Turfgrass and the Soil Environment
The periodic sloughing-off of grass roots, stems and leaves associated with the annual growth cycle of cool season grasses contributes large amounts of organic matter to the soil over the years. It is a known fact that soil organic matter additions are among the most important soil-improving practices. This is not only true for lawns but gardens and trees as well. In time, even unimproved, compacted soils over which a lawn has been established will benefit from this natural organic matter addition.
The soil structure improvement and humus development associated with these organic matter additions also contributes to improved water infiltration, greater rooting depth allowing for an expanded root zone with increased access to soil water and nutrient reserves, improved microbial activity and, ultimately -- a healthier, more dense, vigorous lawn.
The turfgrass root zone is an area of high soil microorganism activity. Because of this, many of the commonly used turfgrass pesticides, once in contact with the soil, are readily degraded and broken down into the basic elements. With this enhanced potential for breaking down soil contaminants such as pesticides, there is less opportunity for these materials to leach through the soil and affect groundwater supplies or be carried off-site in runoff water and affect surface water resources.