NPK of everything

[Chuck]

N-P-K Value of Everything

 

[Oliver Buckle]

Over here we get two sets of figures on fertilizers, one for the English market, one for the Irish because the Irish insist on the available quantity. The English figure is simply the total, which is deceiving if the plants can't use it.

 

[Chuck]

Over here we get two sets of figures on fertilizers, one for the English market, one for the Irish because the Irish insist on the available quantity. The English figure is simply the total, which is deceiving if the plants can't use it.

Is the availability of nutrients to plants due to the fertilizer being a synthetic fertilizer and not an organic fertilizer?

 

[Oliver Buckle]

Probably, TBH I have never checked on organic fertilizer, I'll have a look in a bit.

 

[cpp gardener]

It's not organic/synthetic, it's available/total. Available can be either organic or synthetic. It depends on the molecules involved.

 

[Oliver Buckle]

So I looked at the container of organic liquid seaweed, nothing. Apart from a lot of guff about how it is very good for your plants and will make them grow better and more resistant to disease there is nothing about what it contains. I think the law may only require inorganic products to say what they contain over here. I'll check on the bonemeal.

 

[Oliver Buckle]

The bone meal is labeled,

UK fertiliser declaration
Bone meal 3-9-0
Total nitrogen (N) 3%
Total Phosphorus 9%
Phosphorus pentoxide (P2 O5 ) 3.9%
-----------------------

RoI fertiliser declaration
Bone meal 3-9-0
Total Nitrogen 3%
Phosphorus (P) soluble in water 0%
Phosphorus (P) soluble in mineral acids only 3.9%

I have some ancient 'Affordable excellence feed for tomatoes' , I bought a bunch of years ago because it was reduced and very cheap.
Fertiliser declaration
Compound fluid fertiliser NPK 2.0-2.5-4.5
Nitrogen total 2%
Phosphorus pentoxide P2 O5 total 2.5% ( 1.1%P)
Phosphorus pentoxide (P2O5) soluable in water 2.5% (1.1% P)
Potassium oxide (K2O) Total 4.5% (3.7% K)

Fertiliser declaration IRE
Low nutrient fertiliser NPK compound 2.0-1.1-3.7
Nitrogen (N) total 2.0%
Ureic nitrogen 1.3%
Phosphorus(P) soluble in water 1.1%
Phosphorus (P) soluble in mineral acids only 1.1%
Potassium (K) soluble in water 3.7%

The UK govt. lets you 'big things up' by including everything, the Irish only want to know the relevant stuff, sounds about right
I suppose this is % by volume, but it is purely supposition, there is no indication.

 

[Oliver Buckle]

I was thinking about the liquid seaweed. The bone meal shows the npk just like the artificial, as though any fertiliser must show it. But when I look at the seaweed it doesn't actually claim to be a fertiliser.

 

[Chuck]

I was thinking about the liquid seaweed. The bone meal shows the npk just like the artificial, as though any fertiliser must show it. But when I look at the seaweed it doesn't actually claim to be a fertiliser.

A fertilizer has NPK. The liquid seaweed does not, at least here in Texas. All it has is micro-nutrients, zero macro-nutrients.

 

[Oliver Buckle]

I guess that's it then. I can't exactly remember where I got it, I had a couple of bottles, I think it was half price somewhere. Most of the stuff I use is going cheap or free. One of my favourite things to hear is "We were tidying the shed and wondered if you could use ..."

 

[Chuck]

It's not organic/synthetic, it's available/total. Available can be either organic or synthetic. It depends on the molecules involved.

The availability of organic fertilizers depends on the numbers and types of SOIL MICROBES that are in the soil. Organic fertilizers do not feed plants directly, they feed the soil microbes. These microbes change the fertilizer into a form the plants can uptake. This means that a perfect soil will make 100% of the organic fertilizer available to plants. Synthetic fertilizers feed plants directly and do nothing for the soil, thus the need for availability numbers on synthetic fertilizers. I wish we had the same packaging rules that the Irish do.

 

[Oliver Buckle]

The availability of organic fertilizers depends on the numbers and types of SOIL MICROBES that are in the soil. Organic fertilizers do not feed plants directly, the soil feeds the plants. Synthetic fertilizers feed plants directly and do nothing for the soil.

Statement like this always worry me a bit, what does 'Organic fertilizers' mean? Would wood ash count? The potash can wash straight out of it and be directly available to the plant. What counts as synthesis? If things are isolated and concentrated from natural sources are they still 'Organic', or have they become 'Synthetic', for example processed sea bird shit, or fish blood and bone, or is it just when the nitrogen is artificially fixed from the atmosphere? And if artificials feed plants and the main body of the plant is composted back into the soil then surely they are adding something to the soil? And what about the plants that live in the soil, it is not just microbes.
It's the 'This good, that bad' attitude, things are hardly ever that simple and phrases that allow a bit of leeway, like "You are probably better off staying as close as practicable to the natural course of events." appeal much more. Let's face it, without those polluting synthetics a good few million people would have starved to death, they have done some good.

 

[Chuck]

Statement like this always worry me a bit, what does 'Organic fertilizers' mean? Would wood ash count? The potash can wash straight out of it and be directly available to the plant. What counts as synthesis? If things are isolated and concentrated from natural sources are they still 'Organic', or have they become 'Synthetic', for example processed sea bird shit, or fish blood and bone, or is it just when the nitrogen is artificially fixed from the atmosphere? And if artificials feed plants and the main body of the plant is composted back into the soil then surely they are adding something to the soil? And what about the plants that live in the soil, it is not just microbes.
It's the 'This good, that bad' attitude, things are hardly ever that simple and phrases that allow a bit of leeway, like "You are probably better off staying as close as practicable to the natural course of events." appeal much more. Let's face it, without those polluting synthetics a good few million people would have starved to death, they have done some good.

Wood ash does count as an organic fertilizer although a very weak one. It has zero nitrogen, maybe 1% phosphorus at maximum and about 4% potash. It will be instantly available to plants IF there are enough of the right kind of soil microbes available to change the potassium into a form plants can uptake of which most soils have an ample number of these microbes. Guano or blood, bone are good sources for nitrification. The soil microbes break down the organic wood ash, guano or blood and bone into forms available for plant uptake. Ammonium is released during this breaking down process which is then quickly turned into nitrates by the nitrification process. That is where the nitrogen comes from in organic fertilizers. Synthetic fertilizers are man made from byproducts of the petroleum industry. And yes, plants grown from synthetic fertilizers do break down into useable forms if there are sufficient soil microbes available. But, after years and years of using synthetic fertilizers one finally has depleted the microbe numbers to the extent that the soil is actually dead. Thus all of the "worn out farms" all across the US. You mentioned "plants that live in the soil, it is not just microbes". If soil is dead and does not have enough microbes even weeds will not grow, but if you add enough synthetic fertilizer plants will be lush. But, the cost of doing this rises as more and more synthetic fertilizers are needed and at the same time the soil microbes are vanishing. Just look at Ukraine where a lot of the worlds fertilizers are made. Already the prices for synthetic fertilizers is going through the roof. A lot of the Mega Farms in the US have their own fertilizer plants but even they are feeling the increased costs. But on a brighter side many farmers now are starting to go to a form of organic farming, not totally, but a start. They are finding that the increased costs of organic fertilizers is offset by not having to use as many pesticides. And they are learning that organic fertilizers stay in the soil MUCH longer than synthetics. And this means that as the years go by less and less fertilizer is required for the same amount of product, the exact opposite of synthetic fertilizers. If you like you can do a little research by studying something called CEC or cation exchange capacity. It explains a lot about the differences between the fertilizers.

 

[cpp gardener]

And yet dead and decaying plant roots and stubble DO count as organic matter in the soil. Synthetics do not kill the micro-organisms that decompose organic matter. Organic fertilizers do not decrease the need for pesticides. Oliver has it right that it really isn't either/or and a combination of practices is more effective, although either one works fine separately.

 

[Chuck]

And yet dead and decaying plant roots and stubble DO count as organic matter in the soil. Synthetics do not kill the micro-organisms that decompose organic matter. Organic fertilizers do not decrease the need for pesticides. Oliver has it right that it really isn't either/or and a combination of practices is more effective, although either one works fine separately.

Yes, all plant matter is organic in nature. And synthetics do not kill micro-organisms, they just slow down their reproduction to the point of extinction. Pesticide use in organic farming is limited to non-ecologically damaging pesticides., such as Bt, Neem, Spinosad and Pyrethrin. These pesticides quickly disappear, mainly from sunshine and do not leave a residue on the product. And the scientific answer is still out on if the use of organic fertilizers reduce the need for pesticides or not but, in my experience of growing both organically and with synthetics I unequivocally state that organics lead to very few pest problems. In fact, the only pesticide that I have had to use regularly is Bt. I just rarely ever get insects of any kind. And of course both organic and synthetic means of growing plants is fine if you don't take into count what synthetics are doing to our waterways and ground water with their high nitrogen/phosphorus content. Just look at the algae bloom in Lake Erie, the Mississippi River all the way 300 miles into the Gulf of Mexico. And everywhere in between. The only reason I can think of to use synthetic fertilizer over organic is that synthetic fertilizers are faster acting than organics. But this faster acting is limited by the length of time synthetics stay in the soil or are used by the plant. Synthetic fertilizer molecules are negatively charged. Organic fertilizers molecules are positively charged. Soil particles are negatively charged. Opposites attract, cling to one another, while negative on negative repel each other. This is why there is so much pollution when using synthetics, they do not adhere to soil at all and just wash away. Ever wonder why synthetic fertilizers have such high NPK numbers? You are paying money watching your synthetic fertilizer wash away each and every time you water or it rains so it is imperative that enough stays around out of a 40lb bag to do its job. And then you have to worry about applying too much and damaging your plants. Not so with organic.