These affordable biodigesters make smallholder farms more autonomous and resilient.
By Sam Golden
Smallholder farmers—those cultivating less than two hectares of land—produce a third of the world's food. Yet, despite their crucial role in global food security, most live below the poverty line.
This financial strain makes access to reliable, affordable energy a constant challenge. Without electricity or modern energy infrastructure, many farmers rely on environmentally harmful fuels. Firewood and charcoal are linked to deforestation and air pollution, whilst the carbon emissions from diesel, coal and other fossil fuels are driving climate change.
At the same time, smallholder farmers also struggle with soil health and long-term crop yields. Poor soil conditions often push them toward synthetic fertilizers, which are expensive and deplete essential nutrients over time. This creates a vicious cycle—declining soil fertility reduces productivity, forcing farmers to rely even more on costly fertilizers that further degrade their land.
For more on the problems associated with synthetic fertilisers, see Sam Golden’s articles on Wildfarmed and Farmers Footprint.
Adding to these challenges is the issue of agricultural waste. Farms worldwide generate over 1.3 billion tons of organic waste each year. Instead of being used as the valuable resource that it is, this farm waste is often left to decompose. As it decomposes, it releases methane—a potent greenhouse gas that significantly contributes to global warming.
Together, these interconnected problems—energy poverty, soil degradation, and waste mismanagement—trap smallholder farmers in a cycle of financial hardship and environmental decline. Without sustainable solutions, the one-third of global food production that they are responsible for is in danger. Food insecurity is already an major challenge, but this could be just the tip of the iceberg.
Fortunately, Mexican company Sistema.bio has developed a promising solution for smallholder farmers: affordable and accessible biodigesters.
Their biodigesters process animal manure and other farm waste to produce biogas—a clean, renewable energy source. Farmers can use this biogas for cooking, heating water, and other household or farm activities, reducing their reliance on expensive and polluting fuels like firewood and diesel.
In addition to generating energy, the biodigesters produce a nutrient-rich organic fertilizer known as “bioslurry”. Unlike synthetic fertilizers, which degrade soil over time, bioslurry replenishes essential nutrients and supports natural microbial activity, helping farmers grow healthier crops while lowering their dependence on costly chemical fertilizers.
One of Sistema.bio’s strengths is the adaptability of its technology. The biodigesters are designed to function in diverse climates and with various types of organic waste, making them suitable for both small family farms and larger agricultural operations. To ensure long-term success, the company also provides training, customer support, and financing options, making it easier for farmers to invest in and maintain their systems. This allows Sistema.bio offer a 20 year guarantee on their biodigesters.
Sistema.bio is an inspiring success story. More than 114,000 of its biodigesters have been installed worldwide, providing access to clean, renewable energy for over half a million people. Additionally, the biofertilizer produced by the system is now enriching over 1.8 million hectares of farmland every year.
The company estimates that if just 10% of the world’s smallholder farmers adopted their technology, it could prevent the equivalent of over 1 billion tons of emissions annually by reducing methane emissions from crop waste and decreasing farmers’ reliance on polluting energy sources.
One area that needs further attention is the environmental cost of manufacturing the biodigesters themselves. The materials and energy involved in producing and distributing thousands of units could offset some of the climate benefits if not managed carefully. Exploring ways to build digesters from recycled or lower-impact materials would strengthen the long-term sustainability of the model.
What makes this solution especially important is its role in strengthening the resilience of smallholder farmers. In recent decades, the vulnerable position that they have found themselves in has paved the way for large, extractive agribusinesses to buy up land, replace diverse local crops with monocultures, and further degrade ecosystems through intensive chemical use.
By giving smallholders the tools to remain productive, independent, and economically viable, biodigesters act as a quiet form of resistance against this consolidation of power. They help preserve rural livelihoods, protect community food systems, and keep land in the hands of those who tend it with long-term care—not just short-term profit. This is not just about reducing emissions or producing cheaper energy—it's about ensuring that the smallholder farmers remain a central part of a more just, sustainable, and resilient global food system.