Utilizing Closed-Loop Agriculture: Farming Without Waste

Recycling Resources to Build Healthier Farms and a More Sustainable Future

Closed-loop agriculture is a sustainable farming approach that keeps valuable resources in continuous use by recycling nutrients, reusing water, and integrating livestock with crop production. Organic materials such as crop leftovers and animal manure are transformed into nutrient-rich compost, while rainwater and irrigation runoff are captured and reused to reduce waste. By creating a self-sustaining cycle, closed-loop agriculture improves soil health, conserves water, lowers dependence on chemical fertilizers, and helps farmers reduce operating costs while protecting the environment.

Closed-loop agriculture also supports long-term farm resilience by creating a more efficient and balanced ecosystem. By connecting crop production, livestock management, and resource recovery, farms can reduce waste while generating additional value from materials that were once discarded. Practices such as composting, anaerobic digestion, and water reclamation help return essential nutrients to the soil, improve productivity, and create a more sustainable approach to food production. This regenerative model allows farmers to build healthier operations that are better prepared for changing environmental conditions while contributing to a cleaner, more sustainable future.

Step 1

Collection

The process begins by collecting two primary types of organic waste from sources throughout the Midwest—materials that would otherwise end up in landfills. One source is food-grade byproducts generated by food manufacturers, grocery stores, and other commercial businesses. The second is manure collected from farms across the region.

Once the materials arrive, a portion of the food byproducts that are suitable for livestock feed is diverted to the farm’s animals. The remaining food waste, along with the manure, is blended and fed into the anaerobic digestion system. Inside the digester, naturally occurring microorganisms break down the organic material in an oxygen-free environment, producing renewable biogas and nutrient-rich digestate. This process diverts valuable organic waste from landfills while creating clean energy and useful agricultural byproducts.

Step 2

The Biological Process

Anaerobic digestion occurs in four biological stages that work together to break down organic waste. The process begins with hydrolysis, where bacteria break down complex organic materials, such as carbohydrates, into simpler compounds that other microorganisms can use. During acidogenesis, these simple compounds are converted into carbon dioxide, hydrogen, ammonia, and organic acids. Next, acetogenesis transforms the organic acids into acetic acid while producing additional hydrogen, ammonia, and carbon dioxide. In the final stage, methanogenesis, specialized microorganisms called methanogens convert these compounds into methane and carbon dioxide, creating renewable biogas that can be captured and used as a sustainable energy source.

Step 3

Harnessing Biogas for Clean Energy Production

The renewable biogas produced during the anaerobic digestion process is converted into clean energy and delivered through two different pathways. A portion of the biogas is sent to the engine room, where it fuels a series of generators that produce renewable electricity for the Northern Indiana Public Service Company (NIPSCO).

The remaining biogas is upgraded into renewable natural gas (RNG) and injected into NIPSCO’s natural gas pipeline system. By producing both renewable electricity and pipeline-quality natural gas, we farm maximize the value of organic waste while supporting a cleaner, more sustainable energy future.

Step 4

Turning Digestate into Valuable Fertilizer

After the anaerobic digestion process is complete, the nutrient-rich digestate, known as BioFluent, is processed through a mechanical separation system. This process creates two valuable fertilizer products: a high-quality natural crop fertilizer marketed to regional farms under the BioFluent name, and a certified organic compost fertilizer suitable for agricultural and landscaping applications.

The remaining liquid is not wasted. Instead, it is recirculated back into the anaerobic digestion system, where it is used to dilute incoming organic materials before they enter the digester. By reusing this water within the process, the system minimizes waste, conserves resources, and helps maintain efficient operating conditions while producing renewable energy and beneficial agricultural products.