University of Colorado Boulder
IN-4: Innovation 4

Over the last three years, CU has transitioned away from synthetic-pesticide and synthetic-fertilizer use on campus turf. Instead, CU has implemented a health-based turf management system using organic fertilizers, hand removal of weeds, and bioassay of soil borings across campus to measure soil microorganism types and populations at varying depths. The key to the health-based system is building and maintaining appropriate levels of soil microorganisms in all turf areas. Using Compost Tea to help inoculate the soils with these microorganisms was seen as a possible technology to accomplish this.

With a desire to use Compost Tea for the entire landscape we needed to find a way to apply the product without the use of large boom sprayers as is the normal application method. We worked to create a method of brewing and injecting the Compost Tea extract directly into the irrigation system thus allowing an application to all of the turfgrass and landscape beds in one application without any impact to the campus users. This application method was extremely challenging based on calculation of rates, survival rates of the microorganisms, sprinkler and valve impacts of the product. It took many months of trial and error to determine how to set up the irrigation system to allow proper "priming" of the system to make sure that every zone had Compost Tea in the water when the station turned on.

Based on current technologies and knowledge of other Compost Tea users no other large scale institution has put forth the amount of effort and financial backing to allow for the creation of this innovative application method. Indeed, only a few campuses have moved to a health-based turf management system, and none in Colorado.

The use of Compost Tea has aided in our ability to provide a healthy soil profile which is more conducive to turfgrass health and allows us to maintain a very dense turf canopy which helps prevent the ability for weeds to encroach. We have been doing soil Bio-Assay tests every year since we began Compost Tea injections. We have found that the overall biological life within the soil profile has increased and has allowed us to reduce the use of our organic fertilizer because the soil is more adept at processing organic matter and thus producing plant available nutrients.

We are also in the early phases of a dedicated research project to help determine scientifically the effectiveness of this approach and this will help us continue to fine tune the Compost Tea program to achieve the best possible results of the new technology.