On his small plot of land in Kikuyu, Peter Chege grows tomatoes, barley, lettuce, and strawberries on a reservoir of nutrients in water and without soil. Using a technology known as hydroponics, he has eliminated the need to use soil.
Even more incredible is that eliminating soil in growing his plants has led to faster maturity rates and exponentially higher crop yields.
“You really do not need soil or land to grow most crops. Soil is simply a medium that transports the nutrients to the plants’ roots but it can be replaced,” said Mr Chege.
By definition, hydroponics is a method of growing crops using mineral nutrient solutions in water and without soil.
The technology is not Mr Chege’s invention. It has been practised for hundreds of years across the world. In modern-day agriculture, hydroponics has proven particularly successful in Australia and the United States.
However, Mr Chege is hoping that his efforts to domesticate hydroponics and customise it for the average Kenyan farmer will soon bear results and that it will become commonplace across the country.
An analytical chemist by profession, Mr Chege quit a lucrative job with a pharmaceutical company in 2002 and set up his own investment — Minerals and Allied Ltd. And for nearly a decade, the company manufactured animal feed.
However, two years ago, frustrated by the low quality of raw grain that he received from his suppliers, Mr Chege set out to develop a more efficient way of growing the cereals that are often used in making animal feed in Kenya. This is how he came across hydroponic technology.
“It was the solution I had been looking for. The cost of growing animal feed using hydroponic technology is significantly lower than using land. The yield does not disappoint,” he adds.
A year ago, he upscaled his operations and started building hydroponic systems for interested Kenyan farmers. The sheds that house the system can be as small as 60 cubic metres and can, therefore, be built on small pieces of land even in peri-urban areas.
Mr Chege instals the 60-cubic-metre system at a cost of about Sh100,000. Operating at capacity, the system can produce 200 kilogrammes of barley a day for animal fodder. This is enough to comfortably feed about 10 cows.
It takes between five and seven days for the barley to grow to about 30 centimetres, the size at which many farmers harvest it to feed their cattle. In conventional farming, it would take weeks for the barley to grow to the same size.
The faster maturity rates of plants grown hydroponically have been attributed to the fact that the plants do not have to expend a lot of energy rooting out nutrients from the soil. Additionally, the farmer has near total control over the nutrients the plant receives.
“These plants are able to reach their genetic potential because of the tightly controlled environment,” says Mr Chege.
He noted that the yield of the tomato plants that he grows hydroponically typically tends to be 30 to 50 per cent higher than the yield of the conventionally grown plants.
Although hydroponics relies primarily on water, the system is efficient in managing the resource. Studies have indicated that hydroponics systems are at least 10 times more efficient in water usage in comparison to field farming.
For instance, it takes at most 1.5 litres of water to produce a kilogramme of fodder in a hydroponic system. According to Mr Chege, the same amount of fodder would absorb 90 litres of water in conventional field farming.
Hydroponics achieves this level of water efficiency partly because the water and the nutrients are repeatedly recycled. Evaporation rates in the sheds are lower than those to be found in a shamba and there is no soil to absorb excess water.
The technology has been especially useful in taking the pressure off land that has been stressed by excessive use. Since the plants do not compete for nutrients from the soil, it is possible to accommodate a much higher plant population within a small space.
Mr Chege estimates that barley sprouted fodder grown in a 9 x 6 metre shed can feed the same number of cattle that graze on 1,200 acres of pasture land. Human labour is also minimised as it takes only one or two people to maintain a hydroponic shed.
“This could be the solution to many of our problems in the agriculture sector, from land and water scarcity to labour challenges,” he says.
But despite the many advantages, hydroponics farming is by no means a rosy experience. The technology eradicates soil-borne diseases and pests. However, the risk of plants spreading water-borne diseases is much higher. The plants share water solution, which is often recycled, and an illness that goes unchecked could spell doom for an entire season’s work.
Farmers have to make sure that the water used is uncontaminated and they have to maintain high levels of hygiene in order to avoid the creation of a breeding ground for bacteria and viruses.
Additionally, hydroponic systems can be fragile. Unless a system is automated, plants cannot be left on their own for weeks on end. They need constant care. Temperatures within a hydroponic shed have to be kept low for maximum yield.
In case of automated systems which rely on power, an electricity outage for extended periods of time could spell disaster for the crops and farmers sometimes have to invest in back-up generators.
However, not all plants can be grown hydroponically. Raising tuber or root plants using hydroponics can be tricky and sometimes impossible.
“We have grown onions and I think it is possible to grow potatoes, but it is not easy,” says Mr Chege.
The start-up cost of setting up a hydroponic system, about Sh100,000, may be beyond the reach of some farmers. However, Mr Chege believes that the higher yields more than compensate for this cost