Sea water technology to end farmers' drought woes

A new system that allow food crops to be irrigated with seawater is being trialled by the University of Surrey in the UK offering a potential miracle for Kenyan coastal farmers grappling with a scarcity of fresh water for their produce, even as they live beside a huge water mass.

According to the UK researchers, led by Professor Adel Sharif, 97.5 per cent of the world's water is salty and not usable for the great majority of agriculture. Farmers and local NGOs have tried to resolve this by working to adapt soils to the salt levels, but with poor results.

Related Articles

 

Agricultural growth slowed 2011 on drought
A slowdown in the growth of Kenya's agricultural output in 2011, which rose 1.5 per cent compared with a rise of 6.5 per cent in 2010, has been held up as the key factor dampening overall economic growth last year - which ran at 4.4 per cent, compared with growth of 5.8 per cent a year earlier.
According to data in the Economic Survey 2012, released by the Kenya National Bureau of Statistics and the Ministry of Planning last week, the slowdown in agriculture — Kenya’s key economic driver, employing over 80 per cent of the country’s labour force and accounting for quarter of the country's GDP - was due to unfavourable weather in some regions, and the weakening of the Kenyan shilling, which increased the prices of farm inputs.





The outcomes emphasise how closely linked agriculture is to the overall performance of the economy.
All the country's major crops registered declines in production in 2011, except for rice, cotton, pyrethrum and sisal, which were driven upwards by the emergence of new markets, such as cotton exports to China. Global supply constraints also resulted in better prices for tea and coffee. However, tea output dropped in the first quarter of 2012, due to depressed rainfall, with many tea growing regions also suffering severe tea frost.
Wheat production recorded the biggest dip in production to 105,000 tonnes in 2011 from 200,000 tonnes in 2010, due to a severe drought that hit the main producing areas around Narok that contribute an estimated 40 per cent of the national crop. However higher prices at the international and local markets increased the value of some of the crops.
“The value of marketed maize production, for example, more than doubled from the 2010 levels to Sh10.1 billion, mainly as a result of higher prices paid to farmers,” the Economic Survey 2012 said.
At 4.4 per cent, Kenya’s economic growth stands at less than half the 10 per cent target the country needs to achieve and sustain in the next 18 years to realise the goal of becoming a middle income state by the year 2030.
Written by Bob Koigi for African Laughter

Experts redraw insurance model to protect drought-stricken herders
The development of the financial services sector, fast-tracked through international initiatives, is emerging as potentially transformatory for agriculture in East Africa, with up to 40,000 farmers in Kenya and Rwanda now set to gain from an entirely novel insurance scheme designed to protect regional farmer’s from losses to crops and livestock caused by bad weather.

new cabbage offers respite from pests and droughts
Quisor F1 is a new hybrid Dutch cabbage introduced commercially to Kenyan farmers in  May by Syngenta East Africa. The cabbage has a waxy texture that makes it highly resistant to attack by moths and has expansive root network that makes it highly drought tolerant. The Quisor F1 yields are also more uniform if well tended.

rainwater experts launch projects to end drought for farmers
Even as the rain pours, we are beset with warnings that as soon as the rain stops we shall return to drought and water shortages. In Nairobi, the tap water rationing still continues. The problem, says UNEP, is not the rainfall, but the water waste. If we harvested the rainfall, we would have plenty of water, and water harvesting isn’t even expensive.

Farmers in the Taita Taveta area of Mombasa, who predominantly grow cassava, onions and tomatoes, have been supported by several NGOs to apply simple water purifying techniques, and treat soils to adapt to salty water. “But nothing has ever changed. We get very high yielding crops, but the returns are ever poor thanks to lack of fresh water,” said Mwakazi Kizombe, a farmer in the area who has worked with more than 10 different organisations in seeking a solution to the fresh water shortage.

However, the low-cost UK solution, which the scientists hope to roll out world wide in three years time, will make seawater irrigation on a large scale a realistic and sustainable solution to food supply problems, without either high pressure pumps or expensive distillation units. Instead, the new approach makes use of the natural process of evaporation alongside a membrane designed to retain the impurities in the water, including the salts, allowing only pure water to reach the plants.

The project has built on Professor Sharif's work on Manipulated Osmosis Desalination (MOD), which is used in Gibraltar and Oman to produce drinking water for human consumption. MOD is currently the leading technology for desalination, reducing energy use by up to 30 per cent compared to conventional desalination plants.

The University team is now working alongside governments and disaster relief NGOs worldwide to deliver community-scale sustainable technology to improve water for drinking, sanitation and agriculture.

The project sits beside another one for African and Pacific countries called The Seawater Greenhouse, which aims to create fresh water from seawater using an adapted greenhouse.

The technology gravitates or pumps sea water and uses it to humidify and cool the air inside a greenhouse, and then uses solar panels to evaporate and distill fresh water.

Later, the humidified air is expelled from the greenhouse and used to promote the growth of plants outside and the slightly more concentrated residual seawater is returned to the ocean.

Kenya is a officially classified as a water stressed country, but it has a 500 km coastline. Water harvesting, which government has worked hard to advocate, hasn't picked up fast enough as farmers still count on disappointing rains. “If we can inculcate this irrigation by sea water, then embrace rain water harvesting, then farmers in the whole country can grow whatever they want anytime of the year, which is where we want to move agriculture to,” said Matilda Nzioka from the Ministry of Agriculture.

Written by Bob Koigi for African Laughter

• < Prev
• Next >