nitrogen; adding the correct amount of leaves adds nitrogen to the soil.

Quote

Tip

Since shredded leaves offer nutritional and structural benefits, it is a good idea to shred them and till them into your garden soil.

Nutritional Benefits of Shredded Leaves

Leaves are storehouses for most of the nutrients that plants need to survive. As they break down, the nitrogen, phosphorous, potassium and trace nutrients they contain are released into the soil by the action of microorganisms and fungi that consume the leaf tissues and deposit their own rich waste into the soil, says Nebraska Extension in Stanton County. Other decomposers, such as earthworms and burrowing insects, are attracted to the nutrient-rich soil produced by the rotting leaves and contribute not only their own waste but tunnels they create and that aerate the soil.

...but adding too many leaves in garden soil may a produce nitrogen depletion in the soil as they decompose. 

https://homeguides.sfgate.com/good-add-shredded-leaves-garden-soil-till-103390.html

[StringJunky]

7 hours ago, zapatos said:

It was disputed because it was too broad of a statement. Adding too many leaves depletes the soil of nitrogen; adding the correct amount of leaves adds nitrogen to the soil.

https://homeguides.sfgate.com/good-add-shredded-leaves-garden-soil-till-103390.html

And the 'correct' amount is...?

[zapatos]

5 hours ago, StringJunky said:

And the 'correct' amount is...?

Don't know. Haven't seen that anywhere.

[StringJunky]

28 minutes ago, zapatos said:

Don't know. Haven't seen that anywhere.

I think the answer is "It depends...". If, like I said, there's traces, then they are going to get used used up by the soil microbes to make the nitrates. They won't produce as much or more than they consume.... Law of Conservation and all that.... is it not? Adding leaves is not useles though, as they provide carbon, structure, porosity, moisture retention etc.

Edited January 16, 2022 by StringJunky

[zapatos]

1 hour ago, StringJunky said:

They won't produce as much or more than they consume.... Law of Conservation and all that.... is it not?

I don't know. Nitrogen is fixed in the soil. Is there a net gain, loss, or neutral result due to adding leaves to the soil?

1 hour ago, StringJunky said:

If, like I said, there's traces, then they are going to get used used up

I'm still unsure of the significance of "traces". Doesn't the overall impact depend on how much is used, not on whether it is in an amount considered "traces"? Does "traces" imply it is insignificant for the plants? Or only that it is in very small amounts? Aren't "trace amounts" more than enough under certain circumstances?

[StringJunky]

2 minutes ago, zapatos said:

I don't know. Nitrogen is fixed in the soil. Is there a net gain, loss, or neutral result due to adding leaves to the soil?

I'm still unsure of the significance of "traces". Doesn't the overall impact depend on how much is used, not on whether it is in an amount considered "traces"? Does "traces" imply it is insignificant for the plants? Or only that it is in very small amounts? Aren't "trace amounts" more than enough under certain circumstances?

I'm talking about the macro-nutrients: NPK. If there's little N in the soil and only traces in the dead leaves, then the net N after processing by microbes will be tiny. I'm assuming no initial  N in the soil to keep things clear for discussion.

[StringJunky]

I just learned some soil bacteria and blue-green algae (diazotrophs) can fix nitrogen from air, they are a potential N source.

[Moontanman]

On 1/16/2022 at 2:11 PM, StringJunky said:

I just learned some soil bacteria and blue-green algae (diazotrophs) can fix nitrogen from air, they are a potential N source.

If you set up a kiddie wading pool, maybe one of those 8' ones in a sunny place, add a handful of Azolla, by the end of the summer you'll have a 55 gallon drum full of very nitrogen rich Azolla that can be composted or even plant things directly in compressed Azolla in a pot, I used to use half sawdust and half Azolla for my birds nest ferns, Azolla fixes nitrogen from the atmosphere using photosynthesis. I used to harvest and compost it regularly.  

[zapatos]

1 hour ago, Moontanman said:

If you set up a kiddie wading pool, maybe one of those 8' ones in a sunny place, add a handful of Azolla, by the end of the summer you'll have a 55 gallon drum full of very nitrogen rich Azolla that can be composted or even plant things directly in compressed Azolla in a pot, I used to use half sawdust and half Azolla for my birds nest ferns, Azolla fixes nitrogen from the atmosphere using photosynthesis. I used to harvest and compost it regularly.  

Interesting. Did you get your starter 'handful' from your aquarium?

[mistermack]

Yes, kiddies do give off a lot of nitrates. 😉

[Moontanman]

19 hours ago, zapatos said:

Interesting. Did you get your starter 'handful' from your aquarium?

Yes, up until last year I had a culture I'd kept going for 40+years, I got it from a local lake. Azolla

[Nia]

I have been shredding leaves with a worx leaf shredder for a few yrs now, and they will need to be lightly covered with soil, or covered with something to prevent them from blowing away, or stored by tarping over a pile. Keeping the leaves/area moist will facilitate decomposition, as moisture (and temp) is needed to jump start the life cycle of microbes that break down organic material. When I piled/stored the shreds over winter, and then topped my beds with them, they would be gone in about 2 months, most likely from earth worms that love dead organic plant matter - especially the invasive jumping worm. While yes, there is a nitrogen sink when tilled into the soil, the nitrogen becomes available again as the leaves break down some more - hence the shredding to speed things up, plus unshredded leaves as a mulch can cause a sheet mulching affect (impenetrable layer of water resistant/gas blocking - cause anaerobic situation) - which is why leaves are used as mulch with caution, often to help insulate perennials trees shrubs over winter, and removed when spring arrives. Wood chips (not shreds) does not form a sheet mulch effect, and the fungal growth with moistened can be very quick. All organic mulch will create a thin contact layer of nitrogen sink with the soil it is in contact with, but as the organic mulch breaks down quickest at the contact level, it releases that sunk nitrogen dependent on decomposition time, so leaves will definitely release its original nitrogen plus sunk nitrogen in a few weeks if moisture is present - more so than wood chips. Both are awesome organic method to suppress weeds and slowly (but surely) condition the soil as it breaks down. 

Pine needles does not acidify the soil in fast, large amounts, but rather, slowly breaks down... plus most plants prefer a slightly acidity environment, with blueberries and rhodes and others 'acid-lovers' requiring a low pH medium. I love pine needles, and my source, a fellow about 25 miles away from me who has a giant pine, that I fill my SUV to capacity, sometimes using the attachment trailer too, for the last decade. They are a beautiful mulch, esp for ornamentals, and easy to pull back to plant. And they are wonderful for slopes. They do break down much slower than leaves, and sometimes, slower than wood chips. As I don't have enough needles for my extensively cultivated 1/3 acre, I use the leaf shredder, and wood chips as well.