Biochar: A game changer in tackling soil acidity

Biochar has the potential of combating soil acidity and enhancing soil fertility.

Photo credit: JESSE CHENGE

What you need to know:

  • Because soil pH (measure of the acidity and alkalinity) is measured on a log scale, soil with a pH of four is highly acidic -it is 10 times more acidic than a soil with a pH of 5.
  • A pH of 7 indicates that the amount of base in the water equals the amount of acid.

“My name is Joe Kariuki. For the past 28 years, I have been training farmers in western Kenya. As the director of GPC (Grow, Prosper, Cultivate), I have witnessed many farmers struggle with soil acidity. This problem has had a detrimental impact on crop productivity and overall food security in the region. Motivated by the urgency of addressing this issue, I embarked on a journey to find sustainable solutions.

The idea is known as 'Signerr'. It aims to introduce the first-ever carbon farming in Kenya while addressing not just poverty but also tribal and regional clashes caused by, among other things, a lack of land to farm on and ways to generate an income.

Because soil pH (measure of the acidity and alkalinity) is measured on a log scale, soil with a pH of four is highly acidic -it is 10 times more acidic than a soil with a pH of 5. A pH of 7 indicates that the amount of base in the water equals the amount of acid. Although some crops are acid-tolerant, most thrive in slightly acidic soil with a pH of 6 to 7. Plants have more access to nutrients in this pH range than in more acidic or basic soils.

In Bungoma and Kakamega counties, soil pH levels vary depending on agricultural practices, climate and soil type. These regions are known for their highly weathered soils, which are often characterised by acidity.

Some studies and reports suggest that the average soil pH in Bungoma and Kakamega counties ranges from slightly acidic to moderately acidic. The pH levels typically fall within the range of 5.5 to 6.5.

I have come across the immense potential of biochar in combating soil acidity and enhancing soil fertility. Previously, I was recording low crop yields at my farm caused by the acidic nature of the soil.

I decided to introduce biochar as an alternative to the expensive and hard-to-access lime that I had previously relied on. To my amazement, the impact of biochar on my farm was tremendous.

Convinced of its potential, I conducted a study alongside a group of local farmers. These farmers implemented biochar practices, allowing us to compare their results with a control group. The findings were remarkable.

Our study confirmed the immense potential of biochar in addressing soil acidity and improving crop productivity. It was a game-changer for the farmers who implemented it.

Inspired by the transformative power of biochar, I eagerly adopted this organic fertiliser in my farming practices. Not only did it rectify soil acidity and enhance nutrient availability, but it also reduced my reliance on expensive synthetic fertilisers. Biochar was a sustainable and cost-effective solution, revolutionising my farming practices.

Recognising the need to empower more farmers to adopt sustainable soil management practices, I embraced my role as an extension worker in the region. Armed with my own experiences and the knowledge gained from the study, I conducted training sessions. I spread awareness about the incredible benefits of biochar and organic farming. Through these efforts, I hoped to inspire more farmers to join the biochar revolution and contribute to a sustainable future.

Biochar is just one piece of the puzzle. By combining various soil management practices with the support of extension workers, farmers can achieve long-term soil health and crop productivity.

Despite progress, farmers continue to face challenges due to unsustainable land-use practices. These practices have taken a toll on food security in the country, especially in regions like western Kenya.”