What if the materials we often consider waste could become the foundation for growing nutritious food?

Across Nigeria, tonnes of agricultural by-products are generated daily. Rice mills produce rice bran, sawmills generate mountains of sawdust, poultry farms struggle with waste management, and fish farms continuously discharge nutrient-rich water. In many cases, these materials are treated as environmental burdens and disposed of with little thought to their potential value.

Yet within these waste streams lies an opportunity to address some of our most pressing challenges: food insecurity, environmental pollution, rising agricultural input costs, and climate change.

This opportunity is at the heart of the City Waste for Increased Food and Wealth (CiWaCiWe) project.

Rethinking Waste as a Resource

Traditional agricultural systems often operate linearly. Resources are extracted, used, and discarded. This approach creates waste while increasing pressure on natural resources and the environment.

CiWaCiWe is helping to demonstrate a different model—one based on circular agriculture.

Instead of treating agricultural by-products as waste, the project explores how they can be transformed into productive inputs for food production.

One of the innovative approaches being tested involves using rice bran and sawdust as planting substrates for crop cultivation.

Building Growing Media from Agricultural By-Products

Healthy crop production begins with a suitable growing medium. Conventional farming depends on soil, while many hydroponic systems rely on imported substrates that can be expensive and difficult to access.

Through the CiWaCiWe project, rice bran and sawdust are being evaluated as locally available alternatives.

These materials are abundant in many Nigerian communities and are often underutilized despite their potential value in crop production systems.

However, using them effectively requires more than simply placing seeds into the materials. The substrates must first be enriched with nutrients capable of supporting healthy plant growth.

Harnessing the Power of Poultry Waste and Aquaculture Water

To improve the nutrient content of the substrates, rice bran and sawdust are cured using poultry waste and aquaculture water.

Poultry waste contains valuable nutrients such as nitrogen, phosphorus, and potassium that are essential for plant development. Aquaculture water, which is often discharged as waste from fish farming operations, contains dissolved nutrients generated through fish production activities.

By combining these resources, the project creates nutrient-enriched growing substrates capable of supporting vegetable production while reducing dependence on synthetic fertilizers.

This approach creates a practical link between crop farming, poultry production, and aquaculture, allowing resources to circulate within the agricultural system rather than being discarded.

Environmental Benefits

The environmental implications are significant.

Rice bran and sawdust that might otherwise be burned, dumped, or left to decompose are repurposed into productive agricultural inputs.

Poultry waste is diverted from disposal pathways that can contribute to environmental contamination.

Aquaculture water is utilized as a resource rather than discharged into surrounding ecosystems.

Together, these practices contribute to improved waste management, reduced pollution, and more efficient resource utilization.

Supporting Climate-Smart Agriculture

As climate change continues to challenge agricultural production, farmers must find ways to produce more food using fewer resources.

The use of locally available waste-derived substrates supports climate-smart agriculture by reducing reliance on external inputs, improving resource efficiency, and promoting sustainable nutrient cycling.

The approach also contributes to lower production costs, making innovative farming systems more accessible to young people, women, and smallholder farmers.

Creating a Circular Food System

Perhaps the most exciting aspect of this innovation is what it represents.

Rice bran from rice processing, sawdust from timber operations, poultry waste from chicken production, and nutrient-rich water from fish farming are all being transformed into resources that support food production.

What was once considered waste becomes part of a productive cycle that generates food, income, and environmental benefits.

This is the essence of circular agriculture.

The Future of Sustainable Farming

The City Waste for Increased Food and Wealth (CiWaCiWe) project is demonstrating that solutions to food insecurity and environmental challenges do not always require expensive technologies or imported inputs.

Sometimes, the answers already exist within our communities—in the materials we discard every day.

By transforming rice bran, sawdust, poultry waste, and aquaculture water into productive growing systems, CiWaCiWe is helping to build a future where agriculture is more sustainable, resource-efficient, and resilient.

The lesson is simple: waste is only waste when we fail to recognize its value.