Key Considerations

Several needs should be taken into consideration when selecting the right product before you plant your next crop:

  • Acidic soils (low pH)
  • Impaired root growth 
  • Low levels of calcium and magnesium nutrients
  • Poor soil drainage
  • Low crop yield

Your Benefits

  • Promotes higher crop yields
  • Promotes healthy root systems
  • Improves nutritional value of soil
  • Enhances fertilizer/herbicide efficiency

Calcitic Lime: Product Description

Crop yield is heavily dependent on soil health. It is a simple equation. The better the growing conditions a soil provides, the more productive your fields will be. However, over time, even healthy soils will deteriorate, as soil acidity increases. Soil acidification is a natural process, but can be accelerated by practices used to improve crop productivity, particularly the application of manure and use of nitrogen fertilizers. It is also a critical challenge as acidic soils produce noticeably lower yields.

Another challenge is posed by the soil composition, for example soil compaction. Heavily compacted soils make it difficult for plants to grow healthy root systems. Without healthy roots, plant growth is stunted — which again results in lower yields. There are many other factors to soil health, including soil pH balance, magnesium levels (either excess magnesium or a magnesium deficiency), sandy soil, and more. Any one of these factors can hinder plant health and crop growth, leading to a reduction in the availability of valuable nutrients.

Fortunately, even the poorest soil can become healthy soil once again with the addition of calcitic lime, such as High-Calcium Ag Lime from Carmeuse. Calcitic lime is a type of agricultural lime product derived from limestone that is almost pure calcium carbonate (calcite, CaCO3). Calcitic lime contrasts with dolomitic lime. Dolomitic lime comes from limestone that contains both calcite and magnesium carbonate (dolomite, MgCO3). The ratios of calcite and magnesium carbonate found in dolomitic lime are not always the exact same. Both calcitic lime and dolomitic lime can be supplied as pulverized lime (powdered lime) or pelletized lime for spreading. Both the pulverized lime and the pelletized lime are helpful for treating soil that is magnesium deficient.

How Does Calcitic Lime Work?

The application of calcium carbonate to soils helps counter both the problem of soil acidity and that of heavily compacted soils.

As a naturally alkaline (base) material, calcium carbonate is a safe and effective means of rebalancing soil acidity. To dive into some chemistry for a moment, this agricultural lime does so by releasing basic calcium cations (Ca++) into the soil, which replace acidic hydrogen cations (H+), thereby raising the alkalinity of the soil. A soil test can be performed both before the addition of calcitic lime, and after the addition of calcitic lime, and the results will speak for themselves.

Meanwhile, the addition of dolomitic and calcitic limestone products to amend plastic (clay) soils results in a more friable soil. Calcitic lime allows for a reduction in plants with shorter root systems that can often produce noticeably lower yields. At the same time, calcitic lime improves soil drainage and helps to avoid the risk of waterlogging.

The Benefits Of Calcitic Lime

The headline benefit of calcitic lime is higher crop yields. But how exactly does this calcium carbonate material achieve this?

Promotes Healthy Root Systems

Generally speaking, both soil acidity and soil compactness constrain root growth and therefore overall plant growth. By rebalancing the soil pH and/or producing a looser soil, agricultural lime products support the development of healthier root systems, particularly important when plants are younger and more vulnerable. Healthier roots improve the plant’s capacity to absorb nutrients, resulting in a stronger — and more productive — crop.

Rebalancing the soil pH with pulverized limestone also provides a more conducive environment for bacterial growth, which is particularly important when growing leguminous crops, such as alfalfa and peas. These rely on colonies of bacteria that live within their root systems to convert atmospheric nitrogen into the nitrates needed by plants to grow (a process known as nitrogen fixation). These bacteria, called rhizobia, are therefore essential to healthy and productive legume growth, but require a balanced soil pH to thrive.

Improves Nutritional Value Of Soil

The most obvious benefit to the nutritional value of your soil gained by spreading calcitic lime on your field is the replenishment of vital calcium nutrients required by plants as they grow. Agricultural limes — even high-calcium limes — will also contain a percentage of magnesium (either as magnesium carbonate or magnesium oxide), which again helps to replenish magnesium deficient soils.

Staying with magnesium levels for a moment, fields with too much magnesium may find a calcitic lime with very low magnesium levels the most appropriate option. Conversely, soils that are magnesium deficient may require a dolomitic lime product. A soil test can be performed to check magnesium levels at all stages of the process.

The availability of other nutrients also depends on soil acidity. Phosphorus, for example, becomes less available to plants with rising acidity. Aluminum, on the other, becomes more readily absorbed to the point it can become toxic.

And as with the rhizobia colonies so vital to legumes, the rebalancing of soil pH promotes microbial activity more generally. This facilitates the decomposition of organic matter in the soil, releasing the key nutrients found within and making them available to support crop growth.

Enhances Fertilizer/Herbicide Efficiency

Soil acidity also retards the efficiency of fertilizers and herbicides; higher soil pH therefore optimize the impact of both. This brings obvious advantages in terms of plant growth and health, which are enhanced by the judicious application of these products.

But it also has an economic and environmental benefit. By rebalancing soil acidity, agricultural lime creates soil conditions in which the effectiveness of fertilizers and herbicides is optimized. As a result, lower quantities of these chemicals are needed to achieve the desired impact. This not only reduces costs, but also reduces the risk of overuse and toxic soil run-off into surrounding bodies of water.

How Long Does It Take Calcitic Lime To Work?

The short answer is — it depends.

Reactivity time will be influenced by soil conditions and the characteristics of the lime itself:

  • Soil moisture — since the reaction between lime and soil requires water, applications in dryer soils will experience slower reaction times than those in damper conditions.
  • Lime particle size — finer liming materials will react more quickly than coarser lime (a function of their greater surface areas).
  • Method of application — lime that is spread on the surface of the soil will react more slowly than lime that is tilled into the soil.

Generally speaking, even with faster-reacting lime in ideal soil conditions, it will take a number of months to see a measurable change in the soil. For this reason, it is important to apply agricultural lime well in advance of the next growing season in order to get the most of its benefits. We recommend at least two to three months before planting.

How Much Calcitic Lime Do I Need?

Again — it depends!

Low pH soils will require more lime to rebalance than soils that are more neutral. Different crops also require different pH soils (and so different applications of lime). Blueberries actually thrive in slightly acidic soils (about pH 4.5). Recommended soil pH for grasses, corn and oats is 5.8 and 6.2; for wheat and barley, 6.3 to 6.5; and for alfalfa, 6.6 to 7.0.

To effectively determine how much lime is needed, regular soil testing is recommended. This involves taking a soil sample and submitting it for analysis at a laboratory. A number of universities offer testing services, including Cornell University, Penn State University, Michigan State University and Virginia Tech. The US Department of Agriculture also offers guidance on soil testing.

In addition, the amount of lime needed will also depend on the chemical composition of your liming material. You will need less of a high-quality calcitic lime, such as Carmeuse Hi-Calcium Ag Lime, as this has a higher neutralizing power per ton (as measured by its calcium carbonate equivalent, CCE) than lower-quality liming materials.

Going Deeper On Calcitic Lime For Soil Amendment

At Carmeuse, we recognize the value of soil as the foundation of agricultural productivity. For a more detailed look at agricultural lime and its key role in maintaining healthy soil, check out our article on the importance of agricultural lime. You can also check out what we offer in terms of High Calcium Ag Lime for soil beneficiation from a range of locations in North America.

Our agricultural lime products are backed by our team of experts based out of the Carmeuse Innovation Center in Pittsburgh. They are always ready to discuss your needs and help determine what ag lime is right for you. We are focused on providing the right product to achieve your goals, when and where you need it — so you never have to worry. Contact us to find out more about how we can support your specific application.