Welcome to the circular world of organics. Food waste and other kinds of organic material embody an important aspect of the circular economy—the nutrient cycle. From rotten food to food scraps to yard waste, we break down how the nutrient cycle works and ways to manage organic waste in a way that prevents valuable nutrients from going to waste.
Organics & the Circular Economy
The circular economy has two primary loops—the technical loop and the nutrient cycling loop. Together, these two cycles cover all of the materials that we use every day.
The Nutrient Cycle
You may be familiar with the technical cycle, which is the part of the circular economy that includes recycling. This includes materials like metals, glass, and plastic, which can be recycled into new materials. The nutrient cycling loop, however, is a natural process rather than a mechanical one, where materials are broken down into their baseline nutrients, to be reused again and again. This Ellen MacArthur Foundation diagram illustrates the relationship between the technical and the nutrient cycles.
A great example of the nutrient cycle can be seen in a forest. Trees use energy from sunlight, water, and nutrients from the soil to grow leaves in the spring. In the fall, trees drop their leaves onto the ground. Over time, those leaves compost and put nutrients back into the soil, where the tree can reuse the nutrients to grow new leaves. This process happens over and over again, and valuable nutrients are never wasted. Nature provides the perfect model of a circular economy.
Benefits of the Nutrient Cycle
Putting food waste and other organic waste into a landfill or incinerator breaks the nutrient cycle because valuable ingredients for healthy soil go to waste. When incinerated or landfilled, the nutrients are removed from the natural system and cannot be used continuously.
A major sector of Indiana’s economy is industrial agriculture. Growing crops naturally removes critical nutrients from the soil, which need to be replaced in order to continue crop production. Traditional farming methods rely on synthetic, fossil fuel-based fertilizers to support the soil needs for crop production.
The critical nutrients in Indiana’s food waste is a valuable opportunity to manage food waste, reduce our reliance on expensive fertilizers, and preserve healthy soil for improved crop production.
By managing food waste and keeping food out of the trash, the nutrient cycle is maintained and the soil is strengthened. This also restores soil structure, supports microorganism diversity in the soil, reduces nutrient runoff, and improves water retention and drainage.
Ways to Reduce Food Waste
There are many different ways to reduce food waste, as shown in our food waste hierarchy diagram. And while all tools of food waste management are important, it’s best to start at the top of the pyramid and work your way down. Just like it’s important to reduce first before recycling, it’s most important to prevent food waste at the source and feed hungry people before composting.
[Insert food waste hierarchy graphic from website—Organics page]
Source Reduction by Buying Local
Buying food produced locally and in-season can help reduce food waste that happens before it reaches individual households. Because food waste happens at every step of the food system, fewer steps mean less overall food waste. For example, buying food directly from local farmers removes the need for transportation, distribution, and storage at stores. Food bought locally travels fewer steps along the chain, and therefore has less opportunities to be damaged or expire. Buying seasonal foods also helps reduce waste by eliminating excess produce that may all come ready at the same time.
Source Reduction in Cooking
Careful planning and creative cooking methods can help reduce food waste during preparation. When trying to reduce food waste at the household level, there are three categories to focus on: storage, preparation, and using leftovers.
Don’t forget about expiring food by designating a spot in the front of the refrigerator or pantry to highlight these items. Store fruits and veggies properly to increase their shelf life, and learn more about food expiration labels—most dates on food are not an indicator of food safety but a recommendation for the best flavor.
Plan meals carefully to determine exactly how many ingredients you need to avoid overbuying. Cook dishes that use the entire part of the plant, like soups that use broccoli stems or carrot-top pestos. Use bones and vegetable scraps to make broth for soups.
Get creative with ways to use leftover meals and ingredients. Store small portions in repurposed glass jars or ice cube trays in the freezer for future use. Designate a “leftover night” of the week, where your household eats the leftovers from the previous few days instead of cooking a new meal.
Source Reduction on Farms
Over a quarter of food produced in the United States never makes it off the farm. There are many reasons for this, including disease, pest, or weather outbreaks, lack of demand, and more. One way to reduce food waste on farms is through gleaning, a process which collects leftover food. Gleaning on farms can help capture produce with a lack of demand or even sort through damaged food from insects or weather to determine what is still edible. Gleaning organizations often work with local and regional food pantries, and their distribution networks to repurpose food to feed hungry people. Indiana has a number of gleaning organizations working to reduce food waste on farms.
Feeding Hungry People
Gleaning organizations also repurpose food leftover from restaurants and/or stores to feed the 725,000 hungry people in Indiana. Organizations like Gleaners in central Indiana collect and sort food from retailers and distribute it to food pantries across the state. Other organizations like Second Helpings repurpose leftover food from restaurants and commercial food operations into free meals for food-insecure individuals. Visit our Organics page for a list of Indiana food rescue organizations.
Despite best efforts, sometimes food goes bad and is no longer fit for human consumption. However, much of this food still has value as animal feed. At the industrial level, Indiana organizations like 101, inc. take expired or soon-to-expire foods like dairy, non-dairy milks, infant formula, and more and process them into pig feed. This process ensures that valuable nutrients do not go to waste while reducing the need for other types of feed production. At an individual level, local animals can be fed some kinds of food waste. Examples include donating pumpkins to local goat farmers after Halloween, making bird suet from leftover fat or grease, or feeding stale nuts to squirrels.
Anaerobic digestion is the process of breaking down organic waste using microorganisms, often at high temperatures. The process is similar to composting, but anaerobic digestion happens more quickly and doesn’t require oxygen, a critical ingredient in composting. Anaerobic digestion can handle a larger range of organic waste than composting, such as bones, oils, fats, meats, dairy, and even sewage. It also generates biogas—a renewable energy source that can be used to generate electricity or heat—and digestate. Digestate is sludge similar to finished compost that can be used to fertilize crops.
Industrial Uses: Land Application
In addition to compost, many types of organic and food waste can be used in land application, which is the process of applying waste to fields in place of fertilizer. One common type of land application is the use of manure in agriculture. Other types of waste that can be used in land application include silage, food by-products like whey from cheesemaking, and sludge from water treatment plants.
Industrial Uses: Non-food products
Some organic and food waste may not be edible, but can have other uses for making products. One example is wheat straw, which can be used to make bioplastics for travel mugs, water bottles, and more. *These are innovative strategies to divert waste, but they do not return valuable
Another common non-food product is biochar, a partially-burned organic material similar to charcoal. Biochar can be made from waste organic materials and has many uses, including fuel, soil application, animal feed, and even water filtration.
Closing the Loop
Food waste reduction is a valuable part of the circular economy, and it’s happening right here in Indiana. And because our economy is so dependent on agriculture, food management solutions like animal feed, gleaning, and composting have an even greater value. By reducing food waste, we can help end hunger in Indiana, feed our livestock industry, preserve the value of food, and create healthy soils for growing new crops.
To learn more about the different commodities, how they fit into the circular economy, and the organizations doing circular work in Indiana, make sure you subscribe to our newsletter and follow @CircularIndiana on social media!
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