By Nita Bhalla

KITUI, Kenya, June 6 (Thomson Reuters Foundation) - Kenyan farmer Abel Mutie Mathoka believed it must be a joke when he was informed he might water his drought-hit crops more inexpensively, easily and efficiently using a pump sustained 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 inspect 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 nearby tree and plucking a big green pawpaw. "Irrigation with this biodiesel water pump has assisted me get higher yields, specifically during drought periods."

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

The biodiesel he is utilizing is not just excellent news for him - it is also good news for the planet.

Unlike most biofuels, which are derived from crops such as maize, sugarcane, soybean, rapeseed and jatropha curcas, it is made from a by-product of the cotton-making process.

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

From Brazil to Indonesia, the rush to cultivate biofuel crops has actually driven forest communities off their land and pushed farmers to switch from crops-for-food to more rewarding crops-for-fuel - exacerbating food scarcities.

"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, managing 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 utilize it for our trucks, sell it to the United Nations to run a few of their buses - and also to regional farmers for watering."

More than 1,200 farmers in Kitui have up until now bought biodiesel pumps for watering as part of an initiative launched by Zaynagro in 2015, stated Zavery.

DRY RIVER BEDS

Climate change is taking a toll throughout east Africa and progressively irregular weather is ending up being commonplace in countries such as Kenya, Somalia, Uganda and Ethiopia, leading to lower rains.

The repeating dry spells are destroying crops and pastures and are starving animals - pushing millions of people in the Horn of Africa to the brink of severe appetite.

The variety of Kenyans in need of food aid in March surged by nearly 70 percent over a period of eight months to 1.1 million, mainly due to poor rains, according to federal government figures.

With practically half Kenya's 47 counties declared to have a serious shortage of rain, humanitarian agencies are warning of increased appetite in the months ahead.

"Only light rainfall is forecast through June ... and this is not expected to minimize dry spell in impacted locations of Kenya and Somalia," said the Famine Early Warning Systems Network in its most current report.

"Well below-average crop production, poor livestock body conditions, and increased regional food costs are expected, which will reduce bad families' access to food."

In Kitui's Kyuso area, the signs are already obvious.

Rivers, water pans and dams are drying up as an outcome of the prolonged drought.

Villagers experience trekking longer distances - often more than 10 km (6 miles) with their donkeys loaded with empty jerry cans looking for water.

Small-scale farmers, the majority of whom depend on rain-fed agriculture, talk about plans to offer their goats to make ends meet if the harvest is poor.

BATTLING DROUGHT WITH BIODIESEL

But not all Kitui's farmers are stressed.

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

Neighbouring farmers band together to invest in the irrigation system - which includes the biodiesel pump, 12 metres of pipelines and 10 litres of biodiesel - at expenses starting from 32,000 shillings, depending on the size of the pump.

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

Farmer Alex Babu Kitheka, 39, stated the biodiesel pump allowed him to water a larger part of his one-acre plot, where he grows a range of veggies including maize, tomatoes, spinach and sweet potatoes.

"With a diesel pump, maize yields were lower and I would get 15,000 shillings in 3 months. With the biodiesel pump, I can make 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 point to the scheme as a significant advantage in assisting improve their output.

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

"Having a plan like this assists us a lot. Our yields are great which suggests we can settle the cost of the pump slowly in little quantities, and have cash left over to pay the school costs."

Zaynagro's effort is still in its early stages, with few farmers having paid back the full expense of the pumps.

But such biofuel plans are appealing since they develop a circular economy by turning waste to biofuel for profit, said Sanjoy Sanyal, senior partner for Clean Energy Finance at the World Resources Institute.

The simpleness of the model - easy-to-use, robust innovation, ensured supply of biodiesel combined with a pay-as-you-go plan - could assist amaze rural Africa, he said.

"There is a mosaic of sustainable energy options on the planet. The key concern is testing concepts and techniques in a collaborative fashion," said Sanyal.

"Other cotton ginning factories in the area should try and learn from this experiment. Banks ought to start experimenting with loans to groups of farmers. International donors and investors 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, women's and LGBT+ rights, human trafficking, home rights and environment change. Visit http://news.trust.org)