Examination of Soil Sustainability Following Long-Term Sod Production.

Over 14,000 hectares of land are planted to sod in Ontario and although established turfgrass provides numerous environmental benefits, conventional harvesting of sod involves the removal of a layer of soil below the thatch. This can result in the permanent depletion of soil resources, deterioration of soil structure, reduction of organic matter and potentially increased susceptibility to soil erosion.  The objectives of our research were to determine if there are changes in soil quality parameters after a long history of sod production (> 30 years) that could lead to soil depletion and increased susceptibility for erosion. Eighty soil cores were collected to a 100 cm depth for comparison of profiles between fields with a long history of sod production versus those growing alternative crops.  Results indicate that the Ap horizon experienced a small reduction in fields with long-term sod production. Organic matter content of soils and water aggregate stability (WAS) were determined by LOI and wet sieving methods respectively. Soil organic matter and WAS were highest in fields that were sod covered (4.2% and 42.9% respectively) while fields with alternate crops and those that were bare had lower organic matter content. A positive correlation ( R² =0.49) was found between WAS and soil organic matter. Changes in the structure of humic (HA) and fulvic (HA) acids within the various fields were also measured. Our data indicate that the structure of FA and HA in all soils under sod production underwent changes when compared to alternate crops. Although none of these changes were strong enough to drastically deteriorate soil quality further investigation is needed to determine the effect of long-term sod production and soil removal on overall soil quality and to develop best management practices for reducing any potential negative impact.