Hydroponics: Growing crops without soil

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The less than 10-minute drive to Lake Flower Company located at the heart of the sprawling Kihoto Estate in Naivasha is nothing to write home about. It is a stretch with smelly garbage heaps littering all over the back street of the densely populated estate.

With lots of wind and swirling dust, Naivasha town lives to its billing of being a dusty lakeside town. But our entry into the farm, which is among more than 50 horticultural farms within the vast constituency in the new Nakuru County, reveals a sharp contrast – the whiff of fresh air. It is welcome relief.

A simple gate belies the well-constructed polythenecovered greenhouses that dot the farm and their uniformity gives the impression of a business investment worth millions of shillings.

The heavy presence of women workers is unmistakable; where working as busy as bees they try to outdo each other, picking roses against a horizon that appears endless. At the pack houses, the story is the same. Just by the look of the farm, one becomes eager to get in to learn the art of growing flowers from the real players in
the multi-million flower sector. But that does not prepare us well for what to expect in the greenhouses. Whereas it is the multi-coloured roses (which are a sight to behold) and how they are grown that we are looking forward to seeing, it is the technique used to grow them that catches our attention – hydroponics!

Though new to many in Kenya the technique, which involves growing crops without soil, has been in use in Naivasha for a while. It is now gaining credence by the day with many farms in the area jumping on board to adopt it, and it is giving them options that are proving to be commercially viable.

Those we spoke to say it is a global trend that will revolutionise the farming industry. “It is an expensive venture but the returns are handsome,” Mr Jonah Wanjala, the production assistant and our guide to the farm tells us. Hydroponics, drawn from the Greek word hydro meaning water and ponos labour, is the term given to “soil-less” cultivation.

In natural conditions, soil acts as a mineral nutrient reservoir but is itself not essential to plant growth. When the required mineral nutrients are introduced into a plant’s water supply artificially,
soil is no longer required for the plant to thrive.

Hydroponics involves growing plants in water laced with nutrients or in an inert medium which could include gravel, pumice and coco peat among others and is suited to locations where land is
scarce or soil is of poor quality. The medium doesn’t supply any nutrition to the plants.
In soil, plants grow large root systems that search for food and water but in hydroponics, nutrients are fed directly to the roots from the nutrient solution (water and fertiliser combined) enabling plants to spend more time growing above the surface. “With this farming technique, production is higher by 20 per cent compared to growing flowers in the soil,” Mr Wanjala says. Though the initial costs of setting up hydroponics can be prohibitive, the gradual returns are encouraging. “One is able to recoup at least three years after the investment,” he adds.

Also, consistent production is assured regardless of outside conditions such as weather vagaries. At the farm, which specialises in growing roses, 50 per cent of the flowers are grown directly in the soil and the remaining half using hydroponics.Planted on almost 100 metre long troughs, the roses form a striking uniformity in straight rows. The troughs used in this farm are black and carefully placed on raised beds. The beds make harvesting easier for flower pickers and it is less tiresome.

“Pipes are laid in the troughs for watering purposes,” says Mr Wanjala. At the end of the rows are posts to support the beds with long poles supporting the greenhouses from inside. But the expertise and the combination of workmanship used are amazing.

Explaining the intricacies involved in the farming method, the production expert says the farm uses coco peat and pumice as mediums because they are readily available in the area.

“We mix the two to a ratio of 50:50 to attain the desired results,” he says. “In the system, water use is minimal, evenly distributed, stays in the troughs for long and can be recycled. Fertiliser use is also controlled and
you get more for less,” Mr Wanjala says.

“Besides this, soil borne diseases and pests are easily controlled with less use of pesticides while weeding is minimal since roses are grown in a near germ-free environment that is in clean condition for harvesting and planting,” adds the production assistant.

Hydroponics is often practiced inside greenhouses that regulate humidity and carbon dioxide levels to produce the highest level of growth and productivity. There are two main types of hydroponics – the solution culture and medium culture.

Solution culture does not use a solid medium for the roots, only the nutrient solution. The medium culture method has a solid medium for the roots. Although the disadvantages of using the concept are not many, experts say the system involves huge investment and is therefore suited for high valued crops. The process involved is technical and needs skilled people to handle procedures such as mixing nutrients and maintaining correct acidity levels.

Hydroponics units require electricity or an alternative source of energy to maintain the right temperature, which could be costly.

“Hydroponics gardens are also susceptible to power blackouts. The equipment that gives the plants the nutrient solution has to be powered. If you experience a power blackout the plants might quickly dry up and you will have to water your gardens by hand if this happens,” Mr Wanjala says. According to Mr Joseph Kariuki of Lake Naivasha Growers Group (LNNG) more and more farmers in the area now prefer hydroponics compared to conventional cultivation.

“The system is also environmental friendly, at the time we are advocating conserving the environment,” he sums up.