Acidic soils need to reduce acidity, because not all plants grow well in such soil. Liming is one of the mandatory agrotechnical methods for improving soils. Let's consider the types of soils based on acidity, its levels, how it is possible to determine how acidic the soil is, how and how much lime to add, and common mistakes that gardeners can make when liming the soil.
Why do soil liming?
Quicklime is called calcium oxide, but slaked lime, called fluff, is used for liming. Calcium is the main element in the composition, but the mineral may contain magnesium and other elements.
The main purpose of adding lime to the soil is to normalize acidity, but it can also be considered a calcium fertilizer. After liming, not only does the acidity decrease, the soil becomes loose and better absorbs moisture, which is retained in its upper layers. Drying of the soil slows down, moisture enters the roots of the plants. The amount of toxic substances that can accumulate in plants is reduced. Due to the normalization of acidity in the soil, conditions are created for the proliferation of beneficial soil microflora.
Acidity levels
Neutral soil acidity is designated as pH 6.5-7. If the value is less, then it is sour. Soils are considered weakly acidic at a pH of 5-6, moderately acidic at a pH of 4-5, and strongly acidic at a pH of 4 or less. Such soils require deoxidation.
Acidity negatively affects the development of many cultivated plants, makes micronutrients less available to plants, increases the availability of harmful metal compounds, and worsens the physical properties of the soil.
Types of soils by degree of acidity
Podzolic forest, clay-turf, peat and coniferous soils are considered acidic. Strongly acidic - swamp soil and lowland peat, weakly acidic - turf and heather.
Neutral reaction in chernozems, deciduous and humus soils. Carbonate soils are alkaline.
How to determine it?
To determine the acidity of the soil in your area, you can use different methods. Let's take a closer look at them.
Table vinegar
You need to take a lump of earth, scatter it on the film and sprinkle it with vinegar. If nothing happens, then the soil in the garden is acidic and there will be no reaction. If hissing bubbles appear on the surface of the mass, then the reaction is neutral or alkaline. In this case, liming is not required.
Tea made from cherry or currant leaves
Take cherry or currant leaves, pour boiling water and leave to steep for 20 minutes. Add earth to the infusion; if the liquid turns bluish in color, it means the soil is acidic; the liquid turns greenish – neutral or alkaline.
Grape juice
You need to throw soil taken from the garden into a glass of fresh juice. If a color change occurs and bubbles begin to appear, the soil may be acidic.
Soda
First you need to mix the soil with water to form a liquid mass. Sprinkle soda on it. Hissing and bubbling will indicate an acidic reaction.
Other methods
You can also tell if the soil on a site is acidic by looking at the weeds that grow on it. The following grow on sour soil: horse sorrel, horsetail, heather, moss, mint, sedge, lupine, cinquefoil, plantain, bentgrass, knotweed, mustard, woodlice, and buttercup. In areas with a reaction closer to neutral you can find: nettle, wheatgrass, bindweed, chamomile, coltsfoot, thistle, quinoa, radish, fescue, clover, cornflower, soapwort, china. Chestweed, wild poppy, and larkspur appear on alkaline ones.
How to properly apply lime to the soil
The best time for liming is in the fall, when preparing the site for winter, when plant debris is being removed and digging is underway. If for some reason it was not possible to do this at the end of the season, you can lime in the spring, but no later than 3 weeks before sowing seeds or planting seedlings.
To calculate how much lime is needed, you need to determine not only the cultivated area, but also other factors: mechanical composition, natural acidity, acidity requirements of the crops that will be grown in the beds after liming.
Approximate application rate for different types of soil (in g per sq. m.):
- for strongly acidic ones - from 250 on peat bogs and up to 900 for clayey ones:
- for medium acid – from 100 to 650;
- for slightly acidic ones – 50 to 500.
Full dose liming is not carried out every year, but once every 4-5 years. More frequent use of lime will not bring benefit, but harm, due to a decrease in the availability of boron and copper, and a large amount of potassium. Another acidity test should be carried out after the soil has been treated with lime. It is necessary that it show a neutral or slightly acidic reaction, which is also acceptable. The test must be carried out every year and, if it turns out that the acidity is increasing, it must be neutralized with small portions of lime. It should be in powder form, the finer the better. Distribute the powder evenly over the beds and be sure to dig up and loosen the soil afterwards. The digging depth for the main application is 20-25 cm, for partial application - 10 cm.
Common mistakes
Do not use fresh quicklime, which is caustic and can cause burns. You need to purchase slaked fluffed lime or quench quicklime before use.
Lime cannot be combined with fertilizers; you must first deoxidize the soil and then add fertilizers.The interval between applications should be at least 2 weeks. When applied together, lime and fertilizers can react, forming compounds that are harmful to plants. Since lime contains a lot of calcium, after applying it it is necessary to adjust the amount of fertilizers, especially those containing this element, so that there is no excess of it in the soil.
If you do not use safety precautions when working with lime, you can get skin irritation or burns. It is necessary to wear rubber gloves and a respirator, which will protect the skin and respiratory tract from the powder.
Liming the soil on your site must be carried out if it is highly acidified. In such land it will not be possible to get a good harvest, because conditions for the normal functioning of crops have not been created. This is a simple agrotechnical technique that is carried out rarely - once every few years. Lime can be bought at any hardware store; in a dry place it is stored for a long time, you can use it for several years in a row. Its application normalizes acidity, feeds plants with calcium, magnesium and other microelements, prevents the penetration of heavy metals and nitrates into them, that is, it makes vegetable and fruit products of better quality.
