Without soiling my hands, I produce excess vegetables

The hanging garden: Hydroponics farmer Kirogo Mwangi at his farm in Lavington, Nairobi. The new farming technology requires expertise, but it pays good dividends. PHOTO | BILLY MUTAI | NATION MEDIA GROUP

What you need to know:

  • The fact that soil is not involved in this form of agriculture has made many people to think that hydroponics is a shortcut to food production. Nothing could be farther from the truth.
  • Animal Breeding and Genomics professor Alexander Kahi of Egerton University’s Faculty of Agriculture says most vegetables and grass can be grown through hydroponics.
  • Mwangi, 51, ventured into this form of urban farming in 2012, and two years later, green produce from the hanging gardens is sustaining his family. At times, the produce is more than they can consume and they share it with two children’s homes.

On the edges of an estate in Lavington, Nairobi, there are rows after rows of green, leafy spinach, coriander and rosemary.

On a pavement, right in front of the gate, are bushes of hanging capsicum, eggplants and celery leaves.

And as we walk into Kirogo Mwangi’s house, we are greeted by more and more crops on stands, dancing to the morning breeze.

While these crops look healthy, with enough nutrients, sunlight, water, their visible roots are not in the soil.

Welcome to hydroponics farming. A subset of hydroculture, hydroponics is a method of growing plants and crops using mineral nutrient solutions in water, without soil.

Mwangi, 51, ventured into this form of urban farming in 2012, and two years later, green produce from the hanging gardens is sustaining his family. At times, the produce is more than they can consume and they share it with two children’s homes.

“It has been rewarding as now we eat fresh, nutritious and safe vegetables. Growing your own food gives you power and dignity. You know exactly what you’re eating because you grew it,” the public health consultant tells Seeds of Gold.

The fact that soil is not involved in this form of agriculture has made many people to think that hydroponics is a shortcut to food production. Nothing could be farther from the truth.

According to Mwangi, just like soil-based farming, raising vegetables like spinach using hydroponics technology begins with growing the seeds in a nursery.

Instead of soil, hydroponics farmers grow their seeds in cocopeats that are formed from crashed coconut shells. The cocopeats facilitate germination of seeds besides holding the shoots in place.

“For hydroponics to be successful, you need to start off the plant in an inert substance and not soil. Therefore, the plant is never affected by pathogens from the soil and other diseases. So the transition into water is smooth,” says Gichui, Mwangi’s son who has been helping his father with farm work together with his mother, Veronica.

MIXTURE OF NUTRIENTS

Next to Mwangi’s nurseries are two buckets one on top of the other. These, we learn, are called Dutch buckets and they contain a mixture of nutrients and fertiliser for the germinating seeds.
The buckets have a pipe fixed at the bottom that allows the dissolved nutrients to flow into the nursery trays when lifted. The system is designed in a way that it allows excess water and nutrients to flow back into the buckets.

From the beds, the seedlings are transplanted to container gardens like the ones bursting at the seams with strawberries and capsicums in Mwangi’s garden.

The garden is full of stands that Veronica and Gichui designed. The letter A-shaped structures have row after row of ascending roofing pipes cut out like egg trays where the plants grow from tiny cups.  The cups have four holes at the bottom and float in the pipes full of water and nutrients.

“The best thing about this is that we use recycled waste pipes from construction sites and we can plant more vegetables this way than on the ground. We are growing more vegetables than we can consume,” Mwangi says.

The town farmer says he spent Sh20, 000 on the pipes, plastic cups and seeds — a one-off investment.

In addition to hydroponics, Mwangi grows vegetables and fruits in the soil outside his house under drip-irrigation. He produces his own manure through vermiculture — where red worms decompose all the green waste from the kitchen. He buys the worms from local dealers at Sh10 per worm.

Vermicomposting is the process of using worms and other microorganisms to turn kitchen waste into black, earth-smelling, nutrient-rich humus.

“The worms breakdown the waste and release particles called casting, which look like humus. Consequently, there is no emission of the pungent smell,” Mwangi explains.

A PLACE FOR THE WORMS

The box for vermicomposting systems, he says, must be able to retain both moisture and air while providing a place for the worms to live or else they die.

Animal Breeding and Genomics professor Alexander Kahi of Egerton University’s Faculty of Agriculture says most vegetables and grass can be grown through hydroponics. They include cabbages, kale, spinach, grass, maize, sorghum and lettuce.

The nutritional value of hydroponics produce as compared to crops grown in the soil, Prof Kahi says, depends on the crop grown.

The don with an interest in hydroponics says, for instance: “Barley grown hydroponically could be rich in proteins, while that grown on the soil would be rich in carbohydrates.”

He adds that the nutritional value of vegetables depends on the quantity and quality of nutrients added to the water and cautions farmers against adding nutrients in hydroponics fodder.

“If you are growing fodder using hydroponics technology, do not to add any nutrients to the water as this may lead to poisoning of the animals after consuming the fodder,” he says.

Both Mwangi and Prof Kahi agree that hydroponics is labour and capital intensive. In addition, Prof Kahi notes that hydroponics requires high level of expertise and that there is no ready market for its produce. Other challenges are attack by pests such as rats.

Nonetheless, these have not deterred the Mwangis from learning more on hydroponics.