Ash fertilizer

[NicolasGarcia]

Hi all!
I have a fireplace at home that I use a lot in the winter months, I use olive wood because where I live is where more olive oil is produced in the world and there are many olive trees and easy to get. I would like to know if this ash from the fireplace will be used to add it to my garden for the fertilizer and how much ash would be suitable.
For the fertilization of my garden I use earthworm humus, cow manure and straw and dry leaves every year.
Thank you so much
Nico

[NicolasGarcia]

Popular wisdom has always considered ash as a product that benefits plants, but is it really like that? Do we benefit our organic orchards or fruit trees by spreading the ash from our chimneys? Let's know the chemical properties of ash and its possible uses in the field as natural fertilizer.
What chemical composition has the ash and what is its potential fertilizer?
First of all, we have to know that with the combustion of firewood, we consume almost all organic carbon, remaining in the resulting ash mainly Calcium, potassium, aluminum, magnesium, iron, phosphorus and manganese.

But it is calcium and potassium in the form of carbonates which we mostly find in wood ash. This made it a highly prized product as a source of potassium and calcium amendment before the chemical synthesis of fertilizers.

Another relevant aspect of wood ash in the soil is its effect on soil reaction (PH). The ash is highly basic, and causes a rapid increase in soil pH. For acidic soils this is very interesting, since it unblocks nutrients and helps to correct its acidity, bringing it closer to the most correct levels for the majority of cultivated species. But in basic soils it can bring us problems.

So, at the level of macronutrients do we have to consider ash as a source of calcium, potassium and phosphorus?

Apparently yes, but no. And in most floors of Spain we can say flat NO. The majority of soils cultivated in Spain, especially those of the Mediterranean coast, are of basic reaction, with high levels of limestone. In these soils, the contribution of ash can be harmful, as providing more carbonates can increase the blockage of nutrients such as potassium and magnesium due to the high proportion of calcium in the soil, as well as the inherent blockage of certain nutrients by raising the PH. The typical case is the Iron, which in basic soils passes to forms not assimilable by plants and causes severe chlorosis even having acceptable levels in the soil.

On the other hand, in areas with high rainfall (Cantabrian cornice, Basque Country, Galicia, etc.), the large amount of rainfall leads to more acid soils. There, if the moderate contribution of wood ash is beneficial.

Beware of ash: Only wood!

We have to be very careful with the quality of the ashes we use. Burning in the fireplace other things that are not firewood, can end up manufacturing a compound potentially very harmful to health and the environment. I mean that if in it we burn papers (from magazines, newspapers), serigraphed cardboard, remains of furniture, wood from pales etc.. The resulting ash will be a highly toxic heavy metal concentrate. Varnishes, paints, inks, etc., use, although in small quantities, heavy metals. By burning these materials heavy metals do not disappear, but accumulate in the ash. So, depending on what we burn that ash is totally inadvisable for our organic garden or orchard.

conclusion
We are aware that what we have proposed contradicts what popular wisdom proclaims, and that can always lead to controversy. We have only tried to objectively present the subject, and we think that in the vast majority of cases, the harmful effects of the ash can greatly overcome the positive effects of the latter on the ground. But like everything in life, the dose is the key, so if you use ash regularly, it is in small quantities. And if the soil of your organic garden is limy, our recommendation would be to avoid its use.

[bower]

That's a very nice link, Nico, and an interesting subject. We have acid soils here, so ashes can be a plus but it's always a challenge to decide how much to apply, with a substance that can affect pH so dramatically. When I burned wood to heat my home, I mostly used the ashes in my compost, and let them contribute to that process. Since it rains a lot as time passes, the pH issues are resolved before the compost is ready to use.



One thing I learned, it is important to use very fine ashes from complete combustion, and avoid using coarse ash with bits of charred wood, which also contain creosote and can be toxic to plants.

[MrBig46]

Every autumn I burn some wood in the garden and I use ash from it for fertilizing. No creosote is not in him even though there are some not burn the remains. This year I have three wheels of this ash. I put one ash wheel on the compost and the other two stored for future use (on all beds I already had a splintered ash from the past).
Vladimír
PS.: I burned on Thursday - the only day I can burn in the afternoon. I had a lot and ended up in the dark.

[NicolasGarcia]

Thank you very much for your advice.
I think I'm going to buy a test that measures pH, nitrogen, phosphorus and potassium, and from then on I'll add ash, I hope the test is reliable ...
Nico

[Nan_PA_6b]

Nicholas, I agree with you. Test your soil pH. If it is acid, use some ashes.
Nan

[NicolasGarcia]

Originally Posted by Nan_PA_6b

Nicholas, I agree with you. Test your soil pH. If it is acid, use some ashes.
Nan

Thank you .
I hope the test is reliable

[NicolasGarcia]

Although I think that if I burn the ashes now and the time passes and it rains, maybe it will neutralize a bit ... the truth is that I do not know

[bower]

I need to get a pH test kit too. Guessing is hard! and you never really know for sure. My impression is that ashes do raise the pH dramatically but it also falls more rapidly than when you apply lime. We are very short of calcium in the soil here, so perhaps it is just that for our soil, it is more critical to apply calcium. Or perhaps there is something in our soil that binds to the potassium after it rains, and takes away the pH effect.

[zipcode]

My grandma used to collect all the tree pieces after trimming trees etc, and pile them on the soil in one place in autumn (when everything is harvested). And then burn them. That place where some fairly high amount of ashes was, made great potatoes next year.
I think it takes quite a bit of ash to really change the pH long term, so unless your ph is already high you're probably good to go.

[Worth1]

For a reference you can and they did make lye from wood ash.
Lye is so alkali that it will strip the hide off your body.

Worth

[bjbebs]

Nicolas, I think everything you are doing for good soil health is working. Leaves, straw and manure will bring and keep the worms. If you have worms, your soil is providing what your plants need.
I also heat with wood, mostly oak, ash and hickory seasoned for 2 years. All the ash from the burner goes on the garden, stock tanks and other containers. Also the ash is mixed into the compost piles. After decades of using ash my plants tell me they like it.
By all means do a soil test if you are unsure, but I think your soil structure is in good shape. A soil test will tell you where you're at before adding ash. I think after a couple years of using ash and then do a test you would find little if any change. Soils tend to find the right balance as long as you continue using leaves and manure.
I hope this translates for you.

[NicolasGarcia]

Thank you very much everyone for your advice, this year I will buy this test to analyze the earth.
Even knowing that my land has all the nutrients necessary for the proper development of my vegetables, I will try this test out of curiosity

https://www.manomano.es/abonos-y-fer...del_id=7503208
Nico

[velikipop]

I also use ashes from my fireplace as a soil amendment and have not seen any negative effects, however, I just read in a book on composting that ash added to compost might leech out the beneficials and nutrients because of its high ph. I suppose it depends on how much is used in compost.

[bower]

I know that ash is popularly used just by sprinkling around your plants to deter slugs and snails. I'm not sure if it works but haven't heard of it causing harm to the plants - obviously in small amounts. Ashes in compost are also purported to deter rats - maybe it masks the smell of the things that attract them.
Coincidentally I was reading about the use of ashes in natural dyeing, as a means of raising pH, where it was reported that the pH dropped steadily over several days and sometimes unexpectedly when (ash water) was left in a container for several days.

To my mind it confirms that the pH effects are fairly unstable (certainly to heat, maybe also to ?? oxygen? re pH declining in a container of 'lye water'. ) but of course in soil the interactions are different. I do think that rain and watering can change those pH effects pretty quickly.


The recipe given was 1 kilo of birch ashes to which 8-10 liters of boiling water is added, then left to stand for 24 hours - the liquid becomes yellow and was measured to have pH 10 after one day. So it can certainly be a strong alkali in the short term.