Utilizing Compost to Boost Crop Productivity

International Compost Awareness Week is May 6-12 this year. This educational initiative, promoted by the Composting Council Research and Education Foundation, was started in Canada in 1995, and has continued to grow in popularity as communities, businesses, municipalities, schools, and organizations celebrate the benefits of compost and composting. But perhaps the most important people involved in composting are the farmers who produce compost to grow the food we eat.

Compost can be produced and used on the farm as a valuable soil amendment, capable of providing not only a source of slow-release nutrients for crops, but also a way to improve soil structure, increase soil moisture-holding capacity, promote biological activity to enhance plant nutrient availability, suppress weeds, and even help combat some plant diseases.

Although creating on-farm compost can take a lot of time and energy, it can be worth a farmer’s effort, if it keeps soil fertility costs down. One way many farmers produce enough compost to meet their fertility needs is to collect waste products generated by their surrounding community. If a system for collection and transportation can be developed, and non-compostable waste can be excluded, farmers can use waste from grocery stores, restaurants, food processing facilities, breweries, seafood markets, horse stables, dairy operations, and chipped trees collected by power line crews as they clear encroaching tree canopies.

Once a farmer has secured sources for compostable materials, next comes the step of mixing the materials to generate heat, up to 140 degrees Fahrenheit. Fortunately for the farmer, microorganisms do most of the work in the decomposition process. But it is the farmer’s responsibility to provide enough –  and the proper balance of – air, moisture, and nitrogen and carbon-rich food to fuel the aerobic microbial oxidation process. The volume needed to generate favorable composting conditions can be anywhere from about one cubic yard up to 40 cubic yards, depending on these factors.

This is why farmers, who depend on compost to supply a majority of their crops’ nutrient needs, often rely on a dump trailer and tractor front-end loader to move compost ingredients, turn compost piles, and spread the finished product on row beds. With experience, farmers learn the correct ratio of ingredients, proper volume and porosity of their piles, when temperatures plateau and piles need to be turned, and when the compost is finished and ready for use.

High quality finished compost typically has an organic matter content of about 50 percent, a carbon to nitrogen ratio of around 20:1, near neutral pH, low soluble salts, and is free of weed seeds and plant phytotoxins. Compost nutrient content by volume is relatively low, and availability can vary greatly depending on soil and climatic conditions, so it is important for the farmer to monitor crop nutrient requirements and use additional amendments as needed. But when compost is used as a long-term strategy for improving soil health and building soil organic matter, its benefits can be appreciated for generations.

Interested in learning more about compost? Leon County Extension is hosting a “Got Compost?” workshop May 8, 6:00 p.m. to 8:00 p.m. EST, in celebration of International Compost Awareness Week. This workshop is tailored more for home-composters, but will also touch upon ways to up-scale compost production and will discuss small farm compost production strategies. To find out more and to register, visit the Leon County Extension Eventbrite Page.

Additionally, the Red Hills Small Farm Alliance – a non-profit organization of over 50 farmers within a 100-mile radius of Tallahassee – is promoting International Compost Awareness Week on its website and Facebook page. If you utilize compost on your farm, upload a short compost video to the Red Hills Small Farm Alliance Facebook Page for a chance to win a $50 gift certificate to the Red Hills Online Market.