10 questions and answers about dolomite flour


Dolomite flour is one of the popular natural fertilizers. She is very respected by summer residents, who sometimes use it exclusively on their sites. This fertilizer is used both as a deoxidizing agent, and as a full-fledged fertilizer containing trace elements, and also as a substance that can fight against a number of weeds (in the form of mulch), and even with some types of insects (for example, the Colorado potato beetle). In this article, we will answer the 10 most popular questions about dolomite flour.

Dolomite flour is one of the most popular natural fertilizers.

1. What is dolomite flour?

This powder, made from dolomite, that is, a carbonate crystalline mineral, is either snow-white or gray. In some cases, it may have more contrasting shades, but the reason for this should be indicated on the package - perhaps the manufacturer included additional components in it. As a result of crushing, very fine sand is obtained, which is called powder or more often - flour.

Dolomite flour owes its wide distribution to a low price and a very gentle effect on the soil. If we take slaked lime as a similar element, which is preliminarily enriched with calcium and put into the soil, then it is considered more “harmful” because it does not allow different crops to adapt so quickly to the actually new soil conditions that the lime “creates”.

As for wood ash, the “harmful” effect is minimal, but it is often extremely difficult to choose the optimal dosage of ash due to the very fluctuating composition of this type of fertilizer, depending on the initial combustion product (wood species, etc.).

2. What are the properties of dolomite flour?

As we have already indicated above, the properties of dolomite flour make it possible to use it as a good fertilizer, as a deoxidizing agent and as a “preparation” for controlling harmful organisms and even certain diseases (for example, rot).

Dolomite flour is most often used precisely because of its ability to deoxidize the soil, so flour is usually applied to soils that are highly acidic, which are simply unsuitable for growing most crops.

Thanks to the introduction of dolomite flour, the growth and development of plants improves, and many fertilizers that are bound and inaccessible to plants in acidic soil become quite accessible to them, that is, the nutritional value of the once acidic soil increases.

Directly in the composition of dolomite flour, the dominant components are magnesium and calcium. When introduced into the soil, magnesium favorably affects the photosynthetic processes of plants, and calcium stimulates the growth and development of the root system.

Dolomite flour is perfect for such vegetable crops as table beets, potatoes, onions and carrots, thanks to its introduction fodder herbs and even berry shrubs and trees, especially stone fruit crops, grow better.

Dolomite flour can be used both for enrichment of open and protected soil, and it is often used by lovers of indoor plants. Usually, in addition to acidic soils, dolomite flour is used on sandy loams and sandstones, soils with a deficiency of magnesium.

3. What is the effectiveness of dolomite flour?

Due to the effect of neutralizing the acidity of the soil, plants receive the necessary elements from the soil and fully develop, the soil itself becomes better in its structure, its biological and chemical compositions improve, the nutrients in the soil are completely redistributed and the amount of plants necessary for them is improved.

The introduction of dolomite flour allows you to accelerate metabolic processes in the body of plants, improve the photosynthetic apparatus. Harvested from sites where dolomite flour was also used as fertilizer, is stored longer and its palatability is better. All this is achieved due to the ability of dolomite flour to stimulate the growth and development of the root system of plants and increase their immunity.

Dolomite flour is made from dolomite, a carbonate crystalline mineral.

4. How to determine the acidity of the soil for making dolomite flour?

It is necessary to plan the introduction of dolomite flour after determining the composition of the soil, that is, determining its acidity. Dolomite flour, if the soil is closer to alkaline in pH, can cause some harm, enhancing the alkaline reaction of the medium.

See also our detailed article: Soil Acidity - How to Determine and Deoxidize.

Soil acidity is determined in different ways, and the pH level is contained in a digital "code" from 0 to 14, the smaller the number, the soil is acidic, and the larger the number, the more alkaline it is. It is clear that somewhere in the middle is a value indicating a neutral reaction of the soil.

It is better to determine the acidity of the soil in the laboratory, collecting samples from different places of the site, literally 100 grams in each sample. You can determine it yourself, but in this case it is quite easy to make a mistake.

The most accurate "home" definition of soil acidity is using a set of litmus papers (often orange) and a scale on which acidity levels are marked in different colors - red, which means the soil is acidic, green is neutral, and blue is alkaline.

This kit can be purchased at a garden store. You need to take a handful of earth and stir it in a glass of water, then, when the turbidity settles, lower the litmus test into the solution. Next - hold for 15-20 seconds, remove from water and compare the color of the paper with the color on the scale, so you determine the acidity of the soil.

If there is no litmus test at hand, and you need to determine the acidity of the soil, then you can do this literally by your observations. To do this, carefully examine your site, if plants such as woodlice, plantain, chamomile, dandelion, coltsfoot, nettle and quinoa grow on it, then you can safely use dolomite flour, because the soil requires deoxidation.

5. How to make dolomite flour?

After you determine the pH of the soil and realize that it is not alkaline, you can proceed with the introduction of dolomite flour. About its quantity: try to focus on soil acidity, for example, with soil acidity of 4.0 or less, that is, when the soil is acidic, it is permissible to add 60 kilograms of dolomite flour per hundred square meters. If the pH is in the range from 4.1 to 5.0, this indicates that the soil is medium acid, then the "dose" of fertilizer can be reduced to 50 kilograms per hundred square meters of land. If the pH is from 5.1 to 6, then this is a slightly acidic soil, and if you use dolomite flour as a deoxidizing agent, then about 30 kilograms of dolomite flour can be added to a hundred.

It is also necessary to focus on the type of soil: for example, on loams and alumina, the amount of fertilizer for all types of soil acidity can be increased by 20 percent, but if the soil is light in mechanical composition, then it can be reduced by the same volume (in%).

On average, for a standard six hundred square meters, a summer resident needs from 250 to 400 kg of dolomite flour, extremely rarely when more. By the way, the cost of dolomite flour is low, and if you take into account that they make it once every four or even five years, then you are unlikely to notice this money at all.

But not only dolomite flour in its pure form can be applied to the plot, it is quite acceptable to mix it, for example, with compost, copper sulphate or add a couple of grams per 10 kg of boric acid flour to the composition.

6. When to add dolomite flour?

This fertilizer can be applied at the beginning of the season, both before planting, and simultaneously with them, and at the very end, until November.

It is good to sprinkle dolomite flour directly on the surface of the soil, as soon as you harvest, such a simple agricultural technique will not harm cultivated plants in the future, but will allow the soil to restore its strength in some way.

7. Are there any opponents to the use of dolomite flour?

Oddly enough, but there are opponents of this method of fertilizing the site. And almost all opponents of dolomite flour do not bring it to the site just because of the higher price than that of slaked lime. Maybe lime is really better and not worth overpaying? Let's look into this issue.

So, let us recall the form in which calcium is found in lime. That's right - in the form of hydroxide, hence the more aggressive effect on the soil, but in dolomite flour calcium is a carbonate, therefore, it is even slower, but it changes the acidity and composition of the soil more accurately (gently).

Therefore, individuals who, by and large, don’t care what’s going on with the soil, the main thing is to have a lightning fast result, can add lime, but do not forget that by changing the composition of the soil at such a high speed, you risk get a smaller crop, lower quality indicators, modest storage periods, and assimilate the nitrogen and phosphorus of the plant (when making lime) will be much weaker than when making dolomite flour.

Here, of course, it is worth making a reservation that the benefit will be only with moderate doses. For example, if you add a ton (!) Of dolomite flour to six hundred square meters, then it can also bind phosphorus in the soil so that it does not reach the plants at all.

What do we have in the end? Those who were in a hurry to change the acidity of the soil and applied lime should now give the soil at least a year to rest, but those who used dolomite flour already grow wonderful plants on this site. Although instant deoxidation did not occur, the soil became “digestible” for plants without any period of “waiting”.

When making dolomite flour, like any other fertilizer, it is important to comply with the rules.

8. How to make dolomite flour for different crops?

Let's start with the vegetables. For most crops, dolomite flour will be useful and you can add it at the beginning of the season, at its height and at the end; but, for example, potatoes can react negatively to the introduction of dolomite flour, so before applying under the potato, make sure that the soil is really acidic or medium in acidity. Then dolomite flour can be added safely, it can minimize the infection of potatoes with scab, increase the starchiness of tubers and even reduce the number of Colorado potato beetles, for which powder of flour needs to be scattered directly on the soil surface of the entire area where the potatoes grow.

We go further. Wild strawberry. Pure dolomite flour is rarely made under it, usually it is mixed and added at the very end of the season. About one and a half tablespoons of nitrophoska mixed with 300 g of wood ash and 200 g of dolomite flour are needed per square meter of strawberry beds.

Fruit crops, in particular stone fruits that respond so well to dolomite flour, they like top dressing at the very end of the season, in this case, a kilogram of one and a half dolomite flour can be added to each plant. As for fruit crops, but pome seeds, say, apple trees, dolomite flour can be used once every couple of years, and if the soil is exactly acidic, but if it is close to neutral, then adding a couple of kilograms under each apple tree is enough once every six years.

Shrubs - again autumn application, enough for 500 g per plant, sprinkling it at the very edge of the prikustovogo zone.

Important! Always distribute the dolomite flour on the plot as evenly as possible, of course it is possible to deepen it, but no more than by shovel bayonet.

When it enters the soil, when mixed with its structure, dolomite flour will begin to act immediately, enriching the soil and deoxidizing it, thereby improving the structure of the soil.

9. What threatens an overdose of making dolomite flour?

Yes, with the introduction of dolomite flour, you can also overdo it, and then this can even cause the death of plants. To avoid this, be sure to find out the pH of the soil before applying dolomite flour, if the indicator is above six, then the introduction of dolomite flour is better to postpone for later or use absolutely safe doses, such as 250-300 g per square meter of soil.

Keep in mind that not all fertilizers can be combined with dolomite flour, for example, it is better not to add it with ammonium nitrate and urea, it does not like dolomite flour and fertilizers at the same time as organic fertilizers.

“But what about?” - you will be amazed, - where without organics on a site?

If the introduction of organic fertilizers is an unshakable rule for you, then add them separately, say, dolomite flour at the end of the season, and organic matter in the early spring or just before the snow falls and the frosty season begins.

10. Are there any cultures that do not like dolomite flour?

Yes, those who love acidic soil are the well-known blueberries, sorrel and cranberries.


In general, the introduction of dolomite flour with a high degree of probability will positively affect the state of the soil and your plants. If you do everything, as we advised, then you can increase productivity by a quarter and this is not in one year, but in two or three seasons.

This is all we wanted to tell about dolomite flour, white or gray powder. If you still have questions, feel free to ask them in the comments!