By Nita Bhalla

KITUI, Kenya, June 6 (Thomson Reuters Foundation) - Kenyan farmer Abel Mutie Mathoka thought it should be a joke when he was informed he might irrigate his drought-hit crops more cheaply, easily and effectively utilizing a pump fuelled by cotton waste.

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

"But it works," he stated, strolling over to a nearby tree and plucking a big green pawpaw. "Irrigation with this biodiesel water pump has helped me get higher yields, particularly throughout dry spell durations."

Mathoka said 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 cheaper than regular diesel.

The biodiesel he is using is not simply good news for him - it is also great news for the world.

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

That implies that in addition to being cleaner and cheaper than fuel, it is more sustainable than other biofuels due to the fact that no extra land is required to produce it.

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

"Our biodiesel comes from squashing 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 utilizing it to power our cotton ginning factory in 2011. With increased production, we now use it for our trucks, offer it to the United Nations to run some of their buses - and also to local farmers for irrigation."

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

DRY RIVER BEDS

Climate modification 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 repeating dry spells are ruining crops and pastures and are starving animals - pressing millions of individuals in the Horn of Africa to the brink of extreme cravings.

The variety of Kenyans in need of food help in March rose by nearly 70 percent over a duration of 8 months to 1.1 million, mostly due to bad rains, according to federal government figures.

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

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

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

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

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

Villagers grumble of travelling longer distances - often more than 10 km (6 miles) with their donkeys packed with empty jerry cans in search of water.

Small-scale farmers, the majority of whom are dependent on rain-fed farming, discuss strategies to sell their goats to make ends meet if the harvest is poor.

BATTLING DROUGHT WITH BIODIESEL

But not all Kitui's farmers are fretted.

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

Neighbouring farmers band together to invest in the irrigation system - which consists of the biodiesel pump, 12 metres of pipelines and 10 litres of biodiesel - at expenses beginning with 32,000 shillings, depending upon the size of the pump.

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

Farmer Alex Babu Kitheka, 39, stated the biodiesel pump permitted him to water a bigger part of his one-acre plot, where he grows a variety of vegetables including 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 make 45,000 shillings," said Alex Babu Kitheka, standing near his plot in Ilangilo town, 40 km (25 miles) from Kitui town.

CIRCULAR ECONOMY

Other farmers indicate the scheme as a major advantage in assisting improve their output.

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

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

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

But such biofuel schemes are appealing because they develop 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 simplicity of the design - easy-to-use, robust technology, ensured supply of biodiesel integrated with a pay-as-you-go scheme - might help energize rural Africa, he said.

"There is a mosaic of sustainable energy alternatives worldwide. The crucial problem is checking ideas and approaches in a collaborative style," stated Sanyal.

"Other cotton ginning factories in the region need to attempt and gain from this experiment. Financial organizations ought to start try out loans to groups of farmers. International donors and investors need 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, property rights and environment modification. Visit http://news.trust.org)