Acidic soil: definition and control methods
Acidic soil is the least preferable for growing cultivated plants. The acidity indicator is determined by the number of hydrogen ions.
How to identify acidic soil
Representatives of vegetable and garden crops do not grow on acidic soil. The exception is soil with an acidity level close to neutral.
Source: Depositphotos
Determine acidic soil by plants on the site or using special indicators
Methods for determining acidic soil:
- By plants. High pH levels ≥ 7 are preferred by moss, heather, horsetail, ferns. Lilies, roses, irises and delphinium also grow in such areas. At pH levels close to 0, they grow garden crops: tomatoes, zucchini; shrubs: raspberries and blackberries; trees: quince and apple trees.
- According to litmus indicators. A special test kit is purchased in the store. To conduct the experiment, the soil collected from the site is diluted in water in a ratio of 1: 5. The mixture is allowed to settle. A litmus indicator is immersed in the liquid above the sediment. The color of the paper changes. A special template helps determine the pH level.
- According to the Alyamovsky device. It contains various reagents that help analyze 2 soil extracts. Use salt and water extract. The kit also includes an indicator, cones, potassium chloride and examples. The procedure is similar to the previous method.
- According to a universal device. Upon contact with the ground, the device analyzes several indicators: acidity, light level, temperature and humidity.
- Folk way. Currant or cherry leaves are brewed and cooled, soil is placed in the liquid in a ratio of 1:20. The color of the decoction changing to red indicates an acidic environment.
- Fertilizers. The use of mineral fertilizers quickly levels out the acid balance in the area. Ammonium, potassium chloride, superphosphates, and calcium nitrate are suitable for this. Substances contribute to the retention of cations in the soil, due to which alkalization occurs.
- Lime. The purchased lime flour is added to the soil at a depth of 20 cm. The dosage depends on the degree of acidity. The lower the pH level, the more substances are added. Lime removes aluminum and hydrogen from upper layers soil, replaces them with calcium and magnesium.
- Green manure. To improve the properties of the soil, any of the green manures are planted 2–3 times a year: oats, phacelia, rye, legumes. Sowing is done over 3–4 years to achieve maximum efficiency method.
Having determined the properties of the soil on the site, they begin to select plants or change soil parameters.
What to do if the soil is acidic
Unadapted plants in an acidic environment become sick and wither. This occurs due to the fact that nutrients are not absorbed or are converted into a different form. For example, aluminum and iron turn into salts, which prevent the penetration of molybdenum, magnesium and phosphorus into the culture tissue. If the plant does not die, then the yield will be low.
Substances to combat soil acidity:
Simple methods of reducing acidity will help make the site fertile in a short time.
Soil analysis is carried out once every 2–3 years. This helps to carry out timely procedures to improve the quality of the land on the site.
A large number of gardeners face certain problems when caring for certain plants. Such problems are faced by those gardeners who begin to grow heather or fern crops. The fact is that these families require a certain amount of personal care if you wanted to see how your plant will grow and develop.
Also, fastidious plants include flowers such as lilies, hydrangeas, lupins and so on. The main mistake when caring for such plants is inattention to the soil in which the flower grows; the fact is that all plants require a certain level of acidity. For such fastidious plants, which we talked about earlier, you need the most high level acidity of the soil, otherwise they may begin to fade. When caring for such plants, it is necessary to measure the pH level; it should be at level 4 or lower.
Probably many gardeners have encountered the problem of acidity in the soil, but a large number of people fought to lower it. All this lies in the fact that almost all vegetables, berries, fruitful trees and other greens require a weak pH level or neutral. In some cases, even alkaline soil is required.
And when gardeners are going to grow heather families or other similar plants, such crops require a certain level of acidity in the soil. Before you start acidifying the soil, you need to find out what kind of soil you have in order to choose the best possible soil for your plant.
There are several options for determining the acidity level of your soil:
Laboratory method
The first level of determination can be attributed to laboratory methods. If you want to get accurate data on your pH level and will not spare some money for it. Then you need to contact special laboratories.
These laboratories are called soil science laboratories. Specialists will take required samples from your site, with the help of this material they will be able to conduct a multifaceted study and give you accurate results acidity level throughout the land plot.
At home
The second option is to determine the acidity level at home. But using this method you will not be able to determine the exact acidity level of your soil. This method will help you save money and roughly determine your acidity level. In order to determine the level, you need to do the following:
Litmus paper method
You will need litmus paper and a soil solution. The solution should be settled and well mixed. To determine the acidity level, you need to dip litmus paper into this solution and watch how the paper changes color.
If the paper has a blue tint, then the soil is alkaline. If a red color begins to appear on the paper, then your soil is at a predominant acid level. If a yellow-green tint appears on the table paper, then we can safely say that in your soil the two environments are equal and the soil is a neutral environment for plants.
You can also roughly determine the level of acidity and alkalinity, then you should look at the contrast of the color that appears on litmus paper. For example, the brighter the red color, the higher the acidity level of your soil. Also with alkaline pH.
Using specialized tests
For the next method, we will need special tests, which can be purchased at many gardening stores. This method is the most accurate of all home tests. You can find out everything you need to carry out the test in the test instructions.
Method from scrap materials
The last method, but no less effective. To carry out the test, we don’t have to do anything complicated, nor do we have to buy anything. Since almost everyone has all the necessary things in their home. For the test we need soda and acetic acid.
This method will not cause you any difficulties. To determine the environment, you will also need to take some soil from your site. Divide it into two parts, pour a little vinegar into one of them, and add a pinch of soda to the other and watch the reaction. If the soil into which you poured vinegar begins to bubble and hiss, it means that an alkaline environment prevails in the soil. Also, if the reaction begins to appear in contact with soda, it means that an acidic environment predominates in the earth.
Determine the pH level of water
If you do not want to do any research, then this method is suitable for you. To do this, you need to find out what the pH level of your water is. You don't need anything for this. Well, besides, what kind of water do you water your land with?
If you water the ground piped water, then most likely your soil is alkaline. Since the pipeline uses alkali to disinfect water. In this case, your soil needs to increase its acidity level a little.
It is best to water the soil with filtered water, since after such water your soil will be as close as possible to a neutral environment. But this watering method is considered very expensive, since it will be necessary to water a large number of plants and this will require a lot of filtered water.
For those who are not particularly versed in the pH indicator, we will now tell you a little. The pH level ranges from 0 to 14 points. The higher the pH level, the more alkaline the environment. Also in reverse order. For example and better understanding, acetic acid has a pH of 0, and household products have a pH of 14.
How to increase soil acidity
Before you start oxidizing the soil in your garden, you need to find out its mechanical composition. The composition of the soil will directly determine the method that will need to be used to increase acidity.
The first method is perfect for fairly loose soil. In this case the best way will add large amounts of organic matter to the soil. The best organic remedies would be compost, manure or sphagnum moss. As the humus process takes place, the pH level in your soil will begin to drop significantly to make the process more efficient and noticeable. A large amount of organic matter will be needed.
The second method is only suitable for dense and heavy soil, such soil is generally called clayey. In this case, you will need a lot of time and much more effort to increase acidity. If you decide to use the first option with such soil, then nothing good should be expected. Since with the help organic compounds you will only increase the alkaline level of the soil.
- One way you can increase soil acidity is by adding sulfur to the clay rock. Over time, the soil's clayey environment will begin to turn into sulfuric acid. In order to lower the pH from 7 to 4.5. You will need about a kilogram of sulfur for a flowerbed of soil measuring three by three meters. Earlier we said that the process of increasing acidity takes a long time, in this method it manifests itself in the best possible way. Since the effect of this manipulation will be visible only after a year.
- IN following method we need ferrous sulfate. Also this method is the fastest that is possible with clay soil. For this method you will need one kilogram of iron sulfate per 15 square meters of land. With this method, results will be visible within a few weeks. This speed is due to the fact that this substance is much smaller than sulfur, and the temperature of the environment also affects this.
- The final method is to use urea or other fertilizers, with great content ammonia. The main thing in this method that in no case should you use various mixtures that contain calcium and potassium nitrate.
How to maintain the required acidity level
When you reach the required pH level, you should not immediately relax, since only half of the difficult path has been completed. In order for your plants to begin to grow properly, you need to maintain this level acidity. Since minor deviations from the required pH level require emergency measures, otherwise you can say goodbye to your plant.
One of the emergency measures is the use of sulfur, this substance is the most optimal for your plant, since it will not harm it in any way, and it will also gradually lower the pH level so that your plant does not face stressful situations. In order to avoid harming the plant as much as possible, it is necessary to add sulfur only to moist soil and not to touch the roots of the plant.
Natural acidifiers are also excellent, as they do not harm the soil in any way and have a long-lasting effect. Such substances are leaf humus and cotton seed cake.
Under no circumstances should you use acetic acid, it will certainly give a quick and visible effect. But this effect Not only will it not last long, but after acetic acid, all beneficial bacteria and fungi in the soil will die and will not appear again.
The most effective way is the addition of aluminum sulfate to the groundbait layer; this manipulation must be performed once a year. But when you add sulfate, make sure that the plant's roots remain intact.
Some plants such as camellias, lupins, garden lilies and primroses love acidic soils with low pH. If your soil isn't acidic enough or has been heavily limed, read our article on how to increase soil acidity to keep your favorite flowers happy.
Steps
Soil and water acidity testing
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Do the test yourself. If you do not want to contact the services of specialists, then you can easily check the acidity of the soil yourself. But you must understand that your results will not be as accurate as those obtained in the laboratory. Here's how to do the test at home:
- Use litmus strips (test paper) to test acidity. This test will tell you whether your soil is acidic or alkaline, and it can easily test the pH of the soil in which your flowers and vegetables grow.
- You can use vinegar and baking soda to test soil acidity. This is the most primitive method, which consists of adding vinegar and baking soda to the soil separately and seeing what sizzles. If vinegar sizzles, then the soil is alkaline, if it sizzles baking soda- it's sour.
- Buy home set for testing. This set should show you the acidity level of your soil, which gives you an idea about it. more information than simply indicating that your soil is acidic or alkaline.
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Don't forget to also check the pH of the water. The acidity of the water you use to water your plants can range from 6.5 pH to 8.5 pH, but is generally more alkaline to avoid corrosion. water pipes. If you water your plants with alkaline water and your soil is also alkaline, then you will need to acidify the soil.
- One way to get around this potential problem is to use clean, filtered water. Its acidity is 7, which makes it almost completely neutral. Using clean, filtered water will effective means, but after a while it can become expensive.
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Know how to calculate the pH of any test you use. pH is a measure of how alkaline or acidic a test substance is. The measurement scale ranges from 0 to 14, where 0 means the substance is very acidic (battery acid) and 14 means it is very alkaline ( liquid product for cleaning bathtubs and sinks). 7 is considered neutral.
- For example, if the acidity of your soil is 8.5 pH, then this means that it is slightly alkaline. You will need to acidify it. If the soil acidity is 6.5 pH, this means that it is slightly acidic. If you want your soil to be even more acidic, then you will need to add additional acidifying agents.
Soil acidification
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Determine your soil type. It is very important. The type of soil you have will tell you which acidification method you will need to use.
- Well-drained and relatively loose soil will make acidification much easier. This type of soil can be acidified with large amounts of organic compounds.
- Clayey, heavy soil will make acidification much more difficult. Adding organic material to such soil will only make it more alkaline.
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Add organic matter to well-drained, loose soils. To acidify these types of soils, organic matter will best choice. They acidify the soil as they decompose, but large amounts are required to lower the pH. Here are some good organic materials you can use:
- Sphagnum
- Oak leaf compost
- Compost and manure
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Add sulfur to clay and heavy soil. As mentioned above, adding organic matter to very dense soil can make the problem worse, as such soil retains moisture, making it more alkaline. For this reason, the most reliable way to acidify the soil is to add sulfur or iron sulfate to it.
- Sulfur also oxidizes the soil with the help of bacteria that convert the sulfur into sulfuric acid. It takes about a kilogram of sulfur per 9 square meters to reduce the soil pH from 7 pH to 4.5 pH.
- Since sulfur turns into sulfuric acid quite slowly, it will be better if it is added to the soil in advance, about a year before planting.
- Add sulfur to the soil to a depth of 12 cm.
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Add ferrous sulfate to clay and heavy soil. To acidify the soil, iron sulfate requires chemical reaction. Therefore, it depends less than sulfur temperature conditions, since sulfur needs bacteria.
- You may need more than 5kg of ferrous sulfate for every 90 square meters of soil to lower the pH by one unit.
- Ferrous sulfate acts faster than sulfur. It can significantly lower the pH in 2-3 weeks. It gives him additional benefit, so you can use it in the same season you choose to plant.
- Be careful when using ferrous sulfate. He can get dirty rusty spots your clothes, floors, etc. If you stain your clothes with it, wash them separately.
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Use a fertilizer that contains ammonia. In most cases, this is all you need to do to acidify the soil. Many of the fertilizers used for plants that like acidic soils contain ammonia sulfate or sulfur-coated urea.
- Calcium nitrate and potassium nitrate should not be used as fertilizers, even if they contain ammonia. These fertilizers raise the pH of your soil.
Of course, you'll get the most accurate results if you send your soil samples to a professional for testing. We're not comfortable telling you to pay someone a ton of money, but if you're serious about growing plants or really need to acidify your soil, lab results will be more accurate than results obtained at home. The difference in soil acidity between 5.5 pH and 6.5 pH will be quite large!
Increased acidity of the soil solution is a physiological mine of not only delayed, but also long-lasting action. With increasing acidity, the growth and branching of roots, the permeability of root cells deteriorate, and therefore the use of water and soil nutrients by plants and applied fertilizers deteriorates.
In addition to the direct negative impact, increased soil acidity has a multifaceted indirect effect on the plant.
In acidic soils, the activity of beneficial soil microorganisms very depressed. The formation of forms of phosphorus and other nutrients available to plants due to the weakening of the mineralization of organic material is weak. At the same time, increased acidity promotes the development of fungi in the soil, among which there are many parasites and pathogens of various plant diseases. In acidic soils, the mobility of molybdenum decreases, and in sandy soils, the mobility of calcium and magnesium compounds is low. Thus, increased soil acidity reduces its fertility and negatively affects the development of most cultivated plants.
Plants react differently to soil acidity. easily tolerated increased acidity and does not require liming. Tomatoes, carrots, peppers, and radishes grow well in moderate acidity and respond poorly to additional liming. But beets and cabbage need liming. The most sensitive to increased acidity at the beginning of the growing season are cucumbers, beets, onions, garlic, and currants.
The degree of soil acidity is indicated by the pH sign and the corresponding number. The soil can be strongly acidic (pH 3-4), acidic (pH 4.1-4.5), moderately acidic (4.6-5), slightly acidic (pH 5.1-5.5), close to neutral (pH 5 ,6-6.0), neutral (pH 6.1-7.0) and alkaline (pH 7.1-8.0).
Plants grown in garden plots are divided into four groups in relation to soil acidity.
1. Not tolerant of acidic soils and requiring a neutral or slightly alkaline reaction of the soil environment - currants (black, red, white), cabbages of all types, lettuce, celery, onions, spinach, beets, aster, leftover, roses, chrysanthemums, kochia, ageratum .
2. Those in need of a slightly acidic and close to neutral reaction - apple trees, plums, cherries, beans, peas, rutabaga, cucumbers, rose hips, bellflowers, primrose, pelargonium.
3. Tolerating moderate acidity - raspberries, pears, strawberries, gooseberries, turnips, radishes, radishes, carrots, pumpkin, tomatoes.
4. Tolerant of high acidity - sorrel, lupine, hydrangea.
For most vegetables, fruits and berry crops optimal values pH – 5.5-6.5, i.e. the soil should be slightly acidic to almost neutral.
You can accurately determine the acidity of the soil using laboratory analysis, or independently using indicator litmus paper. To do this, dig a vertical hole in the area with a shovel to the depth of the fertile layer, from which a thin layer of soil is taken from top to bottom on the wall and mixed thoroughly. Then a portion of the soil, previously moistened with rainwater, is squeezed in the hand with a strip of indicator paper. When compressed, the released moisture wets the paper. Depending on the acidity of the soil, the paper changes color. If the paper turns red, the soil is very acidic. pink color means medium acidity, yellow means slightly acidic, light blue means close to neutral, blue means neutral.
Acidity can be determined by weeds. It is not for nothing that many weeds are excellent living indicators. If your site is overgrown with sedge, horsetail, wheatgrass, woodlice, heather, then the soil is very acidic. Less acidic soil is preferred by small sorrel, creeping buttercup, plantain, and mint. Field bindweed, odorous chamomile, coltsfoot, quinoa, nettle, thistle, alfalfa, and clover like to settle in cultivated areas with low soil acidity. And one more plant sign: where birch and rowan grow well, the soil is close to neutral in acidity.
With great accuracy, acidity can be determined as follows. Take a small amount of soil from the hole, fill it up to the second division from the bottom into a 200 cm3 bottle (used for feeding infants), and fill it with water up to the fifth division. Then pour half a teaspoon of powdered soap or tooth powder into the bottle and immediately put a coiled baby pacifier on the neck. The nipple unfolds when put on, but due to the lack of pressure it remains stuck together. Then shake the bottle vigorously for 3-5 minutes. If the soil is acidic, then the chalk released when the acid reacts carbon dioxide The pressure inside will increase and the nipple will inflate. If the soil is moderately acidic, the teat will expand halfway. If the soil is slightly acidic or neutral, the nipple will remain in the same condition.
A wide variety of materials are used for liming different materials containing . General content calcium in them is: ground limestone - 75-100%, slaked lime– up to 100%, dolomite flour – 75-100%, cement dust – 30-60%, wood ash– 30-35%. For soils with normal moisture, it is necessary to add the doses of ground limestone indicated in the table (kg/10 m2). For soils with excess moisture, the data given in the table is increased by 10% (table).
Typically, acidic soils are limed once every 5-6 years. However, in amateur gardens it is also possible to annually apply small doses of lime fertilizers to the soil.
It must be taken into account that lime dissolves slowly and interacts with the soil. Its effect manifests itself gradually, so the effect of liming reaches its maximum in the second or third year.
The effectiveness of lime application largely depends on its uniform application and thorough mixing with the soil. Lime must be well crushed and evenly scattered over the soil surface before incorporation. It is necessary to use a method of incorporation of lime that ensures good mixing with the arable layer of soil - it is better when digging the soil with a shovel in the autumn. Spring liming should be carried out no later than 3 weeks before sowing.
Adding excessive doses of lime to the soil is doubly expensive - both financially and it can “alkaline” the soil. It is quite difficult to return such soil to its normal state. We can only recommend adding large doses of acidic, non-composted peat.
K. Preobrazhensky,
Ph.D. agricultural sciences
Newspaper "GARDENER" No. 33, 2011.
11.11.2014 | The soil
Experienced gardeners know that good soil- deposit good harvest. More precisely, not so much good, but rather suitable for the plants and crops that are grown on it. Some things grow well in alkaline soils, some grow well in neutral soils, and some crops only like acidic soil. And then you have to wonder how to acidify the soil? To do this, you will need to change the acidity pH - the lower it is, the more acidic the soil.
Before you start acidifying the soil, you need to determine the initial pH to make sure that this is really necessary. If the above indicator is above 5 units, then acidification cannot be avoided.
Method 1. Lowering soil pH using acid, sulfur and peat
In fact, gardeners are often interested in the question not of how to increase the acidity of the soil, but of how to deacidify the soil, and for this they use a variety of materials, from limestone flour to sowing green manure that promotes deacidification. To acidify the soil, they resort in particular to simple and proven methods, such as watering with acidified water at the rate of 10 liters of solution per square meter. The solution is prepared as follows: use oxalic or citric acid, dilute 1.5 - 2 tablespoons per 10 liters of water. You can also take 9% malic or acetic acid - 10 liters will require 100 grams of vinegar.Effectively acidify the soil personal plot, lowering the pH to 3.5 - 4, you can use sulfur - 70 grams per square meter land. Peat is also suitable - 1.5 kilograms per square meter of soil.
Method 2. Electrolytes for soil acidification
It is best to use battery electrolyte to increase the acidity of the soil, but not a used one, but a new one. This is essentially a diluted sulfuric acid, and as mentioned above, sulfur is something that can help acidify the soil.How to calculate how much electrolyte you need? To do this, it is worth starting from the initial pH of the soil. So if it is 6 units, then the soil is spilled with a solution whose pH will be 2 - 3 units. To do this, take 2 - 3 ml of electrolyte with a density of 1.22 g/cm 2 per liter of water. If the solution has a density of 1.81 g/cm 2, then its required volume will be reduced to 0.5 - 0.7 ml per liter of water.