Chege’s farm in Limuru near Nairobi has become a training ground for curious farmers eager to adopt the technology. An analytical chemist, Chege has been teaching other farmers from around East Africa the intricacies of hydroponics. The venture has improved his financial status and is gaining him admiration from people across the region.
Though a fresh concept quietly spreading among Kenyan smallholder farmers, the technology is not exactly new. Hydroponic agriculture was invented about a hundred years ago in Australia and has since spread to countries all over the world. In hydroponic farming, crops are grown without soil using mineral nutrients solutions. When mineral nutrients dissolve in water, they become easily absorbable by plants through the roots. Those who practice this form of farming say that soil is simply a medium for holding nutrients and is therefore not an essential component in the growth of plants.
A local agricultural extension officer, John Ngamau, says the technology is fast gaining ground, especially in central Kenya. It’s a major boost to the agricultural sector and is helping to fight hunger and poverty in the area.
“In central Kenya, where a majority of farmers own less than an acre of land, the hydroponic system is renewing the hopes of many people who want to embark on farming but are prohibited by the size of their land,” he said.
Chege used to manufacture animal feed for sale, but getting the fodder for the raw material proved difficult.
“That’s when I thought of hydroponic farming, which I had only read about in books but had never seen being practiced. Using the technology to grow fodder for livestock has helped improve the productivity of my pigs,” he said.
Chege no longer manufactures animal feed, instead making a living encouraging farmers to produce enough fodder hydroponically, which ensures more nutrition for their livestock. He speaks highly of the technology.
“It is cheap to adopt, ensures high yields and fast growth of plants, and eliminates soil-borne diseases,” he said.
A farmer needs a shed made of a shade net to ensure temperatures are maintained at 17-24 degrees Centigrade. Aluminum and plastic trays are used for growing the fodder. They help keep temperatures down and are cheap, Chege said.
The hydroponic system is hygienically safe and can be used to grow commercial food crops, fodder for livestock as well as food crops for domestic use. Chege uses the hydroponic system to grow mainly tomatoes, strawberry and fodder. Other crops that can do well with hydroponic farming are broccoli, flowers and other horticultural produce.
Not all crops can be grown using this system, says Chege. Tubers or root crops can be difficult or impossible.
A farmer will need to buy the appropriate seeds he intends to grow. Chege recommends barley seeds for fodder, which he says contain all the required nutrients at the right proportions for animal nutrition and are also readily available since they are not consumed as food by humans. Barley is however used in the manufacture of alcohol.
Water for hydroponic farming should be clean. Another requirement is hydroponic nutrients, which Chege manufactures and sells to other farmers for $3.5o per liter. The solution, which Chege has branded Peter Hydroponic Solution, contains mineral nutrients easily absorbed by plants for fast growth. Farmers learn how to dilute and use the solution.
Hydroponics is credited for greater efficiency in resource management. Studies show that hydroponic systems are at least 10 times more efficient in water usage compared to field farming. For example, it takes 1.5 liters of water to produce a kilogram of fodder in a hydroponic system. A farmer would need to use 90 liters of water to produce the same amount of fodder in conventional field farming, said John Kimani, an agricultural officer.
The system is efficient in water usage because the water and nutrients are repeatedly recycled. The evaporation rate in the sheds is also lower than in an open field. In conventional fields, the soil absorbs water, leading to waste of water and nutrients.
Hydroponic agriculture is credited with enhancing plants to reach their genetic potential as a result of improving maturity rates and crop yields. This is brought about by the highly controlled environment in which crops are grown.
Eliminating soil from the farming process eradicates most pests and soil-borne diseases. The farmer does not incur the heavy costs normally associated with controlling pests and soil-borne diseases, and is more assured of a healthy crop and good harvest.
Land scarcity is a ticking time-bomb in Kenya. Hydroponic farming holds the promise of solving this: Due to its low land use, it is particularly suitable for small-scale farming. All that a farmer needs is a shed. Sheds can be as small as 60 cubic meters – tiny enough for many homes in suburban areas.
It takes five to seven days for a crop such as barley to grow a foot tall, the size at which many farmers harvest it to feed their livestock. In conventional farming, it would take several weeks for the fodder to reach the same height.
This mode of farming is relatively cheap. Installing a 60-cubic-meter system costs about $1,176. But in a country where poverty is endemic, raising this amount is an uphill task for many small-scale farmers. Although high yields compensate for start-up costs, the initial outlay is way beyond the reach of many peasant farmers.
Operating at full capacity, a 60-cubic-meter system would give a daily yield of 200 kilograms of animal fodder, enough to feed 10 cows. A farmer would need to invest much more for a conventional field to yield that amount of fodder.
These high yields are experienced in other crops as well.
“The yield I get from tomatoes grown hydroponically tends to be 30- to 50-percent higher than yields from conventional fields,” says Chege.
But like any other technology, the hydroponic system has its challenges. The danger of spreading waterborne diseases is ever present, and the fact that the mineral solution is recycled makes this risk even higher.
A disease that goes undetected could wipe out the yield of a whole season, bringing huge losses to a farmer. To eliminate the risk of waterborne diseases, farmers are advised to ensure the water used for mixing the mineral nutrients is uncontaminated. High standards of hygiene are a must in the sheds – and water containers – to eliminate possible breeding sites for pathogens.
The hydroponic system is delicate and requires close and constant care. Failure to take the necessary care can be disastrous. Unless the fragile system is automated, the crops cannot be left unattended for long.
Farmers who want to learn the new technology must enroll for a one-month training period. The fee, according to Chege, depends on how fast a farmer can learn. Training costs $12 per day, and a farmer can go for as many days as he needs to understand the system. But even this seemingly minor cost is steep for many poverty-stricken small scale farmers.
Ngamau applauds the technology, describing it as “cheap, efficient and highly productive.” The challenges encountered in conventional farming, he said, should not discourage those who want to adopt the system because the final yields compensate for any challenges.