Athletic field managers often seek an organic source for humus to combat compaction, enhance water holding, and counter low cation exchange capacities (CEC) in athletic field soils. Compost is essential to growing good grass (and keeping your job).
Many good groundspeople turn to compost for aid and comfort because it provides a concentrated source of humus (some composts are 90% or more organic matter), have a good water holding capability, and have 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 given that a ¼” topdressing produces noticeable improvement in grass color.
Compost should not be left as a layer on soil or existing grass, but incorporated via aeration. This win-win situation greatly improves soils and makes the groundsman look good.
The term “compost” is similar to the term “love” – it means many things to different people. Bad compost and bad love can really hurt!
Compost is complete when there is no discernible structure of the original organic material left in the product and when the pile does not generate heat when turned to induce more oxygen in it. It should not be used until it completes the composting process. Incomplete compost will show pieces of straw, manure, leaves or whatever it was made of. If the material is steaming it will not be beneficial because it is still drawing nitrogen from its environment rather that giving it.
Compost producers are plagued with the possibility of glass and plastic in the compost. There are some applications where glass or plastic pieces are of no consequence, such as mixing into soil. They do matter 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 groundsperson must check these issues or expect to pay consequences in terms of costs and image. Both will be negative!
It is incumbent upon the user to gain the benefits of using compost without encountering the problems. This means that the compost vendor must understand what the groundsperson wants and what he/she is going to use the compost for. The understanding must include the method and criteria for rejecting a load of compost and the consequences of foreign objects in the material.
All of us want to produce a good product; compost is a great aid if used correctly and if it is of high quality.