Will composting improve nutrient cycling on my pastures?
Answer: Adding good compost or compost tea to your pastures in place of inorganic fertilizers is a good way to improve nutrient cycling. Compost and teas derived from it inoculate the soil, augmenting the initial microbial populations. As many graziers have experienced, compost applications can result in immediate production responses that are sustained for three or more years. How many applications are needed and how long they last is a function of how well your soil is functioning biologically. At Montana Highland Lamb, for example, Dave Scott tries to cover each acre once every three years. On areas of the farm that have poorer soil, he has observed that compost applications increase grass production.
In a study conducted on California grasslands, a single application of compost to grasslands increased carbon storage 25 to 70%, and that is not including the carbon that was in the compost that was applied (White, 2014). And while carbon dioxide respiration increased, as well, increases in plant production offset the increase in respiration, meaning carbon was being added to the soil for the three years of the study after the initial single application of the compost, with no sign of stopping once the study was completed. The increase in carbon storage can likely be attributed to an improvement in plant productivity: plants were able to pump more carbon into the soil than they were before compost was applied.
Compost inoculants are also a great tool to increase soil fungi. Creating a fungal-dominated compost or tea on a large scale is not as easy as producing a bacterially dominated compost, but it is possible.
There are other ways to improve nutrient cycling, too, and these methods are outlined in the ATTRA publication Nutrient Cycling in Pastures. The publication looks at the pathways and drivers that move nutrients into, out of, and within pasture systems. It attempts to provide a clear, holistic understanding of how nutrients cycle through pastures and what the producer can do to enhance the processes to create productive, regenerative, and resilient farm and ranch systems.
Also check out the Livestock and Pasture section of the ATTRA website, where you’ll find a host of useful resources, including publications, calculators, videos, and more.
White, Courtney. 2014. Grass, Soil, Hope. Chelsea Green Publishing, White River Junction, VT.