alexa With water pans, we grow crops all-year round - Daily Nation

With water pans, we grow crops all-year round

Friday July 11 2014

A water pan used for growing crops at Mully

A water pan used for growing crops at Mully Children’s Family farm in Yatta. Pauline Kairu | Nation 

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The five-foot maize plants tower above Nicholas Mbithi as he walks around his farm with a hoe, occasionally weeding the crops.
Few metres from the maize, red onions shine in the mid-day sun.

Some lemon, mango and pawpaw fruit trees stand amid the onions. For the last four years, Mbithi has harvested in plenty from the farm.

The contrast is evident in nearby farms. Two seasons of failed rains and a scorching sun have left maize struggling to survive.

Most of the farmers in the village named Kanalu, in Machakos County, as others across the region, may be seeking food aid soon. Others, having lost hope, are grazing their livestock in the maize farms.

But for Mbithi, it is another season of a bumper harvest. He tells Seeds of Gold that he expects to harvest about 30, 90kg bags of maize worth Sh100,000 from the two acres.

So what is his secret? Mbithi and 23 other farmers are using water pans and lagoons. They formed Meko Maseo Self Help Group in 2001 to find solution to the erratic rains problem after attending a Ministry of Agriculture seminar on construction of water pans in Machakos.


The members divided themselves into two groups of 12 people each. They dug a water pan for each member during the dry season.

“The type of soil in this area is black cotton, which can hold water for a long time,” he explains.

Mbithi dug a 600-metre square water pan on his farm. The pan collects run off water during the long rains season in April.
The water stays in the pan for three months, enabling him to use it to irrigate crops on his three-acre farm.

“Maize takes four months to mature. The three months that I irrigate my plants are enough to ensure growth because by the last month, the maize in the cobs will be maturing and the beans would have been harvested by then.”

The pan takes a week to fill during the April rains season and about a month during the October short rains.

“You cannot rely on rains at all,” says Charles Mulli who once worked at the Kakuzi farm in Makuyu, from where he got the idea of using lagoons to store water.

Like many other farmers in Yatta, Ukambani, he was apprehensive about the rains.

The area receives not more than 750mm of rain per year, mainly in March and April and November and December.

In 2005, Mulli constructed the first concrete lagoon on the land he bought in 2001. Three others were constructed in 2006 and in 2008.

“We tap rainwater using gutters on greenhouses that occupy our six acres, as well as other buildings. We then channel the water into trenches and it ends up in the dams.”

The dams are constructed in valleys around the farm and are connected to each other using spillways in such a way that if the first one fills, then water flows to the next one.

“We are able to plant French beans four times a year because of the dams,” says Mulli, who sold his property, mobilised funds from abroad and added to his savings to set up Mully Children’s Family farm, which sits on 200 acres.

Joshua Nyalita, the general manager at the farm, says the water they collect is enough for their farming needs for more than a year.

Although only 25 acres is under cultivation, Nyalita says with expansion of the dams, they will grow more crops. Currently, they use 100 cubic metres of water per day during the dry season.

The farm produces about 100 tonnes of tomatoes in eight months and 70 tonnes of French beans for export, among other crops.
It has EuroGAP (Good Agricultural Practices) certification, meaning they have to be keen on the water they use.

“Small-scale farmers ask themselves, can I make it? It is simple. They should harvest water from the roof of their houses or greenhouse for those using them and store in reservoirs, then use when the rains stop to sustain their crops. Farmers should also consider pooling resources together to construct lagoons.”

Minimising evaporation

To slow down the rate of evaporation during the dry season, Mbithi sprinkles wood ash on the surface of the water.

Evans Chimoita, an agricultural economics lecturer at the University of Nairobi, who is currently doing a research on zero-rain fed farming in the arid areas of Lower Eastern region, says Mbithi’s use of ash is innovative, but it has not yet been proven scientifically.

“I believe that if you use wood ash with very fine particles, the contact of water with the atmosphere would be reduced greatly hence minimising evaporation but too much of the ash will interfere with the PH of the water overtime making it inappropriate for irrigation,” he says.

He advises farmers to sprinkle water-holding micro-fibre polymers available at agrovet stores on the surface of the water to prevent evaporation.

“Another good substance is polystyrene, which is used in packaging electronic items. This can be cut into pieces and recycled but the best option would be an absorbent polymer, which is mixed with the water,” he says.

According to him, absorbent polymers can hold water for up to 120 days.

Chimoita advises farmers in all regions to dig pans in spherical or oval shape because this reduces the evaporation rate.