In Summary
  • Since he started farming over two decades ago, Spindler has stuck to this type of farming—a method that was informed by a number of reasons.
  • Still, a number of smallholder farmers are trying their hand at it. Farmer and director of Hydroponics Kenya James Wainaina is using the technology.

Aldric Spindler energetically walks towards one of his mega-greenhouse structures at his farm in Ruiru, Nairobi. It has been a long and busy day for everyone at Red Land Roses (RLR), a 50-acre cut flower farm on the outskirts of the city.

The French agronomist uses unfamiliar farming technology to grow flowers — hydroponics. Hydroponic refers to growing crops without soil. It makes use of water with soluble nutrients necessary for the plant and inert (empty of elements) media (substrate) like sand, rock pebbles, coconut peat, pumice, rock wool, macadamia husks and coffee husks.

“We use inert substrates, and then bring in the minerals used to grow the plants. This way we can control nutrients taken in by plants, whereas in soil one is hardly able to know if they are putting too much of anything,” Spindler said.

The substrate is used to support plants.  In Spindler’s case, he uses murram from the farm and pumice from Naivasha as inert media. The substrate is sieved and grated before use. The medium contains no nutrients. 

Since he started farming over two decades ago, Spindler has stuck to this type of farming—a method that was informed by a number of reasons.

“We wanted to control the growth of plants. The second reason, water is a scarce resource and in hydroponics, one is able to recycle it. We get back the drainage from plants (water and dissolved nutrients).

“So, we make big savings on fertiliser and water because nothing leaks into the soil,” he says. The drained water is recollected, sterilised and reused. Spindler saves 40 to 60 per cent of the water. This means less than 50 per cent of fresh water is returned to the recycled water.

“Another important thing is the protection of the environment because nothing leaks to the soil. We have no nitrate or phosphate getting into the soil,” Spindler says.

Senior lecturer in horticulture at Egerton University Anold Opiyo says the technology is common in the horticulture sector. The technique can be used in agriculture in general, although it is a challenge for small-scale farmers, since it is capital-intensive. It also works best in greenhouses where temperatures are controlled, Dr Opiyo says.

Still, a number of smallholder farmers are trying their hand at it. Farmer and director of Hydroponics Kenya James Wainaina is using the technology.

Hydroponics Kenya is an association that brings small farmers using the technology together.

Wainaina has practised hydropinics for three years to grow vegetables and fodder. He uses the technology to grow fodder and vegetable, “but I apply it more to fodder,” he said.

He first soaks his seeds for four-to-five hours and then incubates them for two days to allow the roots to develop before putting them on aluminium trays to grow. The seeds are then spread on two trays and watered daily with soluble nutrients.

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