By Caroline Mwendwa
ON GRADUATING WITH a Bachelor of Science degree in Agricultural Engineering, Dennis Murithi worked with farmers offering extension services in installing irrigation systems and vertical garden technologies to improve crop yields. From experience, even after installing these technologies, most farmers still faced challenges in low crop yields, caused mainly by soil infertility, highly characterized by low organic matter in the soil. Driven by the desire to provide a solution to this challenge, Dennis collaborated with his friend, Derrick Ngigi, and together they founded Pure Plant Organic Ltd. This company offers soil amendment solutions to farmers. They began by conducting research on existing technologies that aim to sustainably enrich the soil with organic matter.
“We found that farmers who have embraced organic farming practices such as vermicomposting, rearing black soldier flies for animal feed as well as organic manure, and other composting technologies, struggle less with soil fertility,” says Murithi. Further research led them to identify a solution that lasts longer in the soil, biochar technology.
Biochar technology
Biochar is a solution for improving soil health. Its primary purpose is to amend the soil so that it is conducive to microorganisms’ activity, allowing them to multiply and aid the process of nutrient absorption by plants.
The process of making biochar
To make biochar, one requires biomass such as rice husks or macadamia shells. Muriithi acquires his biomass from rice millers in Mwea, Kirinyaga County, which is then taken through the pyrolysis process, whereby they are burnt in the absence of oxygen, at different temperatures. A milling machine then crushes the burnt material to reduce the size of the particles into fine granules, which are then inoculated with organic fertilizers. The final material is highly effective, and can be applied alone, without the need to add other types of fertilizer.
How biochar works
Since the soil contains living microorganisms, the continued use of synthetic fertilizers and herbicides kills them, leaving the soil dead and unproductive.Avoidance of these synthetics and replacing them with organic manure restores the presence of microorganisms. When biochar is added to such soil, it acts as a point for these microorganisms to multiply due to the porous nature of biochar. This porousness also enhances the aeration of Is your soil dead? Bring it to life with biochar the soil and moisture retention, conditions that boost soil productivity. Additionally, biochar helps in balancing the soil PH.
“Biochar does not decompose, since due to the process of pyrolysis, it retains a stable carbon compound that lasts permanently in soil,” he says.
How to determine the quantity of application
Before applying biochar on the farm, a soil test is recommended to determine the condition of the soil. The type of soil also determines the amount and frequency of application. For example, clay soil requires more biochar due to its characteristic of forming hard pans.
“The greatest advantage of biochar is that it does not decompose, and farmers who grow crops at a small scale may not need to apply additional manure after applying biochar,” says Muriithi. Commercial producers, on the other hand, might need to add other biofertilizers, but in smaller quantities, once biochar has been applied.
Pure Plant Organics has recorded success stories from farmers who have applied biochar to their previously dilapidated farms. “For example, a farmer in Mwea,
used to harvest 7 bags of rice in 3 seasons, but is now harvesting 20 bags of rice after applying biochar on her farm,” he says. In areas where the soils are clay, farmers who could not grow crops due to hard pans can now grow crops and harvest satisfactorily, having amended the soil with biochar.
“Landscapers also form a huge part of our clientele, given that home compound grass requires conditioning after 3 months of planting, and instead of using compost manure, which comes with an unpleasant smell, they apply biochar,” he quips.
Availability to farmers
Pure Plant Organics packages biochar in various quantities. A 5 kg pack goes for Ksh 250, 10 kg pack goes for Ksh 500, 25 kg pack goes for Ksh 1,500 and a 50 kg pack goes for Ksh 2,200. “Our outlet is based in Nairobi, but we supply to customers across the country.
We are already serving farmers in the Central, Western, and Rift Valley regions of Kenya. We do not just send the biochar, but walk the journey with the farmer, right from conducting soil testing to guiding the farmer on quantities to apply and following up to check the improvement of the soil and its productivity,” he says.
Muriithi encourages farmers to adopt new technologies that offer solutions to the challenges they face. He asserts that biochar from Pure Plant Organics is certified by KEBS, Kilimo Hai, and ECO Cert.
Challenges
One major challenge faced by the duo is the misinformation that comes with a new product in the market and the gaps in regulation.
“Secondly, farmers do not differentiate between biochar and charcoal dust, but we are working with the organic input manufacturers association to create more awareness on biochar.”
Looking ahead
To scale up the enterprise, Pure Plant Organics is working to increase production capacity from the current 70 tonnes per month to 100 tonnes. To achieve this,
they are already constructing a dryer, to spread out the pyrolyzed biomass powder, to dry so that it does not absorb moisture, as it awaits milling.
Establishing collaborations is another approach they have adopted to reach more clients. “Since urban and peri-urban dwellers with kitchen gardens and backyard plants are our regular customers, we have partnered with Killicycle.
This is an organization that encourages families in the urban areas to recycle organic waste by selling them composting bags to put all organic waste and produce vermijuice to use in their gardens. Once in a while, we take the excess waste in exchange for biochar,” says Muriithi.
With the passion to enable farmers to produce optimally, these young entrepreneurs are changing the soil fertilizer space with sustainable soil amendment solutions.