By Nita Bhalla

KITUI, Kenya, June 6 (Thomson Reuters Foundation) - Kenyan farmer Abel Mutie Mathoka believed it needs to be a joke when he was told he could water his drought-hit crops more cheaply, easily and efficiently utilizing a pump fuelled by cotton waste.

"Who could think it's possible to make a fuel better than diesel from cotton seeds? I didn't!" laughed Mathoka, bending down to examine the watermelons on his 10-acre (four-hectare) shared plot in Ituri town in Kenya's southeast Kitui county.

"But it works," he said, walking over to a close-by tree and plucking a large green pawpaw. "Irrigation with this biodiesel water pump has actually helped me get greater yields, particularly throughout dry spell periods."

Mathoka stated his incomes had doubled in the two years he has been pumping water using biodiesel, which is both more efficient and 20 shillings ($0.20) per litre more affordable than routine diesel.

The biodiesel he is using is not just excellent news for him - it is also excellent news for the world.

Unlike most biofuels, which are obtained from crops such as maize, sugarcane, soybean, rapeseed and jatropha, it is made from a byproduct of the cotton-making procedure.

That suggests that in addition to being cleaner and cheaper than regular fuel, it is more sustainable than other biofuels since no additional land is required to produce it.

From Brazil to Indonesia, the rush to cultivate biofuel crops has driven forest neighborhoods off their land and pressed farmers to switch from crops-for-food to more successful crops-for-fuel - worsening food lacks.

"Our biodiesel originates from crushing cotton seeds left over as waste after ginning - the process of separating the seeds from raw cotton," said Taher Zavery, handling director of Zaynagro Industries Ltd, the Kitui-based business producing the biodiesel.

"We started producing and using it to power our cotton ginning factory in 2011. With increased production, we now use it for our trucks, sell it to the United Nations to run some of their buses - and also to regional farmers for irrigation."

More than 1,200 farmers in Kitui have so far purchased biodiesel pumps for irrigation as part of an initiative released by Zaynagro in 2015, said Zavery.

DRY RIVER BEDS

Climate change is taking a toll across east Africa and increasingly unpredictable weather is becoming commonplace in countries such as Kenya, Somalia, Uganda and Ethiopia, resulting in lower rainfall.

The recurring dry spells are ruining crops and pastures and are starving animals - pushing millions of individuals in the Horn of Africa to the brink of .

The variety of Kenyans in need of food help in March surged by almost 70 percent over a period of eight months to 1.1 million, largely due to bad rains, according to federal government figures.

With nearly half Kenya's 47 counties declared to have a severe scarcity of rain, humanitarian agencies are cautioning of increased appetite in the months ahead.

"Only light rains is forecast through June ... and this is not anticipated to alleviate dry spell in impacted areas of Kenya and Somalia," stated the Famine Early Warning Systems Network in its latest report.

"Well below-average crop production, bad animals body conditions, and increased local food rates are anticipated, which will lower poor families' access to food."

In Kitui's Kyuso location, the indications are already obvious.

Rivers, water pans and dams are drying up as an outcome of the extended dry spell.

Villagers suffer trekking longer ranges - sometimes more than 10 km (6 miles) with their donkeys laden with empty jerry cans searching for water.

Small-scale farmers, the majority of whom depend on rain-fed agriculture, go over strategies to sell their goats to make ends meet if the harvest is bad.

BATTLING DROUGHT WITH BIODIESEL

But not all Kitui's farmers are stressed.

A little however growing number are shedding their burden of dependence on the weather condition - and investing in irrigation systems powered by Zaynagro's cotton seed biodiesel through a pay-as-you-go scheme launched more than three years back.

Neighbouring farmers unite to purchase the watering system - which includes the biodiesel pump, 12 metres of pipes and 10 litres of biodiesel - at costs beginning with 32,000 shillings, depending on the size of the pump.

The farmers make an initial payment, then pay interest-free monthly instalments until the total is settled. They purchase the biodiesel to run the pumps from Zaynagro at 80 shillings a litre.

Farmer Alex Babu Kitheka, 39, said the biodiesel pump permitted him to water a bigger part of his one-acre plot, where he grows a variety of vegetables consisting of maize, tomatoes, spinach and sweet potatoes.

"With a diesel pump, maize yields were lower and I would get 15,000 shillings in three months. With the biodiesel pump, I can earn 45,000 shillings," said Alex Babu Kitheka, standing near his plot in Ilangilo village, 40 km (25 miles) from Kitui town.

CIRCULAR ECONOMY

Other farmers indicate the scheme as a major benefit in assisting enhance their output.

"The instalment scheme is good. Most farmers do not have the cash and can not quickly get a loan to buy a pump like this," stated Maurice Kitheka Munyoki, 41, as he stood beside his blue biodiesel pump.

"Having a scheme like this assists us a lot. Our yields are excellent which indicates we can pay off the cost of the pump slowly in little amounts, and have money left over to pay the school charges."

Zaynagro's effort is still in its early phases, with few farmers having actually repaid the complete cost of the pumps.

But such biofuel schemes are appealing because they produce a circular economy by turning waste to biofuel for profit, stated Sanjoy Sanyal, senior associate for Clean Energy Finance at the World Resources Institute.

The simpleness of the model - user friendly, robust technology, guaranteed supply of biodiesel combined with a pay-as-you-go scheme - might help electrify rural Africa, he stated.

"There is a mosaic of sustainable energy alternatives on the planet. The key concern is testing ideas and methods in a collaborative style," stated Sanyal.

"Other cotton ginning factories in the area must try and gain from this experiment. Financial institutions should begin try out loans to groups of farmers. International donors and financiers require to support experimentation."

($1 = 101.3000 Kenyan shillings) (Reporting by Nita Bhalla @nitabhalla, Editing by Claire Cozens. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, females's and LGBT+ rights, human trafficking, home rights and climate change. Visit http://news.trust.org)