As our agriculture industry faces the challenge of producing more food to feed a growing population, the risk of soil degradation and the need for environmental sustainability become critical topics.
Going back to our roots: sustainable farming with natural minerals
Jason Imes | Omya Kansas
For more than 2,000 years, farmers have been diligent stewards of the land, understanding the importance of sustainable agriculture for future crops and generations. The role of calcium carbonate in improving fertility, soil structure and soil health was recorded as early as the first century BCE, when the Greek naturalist and philosopher Marcus Terentius Varro wrote in his agricultural textbook ‘De Re Rustica’ of farmers applying chalk to their land.
As our agriculture industry faces the challenge of producing more food to feed a growing population, the risk of soil degradation and the need for environmental sustainability become critical topics. One area where farmers and agronomists are focusing more attention is the use of natural minerals to support sustainable farming practices.
Dr Katharina Koetting, Director Innovation & Technical Marketing Agriculture, at Omya explains the importance of focusing on sustainability: “As global population continues to grow, the demand for food increases, yet at the same time there is pressure to reduce the impact of farming on the environment. Fortunately, the lessons learned all those years ago by the ancient Greeks still apply today. Natural minerals such as limestone, chalk and dolomite contribute significantly to sustainability, not just in terms of soil health, but also the efficient use of resources and a reduction in emissions.”
The importance of healthy soils
Healthy soil is the foundation of sustainable agriculture. It supports plant growth, stores water and nutrients, sequesters carbon and provides a suitable environment for living organisms. However, many years of intensive agriculture have taken their toll, with tillage, fertilizers and compaction contributing to soil degradation. The United Nations estimates that 40% of global soils show persistent declining trends in productivity with up to 12 million hectares of agricultural soils lost every year.
Dr Koetting says restoring and maintaining soil health is crucial for the future of sustainable food production. “We measure soil health in terms of physical, chemical and biological properties. If any of these are deficient, then the soil will be less fertile and productive. The addition of calcium carbonate can have a positive impact on all three aspects of soil health, from improving soil structure through better flocculation, to increasing nutrient availability by raising pH, to optimizing the environment for soil microorganisms that break down organic matter.”
Calcium Carbonate: A Natural Soil Amendment
Calcium carbonate is a naturally occurring mineral typically found in the form of limestone, chalk or marble. One of its key functions in agriculture is to neutralize soil acidity, which is a common problem in many parts of the world and has a detrimental impact on all aspects of soil health as well as on crop production.
“Soil is regarded as acidic when the pH falls below 6.0,” says Dr Koetting. “It’s worth remembering that pH is a logarithmic measure, which means that a pH of 5.0 is ten times as acidic as pH of 6.0. Once the soil becomes acidic, nutrients become less available to the plant, leading to poor crop growth and loss of valuable fertilizers to leaching, run-off and volatilization. Microbial activity is also affected by acidity, reducing the breakdown of organic matter and limiting nutrient release.”
Improving soil structure and fertility
Beyond pH correction, the calcium in calcium carbonate helps improve soil structure through better flocculation and aggregation of soil particles. Dr Koetting elaborates, “The calcium ions bind the soil particles together, which improves soil porosity, drainage, aeration and water holding capacity, as well as helping soil resist compaction. This is particularly important in clay soils which are often dense and poorly aerated. We want soils to have a crumbly texture that allows better water filtration, root penetration and therefore crop establishment.”
Adding calcium carbonate also influences soil microbial activity, which is essential for breaking down organic matter, cycling nutrients, and supporting plant health. Dr Koetting explains, “Soil microbes are most efficient at neutral pH, and in acidic soils their activity is significantly reduced, leading to poor nutrient cycling and lower soil fertility. If we can create a more balanced soil environment, then the beneficial microorganisms will be more abundant and more active, enabling faster decomposition of organic matter and the release of nutrients needed by the crop.”
Reducing the environmental impact of agriculture
In addition to its soil health benefits, the use of calcium carbonate in agriculture can help reduce the environmental impact of farming. Dr Koetting points out that whilst it is widely accepted that inorganic fertilizers are essential to achieve high yields, if those fertilizers are not successfully taken up by the crop, then there is a high level of waste as well as the potential for environmental damage from nutrient leaching run-off and volatilization. “At neutral pH, 100% of applied fertilizers become available to the plant. At a soil pH of 5 only 53% of nitrogen, 31% of phosphorus and 52% of potassium are effectively used by the plant, the rest is potentially lost through leaching or run-off.
Correcting the soil pH makes a significant difference to farmers’ efficient use of inputs and consequent reduction in fertilizer costs.” It's not just fertilizer use efficiency that is positively affected by the addition of calcium carbonate. Better soil structure improves the soil’s ability to retain water, improve drainage and reduce waterlogging. Crops grown in healthy soil have better root systems, enabling the roots to access water and nutrients more easily.
Soil health management promotes carbon sequestration, mitigating greenhouse gas emissions and contributing to climate change mitigation efforts. Studies show that increasing soil pH by liming resulted in significant reduction of N2O emissions and increased crop productivity.
Dr Koetting concludes, “The regular application of calcium carbonate as a soil conditioner has a clear and positive influence on sustainability. Farmers around the world are tasked with supplying increasing volumes of food while reducing their environmental impact. Omya Calciprill and other products made from our natural minerals offer effective solutions that improve soil health and enhance the sustainability of farming practices. By neutralizing soil acidity, improving soil structure and promoting microbial activity, calcium carbonate improves soil health, supports crop productivity and reduces the environmental impact of agriculture. It may be a traditional solution to an age-old problem, but it has worked for over two thousand years and it’s still working now. The difference is we now have technologies to micronize the raw mineral and produce innovative granulated products that deliver results more quickly and are much easier for farmers to use. Adding products such as Omya Calciprill, made from micronized Calcium Carbonate which reacts quickly in the soil, and can efficiently optimize soil pH with a corresponding improvement in soil health and crop productivity.”
For more information about Omya Calciprill and its impact on sustainable agriculture, click here.
The content & opinions in this article are the author’s and do not necessarily represent the views of AgriTechTomorrow
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