Many use organic fertilizer and others use chemical fertilizer. Everyone wants the same kind of results out of our favorite fertilizer. We all want healthy plants.

"Nitrogen (N) – Nitrogen is largely responsible for the growth of leaves on the plant.
Phosphorus (P) – Phosphorus is largely responsible for root growth and flower and fruit development.
Potassium (K) – Potassium is a nutrient that helps the overall functions of the plant perform correctly.

Read more at Gardening Know How: Fertilizer Numbers – What Is NPK

Phosphorus is a component of most fertilizers that helps plants to grow . When too much is applied or is applied at the wrong time—such as right before it rains—most of it is washed away and ends up in the local waterways. This type of pollution is called nonpoint source pollution.

“Organic phosphorus fertilizers come primarily from mineral sources, like rock dust or colloidal phosphate (also called “soft phosphate”), or from bone sources, such as steamed bone meal or fish bone meal . Mineral phosphorus sources are cheaper and last longer in the soil.”

" Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. Wikipedia

Symbol: N

Atomic number: 7

Atomic mass: 14.0067 u

Electrons per shell: 2,5

Electron configuration: [He] 2s22p3"

“The word potassium stems from the English “pot ash,” which was used to isolate potassium salts. We get K from the name kalium, given by the German chemist Martin Heinrich Klaproth, which stemmed from alkali, which stemmed from the Arabic al-qalyah, or “plant ashes.”

"Potassium is the chemical element with the symbol K and atomic number 19. It is a silvery-white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. Wikipedia

Symbol: K

Atomic number: 19

Atomic mass: 39.0983 u

Van der Waals radius: 280 pm

Electronegativity: 0.82

Boiling point: 1,398°F (758.8°C)

Electron configuration: [Ar] 4s¹"


It is also the component that locks up minerals in clay soils. It is over-promoted because it is in excess in the raw material industries.

The applicability of any fertilizer is very locale and plant dependent. The locale is multidimensional: soil, rainfall, temperature spectrum.


The three legged stool of soil plant interaction is nutrients, cation exchange capacity, and acidity.

I mean there are still a few other important aspects such as plant material handling, how water moves through the soil, the living ecosystem in the soil, and the physical environment where the plant is growing, but understanding the three big ones starts a solid foundation.


This statement is really applicable to Nitrogen. Not so much to Phosphorus, due to it’s low soil mobility. This means that P is readily bound to soil (clay) particles, but also calcium and aluminium in the soil.

Nitrogen however with high soil mobility washes away quickly.
This practically means it’s best to spread out N fertilizations over multiply applications. And when there is active plant uptake. But P fertilizations can be applied much more infrequently.

It’s best to take a soil test and follow their advise.

Or if using an organic source, like compost/manure. If that’s been done on your soil for longer, both P and K are usually build up in the soil to high levels and N might be the only deficient element.

Like don pointed out, there is more at play.
Cation exchange capacity, oversimplified: the ability of the soil to act like a sponge for fertilizers
PH, affecting how easy certain nutrients are to uptake.

But also things like organic matter, Organic matter can act more as an “on demand” source of nutrient due to plant/fungus/bacteria symbiosis.

But is also one of the major reasons for soil tillage’s. The extra aeration that causes, makes bacteria rapidly brake down organic matter, to soluble fertilizers (that can be directly taken up by plants or washed away)
This is called mineralization.

This sacrificing of soil organic matter for short term gain, is a major problem in conventional agriculture. Funny enough though is that orchards due to their lack of soil tillage, are usually high in organic matter and tend to have better soil structure then adjoining plots that where used differently.


They have found some corn that are nitrogen fixers.

“This corn showed us that nature can find solutions to some problems far beyond what scientists could ever imagine.”


Went into additional details here Let's talk about fertilizer but wanted to post a more traditional fertilizer discussion. Here are a few others for reference

Buying commercial fertilizers and pesticides you may be contributing to GHG and the Fossil Fuel Industry.

Currently, the synthetic ammonia for nitrogen fertilizer uses 3-5 percent of the world’s fossil gas but is projected to account for the largest share of the growth in global oil demand through 2026.

over half of fossil gas consumption is expected to go towards producing hydrogen, the key ingredient in ammonia that is the chemical base for nitrogen fertilizer.

Besides contributing to climate change, this excess nitrogen leads to eutrophication (excess nitrogen in our waterways) that results in dead zones that kill fish and other aquatic life.

Could the algae blooms in the water be poisoning waterfowl which in turn has caused the sickness in the poultry industry?

Some unprecedented killing of fish and wildlife lately due to this?


interesting corn and potatoes… are the plants that draw a lot of nitrates out of the soil and are not so popular because you destroy the soil with it and you have to add new fertilizer over and over again.
But corn that fixes nitrogen from the air with bacteria…

we often had the problem that too much nitrate from agriculture got into the lakes and even if the non-toxic algae start to grow, there is a risk that the lake “dies” and the ecosystem collapses

at the face of it, it looks great. A corn that can fixate it’s own nitrogen fertilizer.

However fixating atmospheric nitrogen (our atmosphere is almost 80% N2) Is really energy intensive. I remember reading about clover that it could use 30-60% or something similar of it’s energie just to fixate nitrogen. I can’t find the source now. So don’t trust the 30-60% numbers. But i remember thinking it was a crazy high amount.

Now imagine that corn having 30-60 or some % less energy for growth and corn production. Suddenly not that amazing anymore.

It’s still really cool that they found a corn plant that can fixate N2, especially since most plants that can do that are from the legume family. (and it’s not actually the plant doing it. But more the bacteria that’s in a symbiotic relationship with the plant)

But don’t expect that corn won’t need Nitrogen fertilizations in a few years.

Luckily there are also cover crops that can fixate nitrogen.



Trees like autumn olive as example fix nitrogen as well. It is great picking all those berries and see the soil improve. It has made it to the invasive list now.


i think acacia and a few other tree’s can also. I think i remember though that they fixate a lot less than legume’s.

I personally would like to see more legumes as ground cover under fruit tree’s. Those legumes would not take up the space where a fruit tree could grow. But all nitrogen fixers are important. Bacteria can also produce nitrogen gas. And thus take it out of the soil. Without nitrogen fixers we would slowly loose all nitrogen for plants.

One of the problems though is, that due to the energy intensive nature of nitrogen fixation. Nitrogen fixating plants want to uptake free nitrogen in the soil first. Before fixating it from the air. And thus can actually compete with other plants for nitrogen.

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another hardy bush that fixes N is Siberian pea shrub. i got them growing around my chic run with mulberry planted next to them. the manure with the N fixation should allow those mulberries i planted last summer take off like weeds. pea shrub seed is 30% protein also.

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That sounds really good. Autumn olive have pretty hardy wood. Was out there cutting down a couple today that have done their work. They get over 25 feet tall here.

my 4 named cultivars have grown 4ft. last summer in poor soil. the chic manure i mulched them with last spring was the ticket.

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While I bloody hate dandelions (I got millions of them all around) I do appreciate that they are nitrogen fixers and make sure I dry and compost any root I pull for the added potassium.

I one time I did dandelion honey with my daughter, it was not a bad substitute. I’m yet to try the root as a coffee substitute, I should try this year.


I watch all of the Stephan Sobkowiak videos The Permaculture Orchard channel… and he plants in trios always with a Nitrogen fixer… i did find it odd that he said that nobody really knows how much Nitrogen is ‘fixed’.

I do woodchips and add horse manure and urine to my things that grow… perhaps im wrong but these things are free to me except for the gas to haul them and the labor of shoveling and wheel barrowing.

This is an interesting read of what you lose by removing leaves and grasses from your property over time.

I am pretty confident that the soil that i grow things in was once covered by forest and trees… so obviously the leaves and decaying wood and litter gave me the soil that i use… i think that putting those same things back on top of the ground just seem the wise thing to do.

I am always amazed when i find a thriving patch of wild blackberries that need nothing but their leaves that fall on the ground to thrive.

The abundant nut trees that need nothing but leaf litter and the goings on by undisturbed ground full of bacterias and fungis.

The fruit trees in the old timers yard or road side that seem to thrive on nothing but the soil they find in long root systems… perhaps rocks and minerals that are being decomposed.

I have a couple of hillsides that are being taken over by autumn olives… seems to be what the birds want to disperse for their own forage. Things are popping up on those hillsides like blackberries and black raspberries and wineberries… future forage for those birds… and maybe the autumn olive is fixing the soil for more things to thrive. I dont grow on or use those hillsides… but nature has found a way to use it…and none of it needs my NPK.


I was looking for the nitrogen-fixing corn.
a spanish study showed you could save 30-40% nitrogen,

but there was a big but behind it. the experiments were mostly attempted in tropical, subtropical or mediterranean areas. and it is still unclear whether the bacteria have much disadvantage and draw other nutrients.
and in order to provide accurate results, other analysis methods must be used

many other methods are tested instead of just legumes.
e.g. B. other non-symbiotic bacteria in the soil can fix nitrogen and release it to the plants.

According to the article, only 30% to 50% nitrogen is taken up by plants, but genes are being identified that make some plants take up nitrogen more efficiently.

In a very complicated experiment, one tries to get wheat to enter into a symbiosis with nitrogen-fixing bacteria.

Attempts were also made to introduce the genes for which the enzyme nitrogenasea produces functionally into plants

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My soil tested totally lacking in Boron. So I bought a plastic bottle of Boric acid, ( ant and roach poison) and added it to the pile of wood chips I compost every spring.

I visualized my half-rotten pile spread out on the ground maybe an inch or so thick, guesstimated the square footage and added the stuff dissolved in water at recommended rates for soil of that square footage. About half the recommended amount on top, then a couple of weeks later, turned it over and added the other half.

Turned out to be a teaspoon or less on each side.

As to P, I’ve about come to the conclusion that deliberately adding P to U.S. soils is a big fat waste. I wouldn’t do it on purpose without a soil test.

My bottle of Boric acid will last me a very long time.

Beyond the initial hot composting phase I try to make regular additions of Urea to my pile of wet wood chips in what I consider to be biologically plausible amounts: Maybe an ounce or so dissolved in a five gallon bucket of water. About like animal urine in that amount. I figure a pile that started out as a big pickup load of chips can chew on that amount of N without environmental damage for a very long time.

If I had easy access to chicken litter I would use that and probably not bother with anything else other than the chips.