For sod producers, there are management options that can affect the sod crop as well as the extent of nitrate contamination of groundwater. This project examined the management options that most affect the production of sod and that could impact groundwater quality from fertilization.

Groundwater quality sampling in Suffolk County, NY indicated agricultural land uses had much higher concentrations of nitrate in groundwater wells than other land use types. Of the agricultural sites monitored, wells under a sod production field had the highest level of nitrates. The drinking water source for the over one million people of Suffolk County is groundwater as well as groundwater also affects the quality of salt water estuaries of Long Island. Suffolk County government with the help of Cooperative Extension is developing plans to protect water quality from all agricultural producers including sod production. This project will provide the information needed to allow sod producers to produce a crop while minimizing the impact on groundwater quality.

To understand the role that sod production may play in nitrate contamination of groundwater, research studies were initiated in the fall 2005 on actual sod production fields in Suffolk County. We monitored the amount of nitrate movement under a sod crop to determine if the amount and source of nitrogen fertilizer would affect the production of sod and the movement of nitrate. These studies are being completed in 2008 and results will be provided to sod growers and policy makers on the role that sod may play in groundwater problems on Long Island and what management options are available to sod producers to protect groundwater quality.

Contrary to popular practice, we have found that a limited amount of nitrogen fertilization was needed to produce a sod crop, and as well as minimize the amount of nitrate movement into groundwater. Higher amount of fertilizer did little to produce a better sod crop, but resulted in much greater movement of nitrate into groundwater. We are still completing the project so there are no measurable impacts at this point in time

Cornell Cooperative Extension of Suffolk County