If I add 1000 pounds of compost, how much NPK am I adding?

http://www.gardenmyths.com/compost-fertilizer-numbers/

Sounds like 0.03%, for available nitrogen. So in 1000 lbs of compost, you're getting about a handful of available N.

If you want unavailable nitrogen, why bother with compost? Just bury a log.

Sorta depends on the starting material doesn't it? Not everyone religiously follows the carbon to nitrogen ratios recommended by Rodales, you know. Also a guy who loads his pile with a lot of chicken manure is more likely to have a more Nitrogen rich end product than your average kitchen composter.

I expect the vegetation in my naturally Potassium rich area to provide a P rich compost compared to some other places.

Don't expect to find deficiencies of trace materials in any area where significant compost has been added. Expect good things for soil structure.

So basically, you take care of everything but N and you have a good head start on pH assuming that you have to do anything at all about pH. That and a pickup truck I have to put to good use is enough to get me to compost

I do love a good dirtfight. Thanks yall. I was otherwise bored at work today.

Let me add to that. 0.03% of compost is available nitrogen. As in, available for use by plants NOW. The total nitrogen in compost is of order 1%. Yes, it is a bit higher in poultry manure compost. The process of "mineralization" is the conversion of organic nitrogen (in proteins and the like), which is that 0.97% non-plant-usable nitrogen, into inorganic nitrates and ammonium ions, which is a form of nitrogen that is usable by plants. The ROM mineralization conversion rate is 10%/year. So in the course of a year, you'd end up getting 10%x1%=0.1% of the compost in the form of plant-usable nitrogen. That would be 10 lbs of plant usable nitrogen in a year.

Simple lawn fertilizer is about 25% plant-usable nitrogen. So a 40 pound bag of that stuff would provide as much nitrogen fertilization in a year as 1000 lbs of compost. Take your pick. You want to call compost a nitrogen fertilizer?

So your compost is potassium rich because you live in a potassium rich area? Duh. What you're taking out of the soil you're just putting back in. If your soil is potassium-rich, you sure don't need a potassium fertilizer. Don't expect to find deficiencies of trace materials just about anywhere, whether or not compost has been added. If it's your own compost you're using, a deficiency in your soil will be reflected as deficiency in your compost.

But to many, compost is a religion. It's not about science. It's about gospel. I get that. It's so wonderful, it simply must be a fertilizer! Sometimes I think it fertilizes the imagination of gardeners more than it fertilizes plants.

Dirtfight? I like that. At least it's not a manure-fight.

"If you want unavailable nitrogen, why bother with compost? Just bury a log."

I guess that pretty well negates any kind of intelligent discussion on the topic.

As to intelligent discussion on this topic, let's not get our hopes up.

Aww yall are forgetting this 5 foot rod I can sink into my garden but not my yard. We use a lot more inputs in the garden, but just have let a lawn service go that was runnin spray hoses every month. Why is the garden soft to china and the lawn a 6 inch and stop for that rod?

See what I mean?

He's not grasping the humour tricky.

Yep, I grasped it, but I didn't connect it with intelligence.

Well Dan, aren't we agreeing then?

If your plants still aren't thriving with a significant amendment of properly made compost to the soil the culprit is almost certainly going to be N?

Dan I get the feeling you might like to stop by a reddit called r/trees. They do a awful lot of nutrient only growth but you might also say they have a particular focus. Might help you out though. You might see things a little differently after that trip.

"If your plants still aren't thriving with a significant amendment of
properly made compost to the soil the culprit is almost certainly going
to be N?"

You can have serious deficiencies in a number of soil nutrients. If you're using properly made compost made from plants grown in your own soil, that compost won't correct these deficiencies. Period. C'mon. This isn't that hard.

Compost doesn't make nutrients out of thin air, though I guess some here believe that it does.

I agree with you. The heat here works the micro nutrients pretty hard. Its like revving a motor up with heat energy. Fuel gets consumed. The old women call for epsom salts and molasses, but sugar and sulfur make things tick underground because they get consumed or washed in our considerable rains. However some components that were sucked out of the ground will be in compost, but its the myco and bacterial life that is the real kicker. Compost Tea and similiar ideas stem from the idea. Gotta feed the bugs in realtime.

Show of hands....how many people make compost solely from plants grown in your own soil?

I do not.

Oooh. Compost tea. Don't get me started. Myths come in bunches, I guess.

Look, I have a friend who is in an area that has been established to be selenium deficient. That's pretty unusual for a micro-nutrient, but that's what it is. His compost will not supply selenium to his plants. Has nothing to do with stuff being "consumed". It's just not there. It won't get sucked out of the ground and, as a result, won't get put back in. BTW, heat has absolutely nothing to do with micronutrients.

"Show of hands....how many people make compost solely from plants grown in your own soil?"

I sure do. I don't trust the stuff I get in the stores. Herbicidal contaminated compost is pretty rampant. I got some from a local big box store and had big problems in that bed. That compost has now disappeared from that big box store this year. Wonder why. The kitchen waste that goes into my compost is a tiny tiny fraction of the whole. Most of it is leaves and yard trimmings. My leaves and yard trimmings.

The idea that someone elses compost has the nutrients that my soil is deficient in is pretty much just wishful thinking.

"I sure do. "

So no produce or plant residuals originating from outside your property goes into the compost. Interesting. I couldn't imagine not using the banana peels, orange rinds, coffee grounds, etc etc in my compost.

You didn't read what I said.

"The kitchen waste that goes into my compost is a tiny tiny fraction of
the whole. Most of it is leaves and yard trimmings. My leaves and yard
trimmings."

There. That help? No, I don't make it SOLELY from plants grown in my own soil, but that's the vast majority of it. If I needed selenium, I'd be up the creek. Not sure where this question is going. Got a point to make? You know, intelligent discussion, and all that.

hahaha...Au contraire my friend, I did read what you wrote, very carefully. You even quoted my question and replied "I sure do". Your statement about kitchen waste, in no way states that said waste is not from your own property. I'd also be curious to know how you keep other peoples leaves from blowing onto your property but I can't be bothered. Have a nice day Dan.

C'mon, Lloyd. You were the one bemoaning the lack of intelligent discussion. My kitchen waste is largely not from my own property. Mostly from the supermarket. So what? My leaves are from my own property and houses adjacent, whose soil properties are identical to mine. So my compost almost entirely represents the composition of my own soil. So what?

As I say, got a point to make? Guess not. I can be bothered asking that repeatedly.

I wanted to ask this question long time ago and it seems this thread is a good place for it. When I drive amongst very thick forests along our highways, I always think where these huge trees take nutrients to grow so mighty? The soil is rocky clay and rocks. Let say this forest has fertile soil about 2” maximum. How could this be enough to grow big trees too close to each other, too high,and have too thick trunks?

If they don’t absorb nutrients from air, where they take it from? And if trees are able to absorb it from air by leaves/needles, why can’t compost absorb it by bacteria, mycelia, molds, etc.?

Clay has plenty of nutrients. No way the soil is 2" deep. The cracks between rocks have plenty of soil, and the roots head for those cracks. That soil percolates down from the surface with water. The roots can "see" a lot deeper than you can. If it were solid rock all the way down, there wouldn't be any trees. Period. Carbon dioxide and some oxygen is absorbed from the air. That's all. Everything else comes from the soil.

Have you not seen a large tree that was uprooted? The roots aren't two inches deep. They go down many many feet, and the ones that were broken off go even deeper.

Compost doesn't "absorb" nutrients. It IS nutritive material, though those nutrients are released on a long timescale. Compost is fertilizer in the same way that rocks are sand. One is eventually broken down into the other. (Takes longer for rocks though.)

I meant to say 2" fertile soil under leave mold. I believe that here, in SE, forest drinks from air mostly, than from ground. this bricky clay soil has not too much moist to let the tree to grow so mighty.

So , if trees are able to drink by leaves, they drink not just pure H2O from air, but also all other elements, which are able to dissolve in water.

Similar things should probably happen with compost pile when fungi drink dew or rain, ...

Btw, I wonder how pea, or clover are able to absorb N from air and collect it in their roots?

You're almost there avgusta. You've got all the elements and you've almost got them connected.

From my own experience in clearing 1 acre of thick wild forest on my property, I could say that local trees, pine, different type of oaks, beech, cotton, tulip, sweet gum have no more than 2 ' deep roots, they spread their roots horizontally as long as they could. They prefer to be on surface than under.

When I ride passing forest harvesting sites, I see many uprooted trees and stumps. Their roots also not deeper 3' maximum.

Drinks from air? Drink other elements dissolved in water they drink from air? Nope. The water in the air (which they don't drink from their leaves) is distilled water. Nothing in it, except some dissolved atmospheric gases. Bacteria working with legume roots take nitrogen from the air (largely that dissolved in rain water) and convert it into ammonia, which can get further mineralized by soil bacteria into nitrates that plants can use. You might want to read up on nitrogen fixation by legumes. Pretty fascinating. Here's a nice reference from our ag school.

http://overton.tamu.edu/faculty-staff/gerald-wayne-evers/cool-season-legumes/nitrogen-fixation/#.WMdCFBB_zWk

The "fertile soil", as I said, is in the spaces between the rocks, deep down under. The fertility of that soil is guaranteed by leaching of nutrients at the surface.

When you see an uprooted tree, you're looking at broken off roots. Most
of the root system of the tree is left in the ground. Below a few feet,
the roots are fine enough to easily break when stressed. That being the case, yes, many trees have root systems that spread laterally.

As Lloyd says, you've got the right words. Just have to put them together properly.

I disagree with you. Dr Elaine Ingham teaches that your misuse of the word fertility would be better described as an understanding of the biodromes ability to digest those deep materials and bring them forth, with respect to the heat and oxygen powering the event from the top few inches of soil where the intercession of primary nutrients fuel the event.

That's true, that deep fertility is partly in situ, in that some soil digestion is happening at depth, but a lot of the nutrients are due to leachates from the surface, where aerobic digestion is taking place. She's correct that soil fertility is a matter of getting the soil biology correct, but that happens on a long timescale. Not on the timescale of a single growing season. That is, you can't innoculate the soil with all manner of beneficial bacteria in biological equilibrium and BOOM, you have fertile soil.

Yet she injects deeply with the intent to jumpstart that exact process, and drumroll please, she is bioreacting sourced materials to target specific nutrient flow.

I did not say tea. I am very proud of that.

I don't understand your words. You speaking English?

Well, You make me think about filing the complaint to the public educational system for teaching us wrong things at school.:)) Previously, it was known that leaves have stomata for exchanging gases and water vapor both ways. That could mean a plant gets inside everything what is around in air. How can epithyte survive without roots (and access to soil) if leaves cannot drink from air?

Epiphytes have roots - that's how they anchor themselves to their support plant. And those roots also do the same thing inground roots do - they access moisture and nutrients from the surroundings as well as from the air and rainfall.

There is a limit on what can be absorbed through a plants leaves or other foliage. Primarily the stomata exist for gas exchange. Water vapor is also released as part of photosynthetic process but far more moisture escapes or is released through the leaves than is absorbed. It is primarily the root system that is responsible for taking up the moisture and nutrients plants need to survive.

Trees grow big because they are able to produce very expansive, far reaching root systems. They take in virtually all that is needed in the way of moisture and nutrients through these roots - not via leaves or needles or any other above ground parts. These wide spreading root systems are able to access moisture and nutrients at a considerable distance away from th base of the tree, sometimes hundreds of feet. And there is a lot more nutrient availability in that 'poor, rocky soil' than you might expect. Not to mention all that natural 'compost' that occurs with the accumulation of fallen vegetation, etc. on the forest floor.

btw, it might be helpful to know that any kind of tree - even tap rooted trees - will have the majority of its root system located within the top 24" of the soil profile and much of that just below the soil surface. This is where the bulk of the soil moisture and nutrients are located so this is where the feeder roots are located. Also the strongest mycorrhizal association. The spread of the root system has a rough association with the height of the tree, not the canopy spread, and will typically extend 2-3 times the height and often further, depending on how easy the necessary nutrients and moisture are to access.

How do trees grow so big with minimal soil? Because most of their mass is not minerals. Wood is roughly 50% water (depending on species), for starters. Of the half that is not water, almost all of it is carbohydrates of one kind or another. The general formula being (CH20)x essentially made up of carbon dioxide and water. This is evident when you burn a piece of wood and get 1% back in ashes. So it doesn't take much mineral matter to make a tree. When leaves, limbs or the whole tree fall back to the ground, of course, it's recycled.

I'm a big fan of trees. They're just amazing, cool, beautiful, and they give us so many products and services. Heck, Ima go hug one now. :-P

Everything what you say I understand. But , how do all these monster trees (or their roots) do not choke each other by having only about 1yd distance between trunks?

Nothing grow well near "forest" trees, I mean veggies or flowers or grass or fruit trees, all them do not do well regardless of regular watering and feeding. Trees just steal everything immediately .

Compare to size of any tree, roses or veggies have even less minerals, but we cannot get good bloom or harvest or even normal grow without adding religiously compost and fertilizers. And we are planting garden plants in the best soil possible to find , and which was at least 1 foot soft. It 's just a puzzle .

Leaves will "drink" from air if it is about 90-100% of moisture, that we have on east coast almost year around.

Yes, it's a puzzle. Amazing how nature do dat. :-D

A big tree can suck up tens to even a hundred gallons of water per day. I have tree root problems in my garden and even if I cut the shallow ones, it seems the deeper ones a couple feet down and more are sucking moisture out of the garden beds. If it's hot and dry in the summer I just can't seem to water them enough. But I can't see cutting down all my trees either.

This little exert sums it up pretty tidily: "The leaves of a plant are covered in cuticles and stomata. The cuticles are a waxlike substance that waterproof the leaves, making it difficult for them to absorb water. The stomata are small pores that release water vapor and oxygen and, in turn, take in carbon dioxide. However, the concentration of the water vapor in the leaf drastically exceeds the concentration outside of the leaf (aka the humidity outside). This causes the water vapor to be 'sucked' out of the pores of the stomata (sing. stoma) and into the air, a process known as transpiration. As a result, water absorbed from the roots is pulled up the xylems (the plant's tissue that transports water) and distributed to the stem and leaves of the plant for photosynthesis to be achieved. To summarize, plants generally do not take in water through their leaves, but rely on their root system for this. There are some advantages to watering a plant's foliage, such as preventing it from becoming too dry (and potentially becoming susceptible to fires), but also cleansing the plant of accumulated dust." (emphasis mine)

There will be some absorption through foliage but rarely enough to keep a plant - and especially trees - fully hydrated. The bulk of the moisture and nutrients a plant needs to thrive is accessed by the roots.

btw, this is all basic botany.

Thank you Gardengal48, I didn't argue with that. I just trying to say this is not the only way of how plants survive. There are different conditions and different species and different adaptation technics .

http://www.saps.org.uk/secondary/news-and-research/1267-how-plants-can-suck-water-from-the-sky

"But recent research has shown that our traditional understanding of the movement of water through plants is incomplete. Under certain specialised conditions, some plants have evolved the ability to absorb water through their leaves, move it down the xylem, and them release it into the soil. The plants are actually watering their own roots - and their own seedlings. This off-beat mechanism for water uptake works well enough that these plants can continue to photosynthesise and grow, even when the soil they are growing in are dry.

The trees the researchers studied - Drimys brasiliensis - grow in the cloud forests of Brazil, where the trees are almost constantly covered in fog. The atmosphere around the leaves has a higher water potential than the leaves themselves, allowing foliar water uptake. The exact pathway for water entry is still under discussion: this particular species has a hydrophilic cuticle that could facilitate water entry, as well as hydrophilic tissues within the leaf that could provide water storage.

At least 70 species, across seven different ecosystems, have been identified as using this 'back-to-front' water transport mechanism, pulling water out of the sky and down to the rhizosphere.

These new findings have important implications for our existing models of the climate and our ecosystems, which often consider soil water as the only source of water for plants.

It's another example of how plants are constantly over-turning our expectations. "

I'm still going to spray down a wilted plant when I see one, but now I see that (unless I'm in a cloud forest) all I'm probably doing is increasing the humidity on the leaf surface which will MAYBE cut down on the loss of water OUT of the leaves until the roots can catch up from the watering. Plus, it makes me feel better. Poor wilty plant.

Another Question pops up. Why is it recommended sometime to feed a plant on leaves if it cannot absorb anything but CO2 through leaves? And why is this feeding applying after dissolving in water?

Not just in a cloud forest. There is an amazing plant Welwitschia mirabilis.

https://www.plantzafrica.com/plantwxyz/welwitschia.htm

"It grows in isolated communities in the Namib Desert, in a narrow strip, about 1 000 km along up the coast from the Kuiseb River in central Namibia to Mossamedes in southern Angola.

Welwitschia is ecologically highly specialized, and is adapted to grow under arid conditions receiving regular fog. This regular, dense fog is formed when the cold north-flowing Benguela Current meets the hot air coming off the Namib Desert. The fog develops during the night and usually subsides by about 10 a.m The leaves are broad and large and droop downwards. This is an ideal way for it to water its own roots from water collected by condensation. It also has numerous stomata on both leaf surfaces and fog-water is taken up directly through these stomata. The fog has been estimated to contribute 50 mm in annual rainfall, but in spite of the fog, the plants are still dependent on additional sources. Rainfall in this area is erratic and extremely low, only 10 - 100 mm during the summer months. In some years, no rain falls at all."

Obviously plants are able to take up through their leaves otherwise products like glyphosate would not be effective. Frankly I don't care how, why or what. Knowing that they obviously do is sufficient for me. Having said that, it is also obvious that the vast majority of water/nutrients is taken up through the roots of the vast majority of plants in my world. Good enough for me.

My point of asking all these "how" questions is to question the statement that compost cannot absorb elements from air by mold, or fungi, or something else that is growing in it while compost is cooking. If other different plants can do that, why "composting plants" could not? There is enough N in air, and other gazes , why not use it?

I'm not sure what you mean by "cooking", but at least indirectly, compost can play a part in the nitrogen cycle. I'd recommend you not get strung out on what some people pontificate around here (including me) and just go with good sense. Sometimes it is enough to know that you are correct and not spend a lot of brain energy trying to convince those that shall remain forever unconvinced.

" If other different plants can do that, why "composting plants" could not?"

You have just answered your own question!! Live plants photosynthesize and transpirate - "composting plants" do not. The absorption of any material via plant foliage is undertaken during the biological and metabolic activity of a living plant. The ability to do this is simply no longer present in a plant that is no longer alive.

btw, very few ever recommend fertilizing your typical leafy plant with only foliar applications. The reasons why?..........it is simply just not efficient.

I thought molds, fungi, mushrooms are living "plants", or at least they are something that grow which means they are alive for me.

"PUBLIC RELEASE: 30-MAR-2015

Mist-collecting plants may bioinspire technology to help alleviate global water shortages

Mimicking a unique water collection-and-release feature found in plants with tiny conical 'hairs' or microfibers on the surface of their leaves may enable a technology capable of pulling fresh water from the air

AMERICAN INSTITUTE OF PHYSICS

WASHINGTON D.C., March 30, 2015 - Plants living in arid, mountainous and humid regions of the planet often rely on their leaves to obtain the moisture they need for survival by pulling mist out of the air. But how exactly they manage this feat has been a bit of a mystery--until now.

By studying the morphology and physiology of plants with tiny conical "hairs" or microfibers on the surface of their leaves, such as tomatoes, balsam pears and the flowers Berkheya purpea and Lychnis sieboldii, a team of researchers in Japan uncovered water collection-and-release secrets that may, in turn, one day soon "bioinspire" a technology to pull fresh water from the air to help alleviate global water shortages....."

https://www.eurekalert.org/pub_releases/2015-03/aiop-mpm032415.php

It has a video of this process.

P.S. Molds and fungi are pretty hairy , so they should be able to drink from air.