Soil is an ecosystem of its own. Teeming with nematodes, bacteria and other microorganisms, it’s more than just the foundation on which farmers grow crops — it’s a hidden world in plain sight and an indicator of ecological health.

Like a digestive system, soil needs the right balance of acidity and alkalinity to perform best, and that’s where lime comes in. Unlike its tropical namesake, the mineral known as lime is alkaline. It increases the soil’s pH and nourishes many plant species. Therefore, there are several beneficial applications of lime for small-scale farms in Africa and the Middle East.

What Is Lime?

Lime is a mineral soil additive made from calcium carbonate. It looks like white lumps or fine, ivory powder. There are two categories of lime: Agricultural lime — which is the form that’s most frequently used — and dolomitic lime, which is mixed into soil that has a magnesium deficiency.

The most common type of agricultural lime is ground limestone, but it can also come from chalk. After limestone is extracted from a mine or quarry, it is crushed to form lime.

How Does Lime Affect Plants?

Most plants prefer a soil pH — a measure of acidity — between 6.2 and 6.8, which means they like slightly acidic or close-to-neutral soil. Although a few plant species, such as blueberries and potatoes, grow well in very acidic soils, most do not.

In areas where the soil is acidic, the minerals and nutrients plants need are less common. Plants growing in this type of soil often struggle to grow and will produce a smaller harvest. To remedy this situation, farmers can apply lime to their land and follow it up by fertilizing their crops.

Applying lime increases the soil’s pH. This makes it more alkaline — another word for basic — which is the opposite of acidic. How does this benefit plants? Plants growing in soil with the right pH develop healthier roots. This might make it easier for them to endure droughts and heavy rain.

Lime improves the nitrogen fixation of some legumes — creating higher legume crop yields — and it provides needed minerals such as calcium and magnesium. It makes it easier for plants to absorb the nutrients they need and it can displace aluminum from the soil, making it more hospitable for plants.

Lime also creates the perfect environment for certain microbes, which benefit plants, to survive. Plants need a mix of bacteria, fungi, and other microorganisms in the soil to stay healthy.

What Are Its Applications for Small-Scale Farms?

Plowing the soil disturbs the natural processes where organic nutrients and other elements are exchanged within the soil. This can make it more acidic. Other causes of high soil acidity are heavy rain, high crop yields, the wrong fertilizer or too much of it, the types of crops planted and the geographic region.

Because of its effects on plants, the benefits of using lime on small-scale farms are such that:

• Certain herbicides will work better.
• Certain fertilizers will work better.
• Plants will yield more crops — increasing profits and reducing food insecurity.
• Extra crops can be used as livestock feed, promoting healthier animals.
• Farmers can escape the poverty cycle.

Liming the soil has long-term benefits. A single application of lime can change the pH of the soil for years to come. Crops that perform well in limed soil include corn, onions, garlic, peas and many more.

What Are the Barriers to Liming?

In remote areas without paved roads, getting a shipment of lime to a farm can be difficult. People often have to carry it in by hand or on a wheelbarrow as a result.

Transporting goods to remote areas is also more expensive than delivering them to a farm just outside the city, so farmers may face higher costs the farther they live from a limestone mine or quarry. This can pose a socioeconomic barrier to liming.

To offset the expense and hassle of carrying limestone by hand after shipping it from hundreds of miles away, farmers should purchase the highest-quality lime they can find so they don’t need to lime their fields often.

A Multipurpose Mineral

Lime benefits crops by increasing root growth, allowing them to absorb more nutrients and maximizing harvests. It can displace aluminum from the soil and create biodiverse soil conditions that help plants thrive. Farmers in Africa and the Middle East, where soil conditions are often acidic, may benefit enormously from applying lime on their property.