Le Potager du Sloth: Gardening without fatigue more than Bio

[to be chafoin]

A contribution of 40 gross tons / ha every 3 years [an average dose, today very little practiced! This is the equivalent of 4 kg / m² in the kitchen garden, ie 400 kg on 100 m²] brings about 350 units of P. It is indeed, quite significant and corresponds to the needs of the 3 cultures that will succeed one another.

I do not know agricultural measurement units at all and it always seems to me like another planet, can one really apply agricultural calculations to ridiculous dimensions compared to our vegetable gardens (which themselves are large or medium vegetable gardens .. but try to push the cipher to the end to compare with the lowenfels thresholds, chick! ...
In addition it will make me revise my memories (which seem to me so old ) of terminal S!

First of all you have voluntarily enlarged I imagine (?) The result?
3.5 units of P / ton * 40 tons = 3.5kg * 40 = 140 kg of P contributed by ha = 140 units / ha (and not 350 ???).
But sorry I am probably confused with the agricultural measures and I am not sure at all: you say "350 units of P" = 350kg of phosphorus for a ha, is that it?

Let's assume if you take your number as a precaution: 350 kg / ha = 35 mg for 1m2 (because 1ha = 10000m2).
For the rest I do not know how many kg of land can be counted m2 (I imagine that if we do not bury too much manure, phosphorus remains in the first 10 cm .. ) but that corresponds to a few kilos I imagine..Disally 3 (but it must be more!) So we would 35mg / 3 = 12mg / kg and so we would be, counting wide, and the wet finger, at 7 times below the threshold given by Lowenfels (80mg / kg).

By the way, when you say 4 kg / m2 it's about a good shovel by m2 every 3 years is that?

[Did67]

I do not know agricultural measurement units at all and it always seems to me like another planet, can one really apply agricultural calculations to ridiculous dimensions compared to our vegetable gardens (which themselves are large or medium vegetable gardens .. but try to push the cipher to the end to compare with the lowenfels thresholds, chick! ...
In addition it will make me revise my memories (which seem to me so old ) of terminal S!

First of all you have voluntarily enlarged I imagine (?) The result?
3.5 units of P / ton * 40 tons = 3.5kg * 40 = 140 kg of P contributed by ha = 140 units / ha (and not 350 ???).
But sorry I am probably confused with the agricultural measures and I am not sure at all: you say "350 units of P" = 350kg of phosphorus for a ha, is that it?

No no !

a) I love "shock formulas" but I don't "distort", unless I'm mistaken, the data.

In this case, the manure that is spread is usually decomposed manure, which has lost some of its carbon, where P has concentrated. In my book, for decomposed manure, I give a grade of 9 units per ton.

b) But no it is not 350 kg of P.

Agronomists reason in "fertilizing units", based on great-grandfather chemistry .... But all the tables, the labeling of fertilizers, the needs of plants are expressed like that!

Has been agreed once and for all (and therefore despite common sense!) That:

1) 1 unit of N is 1 kg of N

2) 1 unit of P is 1 kg of P₂O₅. It is therefore necessary to convert the quantity of P present in equivalent quantity of P₂O₅.

When in a fertilizer there is 1 kg of P (of atoms of P), one displays as if this P was in the form of P₂O₅, and so we display 2,29 unit of P expressed in P₂O₅ !!! On the bag, there will be marked 2,3 (rounded).

But if the pdt absorbs 1 kg of phosphorus (in the form of phosphate ions), we will write in the tables that the "need" is 2,3 units of P expressed in P₂O₅.

We see that in the end, it comes down to the same!

3) For K, the unit is 1 kg of K₂O. The conversion factor is then 1,2: in 1,2 units of K₂O, there is only 1 kg of K.

So much for the units. This dates from the time when we were still groping about soil chemistry, very exactly, to analyze, we extracted the element in question in one of the forms of oxides, which we weighed ... Hence the "laziness" to convert. We used the raw data of the weighings as "units".

Today it is the other way around. I have "converted" a lot of data to make the table, because one finds rather analyzes which give the contents in P, or in K, etc ... [And in the internetic literature, there are many errors of thereby]

[Did67]

Let's assume if you take your number as a precaution: 350 kg / ha = 35 mg for 1m2 (because 1ha = 10000m2).
For the rest I do not know how many kg of land can be counted m2 (I imagine that if we do not bury too much manure, phosphorus remains in the first 10 cm .. ) but that corresponds to a few kilos I imagine..Disally 3 (but it must be more!) So we would 35mg / 3 = 12mg / kg and so we would be, counting wide, and the wet finger, at 7 times below the threshold given by Lowenfels (80mg / kg).

By the way, when you say 4 kg / m2 it's about a good shovel by m2 every 3 years is that?

No no !

a) 350 kg (kilo) on 10 000 m², this makes 35 g (0,035 kg) per m².

So 1 000 times more.

b) In addition, the ground is not "virgin" in P, this one is adds to the P already present. Who is not leached! Mushrooms do not make a difference!

(c) On the other hand, even if it is not leached, it is distributed in a much larger volume, albeit in a non-uniform manner.

Let's assume 30 cm (all theoretical). That is, per m², 1 / 3 of m³ of soil.

An order of magnitude of apparent density of a dry soil is 1,3 (it varies from 1 to 1,6 for mineral soils).

So we are at 0,3 * 1,3 t = 2 tons per m².

d) Let's summarize: this makes a contribution of 35 g of P₂0₅, therefore 35 / 2,3 g of P = about 15 g of P.

In about 2 000 kg of earth.

So 15 000 mg of P / 2 000 kg of soil = 7 mg of P / kg of soil.

We would indeed be far away.

[Provided that Lowenfels did not confuse unit of P2O5 and kg or g or mg of P !!!]

e) Yes, these are contributions as they are practiced in agriculture, with spreaders ...

A "good" gardener puts much more!

[to be chafoin]

Oh yes, I really have to go back to school!
Thank you for the calculation. But 2tits that seems to me huge for the 30cm of 1m2 of surface of soil! You're sure ?
If it's good, we would be at least 10 times below the threshold (s). And this phosphorus will be synthesized integrally by the plants on the next 3 years?

[JardinierAmateur]

Hello to all lazy friends .... or should i say phenocultors ??

I will have two small questions please.
I had two pink Roscoff onions in my pantry that dragged me away. Become unfit for consumption. So I told myself that I was going to try to get some seeds. So I put them in the ground. And I have seen bulblets grow, 4 or 5 by onion, and stems to be made.

First question: on one of the plants, the stems have completely disappeared, what could have done that? Slugs? All was well until then, but it rained recently, I had just watered the hay, and I had seen some slugs return.

Second question: I therefore have 4 bulbils stuck together (with only one onion), each with a stem. I would like to draw some seeds. How to do ?

Thank you

[Did67]

Of two things one:

a) your onions have "gone through" enough cold / sufficient rest period; they think they are in year 2 and will flower [it's a biennial]

b) they were not cold enough; they "think" they are in year 1 and will grow vegetation; in this case, you leave them in the ground and next year, you link the a) !!!

Slugs like enough onion leaves; so it's a very serious assumption!

[JardinierAmateur]

Ok, thank you Didier! So nothing to do, I let it grow, and I will have my seeds this year or next year ....
For slugs, I did not think they would eat onion anyway! But I really do not see what else it may be ..... so go surround my last foot of ferramol .... Think that the few bulblets that are earth and have no stem go into to redo one?

[Did67]

But 2tits that seems to me huge for the 30cm of 1m2 of surface of soil! You're sure ?
If it's good, we would be at least 10 times below the threshold (s). And this phosphorus will be synthesized integrally by the plants on the next 3 years?

a) From this we can see that it is illusory to want to "improve" the texture (the sand / silt / clay contents) of a too clayey soil by adding sand or, conversely, of a too sandy soil with clays. Except being a truck driver.

A "normal" dump truck is 12 tonnes!

b) For P, the soil generally contains a large stock. But a small part is available for plants. There are permanent exchanges between the soil solution (the "soluble" P; in fact, the phosphate ions) and different salts which "precipitate": calcium phosphates, ferric phosphates, aluminum phosphates (depending on the pH). .. And indeed, the plants and organisms of the soil use, for their needs, rather in the soluble part… There is thus permanent exchanges between these various forms of phosphates and these various “reservoirs”.

The P is therefore very poorly reasoned in "it suffices to bring to the soil what the plants take from it" ...

These "retrogradations" (hiding in an insoluble or inaccessible form between the clay sheets) is to P what leaching is to N.

And the spectacular role of mycorrhizae is to find and mobilize it where it has hidden!

It is undoubtedly for the P that there is the strongest gap between the classical reasoning (the ground is a "fridge", it is necessary to put what the plants take there) and the reasoning in a living ground (it It is necessary to favor the mycorrhizae which will be able to find the P, as long as they are not bothered, and make it available to the plants). The day and the night...

[Did67]

Think that the few bulblets that are in the ground and have no stem will make one again?

I am not sure of myself, but "thinking" for others does not cost a lot: I think so!

[Did67]

About Lowenfels ...

Somewhere, but I can't find where, I answered wrongly to "be a jerk (it seems to me): I have just discovered that he wrote a book on mycorrhizae. Until then, I only knew his book" A living soil ", wrote with Lewis, and whose ending I find" absurd. "I don't have (not yet) the one on mycorrhizae. I thought that was where the quote came from (not remembering that what interests me is that often I do not remember certain passages - so I was not surprised).