How to lime soil in the fall: necessity, pros and cons, lime fertilizers

If your soil is too acidic, liming can help. This procedure not only reduces acidity but also enriches the soil with nutrients such as magnesium (Mg), calcium (Ca), phosphorus (P), and nitrogen (N). After applying lime, the soil becomes looser and retains moisture better. Let's look at how to apply lime correctly and when it's essential.

The need for liming

Soils with pH values ​​below 5.5 require liming, as many crops simply cannot grow and thrive in acidic soils. Tomatoes and legumes are considered the most sensitive garden crops. Improving the soil structure will improve the absorption of nutrients by plants. A deficiency of calcium and magnesium in the soil can lead to:

• reduces its air permeability;
• promotes compaction of the upper layers of soil and crust formation;
• increases the viscosity of the substrate;
• increases the amount of toxic substances for garden crops;

As a result, the soil loses beneficial microorganisms and earthworms, whose activity improves the structure and composition of the substrate. High acidity slows plant growth because they are unable to absorb nutrients.

Advantages and disadvantages of autumn soil liming

Lime is applied to the soil both in the fall and in the spring. However, lime is most often applied in the fall, during tillage. The advantage of this method is that nitrogen-based fertilizers containing ammonium are used during the growing season, and any fertilizers containing ammonium cannot be used together with lime. It is also recommended that lime be applied no later than 21 days before planting seedlings or sowing seeds.

The downsides of liming in the fall include the fact that certain soil deoxidizers cannot be used simultaneously with organic matter, which is added during tillage. Also, the procedure is recommended to be carried out in dry weather, as rain is common in the fall.

What substances are used for liming?

Fruit yield and flavor largely depend on normal soil pH. High pH levels can interfere with plant nutrient absorption, resulting in stunted crop development and a lack of fruiting. To deacidify the soil, neutralizing agents are used, including:

• lime;
• dolomite flour;
• wood ash;
• peat tuff;
• blast furnace slag;
• waste remaining during sugar production;
• construction dust;

Optimal acidity and types of liming

Before liming the soil, you need to determine what crops will be growing in the area. This procedure can either improve or detract from the plant's growth and development. Every plant is unique; some prefer acidic soil, others slightly acidic, and still others neutral. Cruciferous vegetables and beets don't tolerate high acidity, while lupines and tea thrive in acidic soil. Cucumbers, tomatoes, onions, and legumes prefer neutral soil.

Liming is divided into two types:

• main;
• supportive;

The main treatment is performed only once, and the maintenance treatment is performed every 3-5 years. This procedure is carried out in spring or fall, but fall is more suitable. The required amount of lime is distributed over the entire area, potassium or magnesium-based fertilizers are added, and the soil is dug. The digging depth should be 15 to 20 centimeters. If the soil is not dug, the effectiveness of the procedure is reduced. In spring, the liming material is applied one month before application. fertilizersIt is also evenly scattered over the soil surface, and then surface digging is carried out.

Why does soil acidity increase?

Soil acidity is a measurement of the balance of hydrogen ions in the soil. It is measured on a scale ranging from 1 to 14. Neutral soils have a pH of 7, alkaline soils have a pH of <7, and acidic soils have a pH of >7.

The following can provoke a decrease in acidity:

• excessive watering or heavy rainfall, this is explained by the fact that water washes salt into the deep layers of soil, in addition, the water itself may have a high acid content;
• using compost, peat or fresh manure as fertilizers;
• cultivation and incorporation of green manure crops into the soil, for example, mustard, oats, rapeseed;
• regular use of chemical fertilizers based on ammonium and potassium sulfate;

How to determine the pH level in your soil yourself

Certain weeds often thrive in acidic soils, including grasshoppers, horsetail, sorrel, and creeping buttercup. If you notice a large number of these in your garden, the pH is definitely elevated. A whitish layer on the topsoil is also an indication that the soil is acidic.

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Litmus paper can help determine acidity; it's often used as a pH indicator. While you shouldn't expect precise results, it can help determine whether the soil is acidic. Some gardeners use folk methods, such as vinegar, chalk, or cherry leaves, but an accurate result isn't guaranteed. You can also purchase a special electronic indicator with a probe; it's quite easy to use. For more detailed soil analysis, send the soil to a laboratory for testing.

What kind of lime is added to the soil?

To achieve a positive result, lime must be thoroughly mixed with the soil. For this reason, it's best to use lime in powder form. Quicklime is lumpy, and if used in this state, it can oversaturate the soil. Therefore, before applying, it's slaked (20 liters of water per 50 kg of soil), and then poured into the lime. After stirring, the water will be absorbed, and the lime will become powdery and ready for use.

Acid and alkali in the soil

Acidity is formed by H+ ions, which are more common in elements on the right side of the periodic table. Alkaline compounds are formed by OH- ions, usually metals, which are located closer to the left edge. Elements located between them are called amphoteric. They can form both alkalis and acids. Acids include:

• sulfuric;
• vinegar;
• salt;
• nitrogen;
• hydrocyanic;

Aluminum can form an alkali in some cases, but on an industrial scale, salts are most often used where it is part of the acid residue. These are called aluminates.

Hydrogen index

Under all conditions, a water-soluble substance should dissociate into ions. However, in practice, things are a bit more complicated. Most salts based on alkali and alkaline earth metals, as well as some acids, dissociate upon contact with water. However, acetic acid, hydrocyanic acid, silicic acid, and iron hydroxide are exceptions to the rule. Therefore, the acidity of a medium also depends on the substance's ability to dissociate into ions.

Water is a neutral medium; the amount of H+ in it is equal to the amount of OH-. Thus, the content of each is equal to 10-7 mol/liter. 7 is the neutral value, and the upper number is the hydrogen content.

Ionic balance

It's important to note that not every environment needs to be neutral. The habitats that support some organisms are harmful to others. Marine life and microorganisms thrive in alkaline environments, with a pH of 8, while swamps, on the other hand, have highly acidic soil.

Methods of compensation

Alkali and earth metals form hydrogen and salt when reacted with acid. However, at high concentrations of these substances, other reactions occur. For example, sodium, when mixed with large amounts of nitrogen, forms sodium nitrate and ammonium nitrate. Alkaline earth metals include barium, magnesium, calcium, and radium, while alkali metals include sodium, lithium, francium, and potassium. However, they do not exist in nature in pure form.

To maintain a healthy soil balance, periodically add wood ash and mulch. These procedures will protect the soil from natural elements and restore sodium, potassium, and calcium levels. However, the primary way to compensate for soil acidity is liming, which is best done in the fall. Fertilizers should be applied in the spring, and using them simultaneously with lime is not recommended.

Dosage of lime materials depending on soil acidity

Before liming the soil in the fall, it's important to study the application rates for different substances. Limestones can vary in concentration, and an excess of the substance can also negatively impact plant growth.

Slaked lime (fluff)

If the pH is less than 4, 5-6 kg of the substance will be needed per 10 square meters. For higher acidity, 4-5 kg ​​per 10 square meters will be sufficient. For soils with a pH of 4 to 5, 3-4 kg per 10 square meters is required. For slightly acidic soils, 2-3 kg of lime per 10 square meters is sufficient.

As for other substances, the lime content in them is slightly different. The required proportion can be calculated using the following algorithm:

1. First, you need to find out the norm of lime for the soil.
2. Multiply the indicator by one hundred.
3. Divide the obtained result by the percentage of lime content in the substance.

The ratio of lime in substances in percentage

If you can't measure soil acidity, you can do without it. For clay soils, apply 6-7 kg of lime per 10 square meters, for loam soils, apply 5 kg per 10 square meters, and for sandy soils, 3 kg of the substance is sufficient.

Soil cultivation in a greenhouse

Many gardeners grow vegetables in greenhouses but don't understand why and when to lime the soil. Even high-quality soil with a neutral pH can become acidic. This is unacceptable for some vegetables; they will simply stop producing crops, even with fertilizer. Long-term cultivation exposes the soil to water, which can become highly acidic, and some fertilizers can also increase pH.

If the soil is highly acidic, plants will be unable to absorb potassium and magnesium from the soil and will grow poorly. To ensure a stable harvest, liming is necessary periodically, with autumn considered the best time. Dolomite flour is most often used indoors. It not only deacidifies the soil but also contains the necessary elements for normal crop development. The procedure itself is no different from liming open ground. The main thing is to follow the application rates.

Conclusion

Soil condition is a crucial component of achieving a good harvest. The optimal pH balance varies for each crop. Most plants prefer neutral soils, so regular liming is essential. The procedure itself doesn't take much time, but it's important to calculate the appropriate dosage beforehand.