Athletic field managers often need an organic source for humus to mitigate compaction problems, water holding needs, low cation exchange capacities (CEC), etc., in athletic field soils. Satisfying these needs is important for good grass growth.
Many good grounds managers turn to compost for aid because it provides a concentrated source of humus (some compost are 90% or more organic matter), has a good water holding capability, and has a high CEC. These traits make the green grass healthier and other fertilizers more efficient.
Compost has been found to have a point of diminishing returns in soil application when the compost begins to approach 1/3 by volume in the soil. This is a significant amount of compost. An application by topdresser of ¼” is noticeable in grass color and a maximum of ½” is excellent. The compost should not be left as a layer on the soil or existing grass, but incorporated via aeration. This win-win situation greatly improves soils and makes grass healthier.
CAUTION: THE USE OF PREMATURE COMPOST IS DETRIMENTAL TO YOUR FIELD’S HEALTH.
The compost process is complete when there is no structure of the original organic material left in the product and when the pile does not generate heat when turned, incorporating more oxygen into it. Thus, incomplete compost will show pieces of straw, manures, leaves or whatever it was made of. The material may be steaming-it will not be beneficial if used in that state because it is still drawing nitrogen from its environment and not giving it to the environment (grass roots, etc.). It should not be used until it completes the composting process.
Compost producers are plagued with the possibility of glass and plastic in the compost. Either of these poses a serious problem when the compost is topdressed; players cannot be exposed to glass shards for safety reasons and plastic is definitely unsightly and expensive to retrieve. The grounds manager must be vigilant to prevent these contaminations.
Different applications of compost may require a finer screening of the product. For instance, compost to be used in a topdresser will require a smaller particle size than compost
for bulk application.
It is incumbent upon the grounds manager to gain the benefits of using compost without incurring the problems. Careful selection of compost supplier, material inspection, and knowledge of product use are key to a positive outcome.
Proper use of quality compost is a great aid in producing healthy fields.
Information provided by Alpine Services, Gaithersburg, MD