When and Why to Use Lime to De-acidify Soil?

How is soil liming helpful?

The soil continuously changes its properties under the impact of various factors such as:

• minerals and gases contained in rain drops,
• components contained in natural and artificial fertilisers used by farmers,
• the specific nature of the crops growing in the particular area (some species impoverish the soil faster than others),
• distance to trees (for instance: pine needles or oak leaves falling on the ground acidify the soil).

Our ancestors had discovered that crop rotation alone is not enough to keep the appropriate quality of ground for sowing. So they started to use different types of fertilisers, including fertilizer lime. What does lime do in soil? Adding lime:

• gives the soil the appropriate acidity,
• makes it easier for plants to collect phosphorus from the ground, enabling more stable growth,
• creates soil conditions favourable to micro-organisms, aerating earthworms, etc.

Thanks to liming, the soil is more fertile and richer in mineral substances. A natural supplement is produced, for example, by organic matter being processed by bacteria and fungi, which eagerly inhabit a soil with the optimum pH level.

Which lime for soil de-acidification is the best?

Most farming and gardening stores offer soil de-acidifying lime. It is usually calcium carbonate, that is, the salt of carbonic acid and calcium: a white inorganic compound slightly soluble in water. As a product, it occurs in loose (powdered) and granulated forms (granulates, fertiliser chalks). Calcium fertiliser can also be enriched with magnesium. Some farmers also use stronger agents, such as burnt or slaked lime, in place of calcium carbonate.

Which soil de-acidifying lime is the best? Of course, there is no single answer to this question. The type of lime should be suited to the soil specification: powdered lime will be good for light and high-permeable soils. For heavy and clayey soils, it is better to apply stronger agents: concentrated granulates or burnt lime.

When is it best to lime soil?

Liming can improve the acidity of the soil and contribute to a faster growth of the crops, provided that it is performed in the right moment. Experienced farmers know when the soil should be limed: it is best to do it in late autumn or early spring. Some farmers use calcium carbonate in November, once the harvest is completed. Others apply it in March, a few weeks before the planned sowing.

Powdered lime quickly penetrates into the soil, unlike granules, which dissolve slowly. When to spread granulated lime? Manufacturers recommend using it in the autumn so they gradually release the beneficial compounds to the ground. Liming can be performed once every 1–2 years or less frequently, depending on soil acidity level.

Granulated magnesium lime: when to use it?

When the soil is extremely acidic and lacks magnesium, use lime with magnesium in the form of granules. When to spread granulated magnesium lime? It is an all-season fertiliser that works well in autumn, spring and summer. Use it after analysing your soil samples, if the soil is too acidic and its level of magnesium is too low.

Granulated chalk lime: when to use it?

Chalk lime is one of the most commonly used soil acidity improvers used in agriculture. When to fertilise with this type of lime? We recommend covering the ground with chalk immediately after harvesting. If the soil is highly prone to acidification, you can de-acidify it with lime a few times a year, also before starting working your fields in early spring.