As a major by-product of our industry, slag has long been sold by steelmakers for use in construction, but its use in agriculture is been less well known.
In Ukraine, we have been researching its value to farmers to improve soil properties and crop yield.
One of the main reasons why farmers need fertiliser is to reduce the amount of acidity in the soil.
It might seem counter-intuitive, but steel slag has exactly the right chemical composition to do this. Slag has been used in agriculture for some time, notably in the USA, Germany, and France, and it has proved both effective and cost-efficient. Now, technicians at our Kryvyi Rih site in Ukraine have been exploring new ways to sell slag as a fertiliser or soil improver.
The first thing we needed to do was to build a good understanding of what properties farmers are looking for. This enabled us to ensure that the slag we deliver has the best possible combination of minerals, such as calcium oxide, phosphate, magnesium and sulphur – these trace elements support plant growth.
An external research study in Ukraine in 2015 looked at field trials using slag. It showed that corn, beetroot, barley and sunflowers harvests were 230% higher. Importantly, the study also demonstrated that slag represents no threat to the natural fauna and flora.
“More widespread use of steelmaking slag in agricultural applications will allow society to solve several important issues at once,” explains Evgeniy Shidlovskiy, chief technical officer at ArcelorMittal Kryvyi Rih. “It will allow us to eliminate substantial steelmaking wastes, and will allow farmers to optimise the pH levels in their soil, cut costs and improve their harvests.”
Given the importance of agriculture to the Ukrainian economy, this is a win-win for everyone.
More widespread use of steelmaking slag in agricultural applications will allow society to solve several important issues at once.