By Michelle Cohan
News of the drought across Africa in the early 1980s troubled Father Godfrey Nzamujo, then an expatriate priest and professor at the University of California, Irvine.
"People were dying of starvation. I couldn't stand it," Nzamujo told CNN.
Equipped with a microbiology PhD and his faith, he travelled back to Africa in search of a solution.
There, he found a continent ecologically rich, diverse and capable of producing food.
He believes drought wasn't the only reason for widespread hunger, and that sustainability had been left out of the equation.
Nzamujo began devising a "zero waste" agriculture system that would not only increase food security, but also help the environment and create jobs.
In 1985, he traded in his professor post for gardening gloves and started his sustainable farm "Songhai" in the West African country of Benin.
At the core of the idea of sustainable agriculture is designing farms that mimic the way natural ecosystems work.
"One really important piece of that is structuring farms to persist without external inputs like fossil fuels or toxic chemicals," said Liz Carlisle, an assistant professor in Environmental Studies at the University of California, Santa Barbara.
Those can create problems that degrade both the food system and the surrounding environment, she said.
Zero waste agriculture, a type of sustainable farming, takes these principles even further by introducing a regenerative loop, where waste in one area produces feed, fuel or nutrients for another.
"The output of one area, like the livestock production, would feed into either energy production or fertilizer for crops," explained Ronnie Brathwaite, a senior agriculture officer at the UN Food and Agriculture Organization. "The crop residues will be used in either energy production or livestock feeding, or even making other products."
"Zero waste" is a buzzword today with the spotlight on climate change. However, this type of farming is not new.
It was in place globally for millennia, until farms, especially in developing countries, moved toward synthetic fertilizer use and single crop production during the Green Revolution of the 1950s, according to Brathwaite.
During this period, growing populations generated a need to intensify the food supply quickly. Industrial agriculture created high yields, but it came with a high price, including large amounts of waste from crop production and livestock, Brathwaite explained.
"What was not taken into account was the impact on the environment and the very resources that support it, like soil and water," he said.
Wanting to restore synergy to farms in Africa, Nzamujo started his sustainable farming mission on a small plot of land given to him by the government of Benin.
In addition to providing organic produce locally, Songhai employs 300 people daily. They harvest crops, tend to animals, oversee composting, or service the biogas digester -- which turns chicken excrement into fuel.
Nzamujo lives on the farm and constantly updates his techniques. He credits his degrees in science and engineering for Songhai's success. But he also thanks his spiritual and cultural roots, and his father -- a driving force in his life who encouraged him to pursue his studies to the highest degree and to use Songhai to share his knowledge.
Songhai has several "eco-literacy" development programs. They range from 18-month training courses for farmer-entrepreneurs, to shorter stays to learn techniques like irrigation. People come from all over the world to study Nzamujo's methods.
Father Godfrey Nzamujo educates a group of people on his zero waste farm in Benin.
After seeing success on his first zero waste farm, he expanded throughout Benin and western Africa.
Today, the Songhai model is implemented across the continent, including in Nigeria, Uganda, Sierra Leone and Liberia. Nzamujo says they've trained more than 7,000 farmer-entrepreneurs and more than 30,000 people in total since it began.
It's not always easy to get started in sustainable farming. Beyond the educational investment, local policies and regulations also have to support this type of farming. Not every country allows crops and livestock to be grown together.
Many countries originally rejected Nzamujo's farm plans before Benin granted him some land.
Carlisle believes a key part in fostering the sustainable agriculture movement is decoupling the public sector from extractive agricultural models.
"There is a whole support system around industrial agriculture because it's been subsidized by national governments," she said.
However, Carlisle notes institutions are being built to support sustainable farmers.
Increasing food security
With more than 820 million people facing hunger globally, according to the UN, coupled with a rapidly increasing population, comes the need for even more food.
If there was a shift toward more sustainable farming practices, could it keep up with the demand?
Some research has shown this model, when implemented correctly, has the potential to produce almost as much as conventional farming. Both the UN and independent scientists have called for a paradigm change away from industrial agriculture to sustainable practices in order to help our planet and the food system.
"With zero waste farming, I think we're in a better position to satisfy the needs of the globe," Brathwaite said. "We can continue to produce similar levels of food to feed a growing population, and we have the advantage of reduction in wastage."
Nzamujo believes zero waste agriculture is now steadily tackling the issues he set out to defeat three decades ago: hunger, unemployment and environmental degradation. And he wants to see it go further.
"Yes, it is a revolution. But it's a revolution that is not them against us," he said. "It is a revolution that is inviting every people to a new way of seeing things.