Assessing Soil Carbon Sequestration in Turfgrass Systems Using Long‐Term Soil Testing Data

Abstract

As part of the urbanization process, an increasing percentage of land throughout the USA is being converted into turfgrass. Because of high productivity and lack of soil disturbance, turfgrass may be making substantial contributions to sequester atmospheric C. To determine the rate and capacity of soil C sequestration, we compiled historic soil‐testing data from parts of 15 golf courses that were near metropolitan Denver and Fort Collins, CO, and one golf course near Saratoga, WY. In addition, we compiled a total of about 690 data sets on previous land use, soil texture, grass species and type, fertilization rate, irrigation, and other management practices. The oldest golf course was 45 yr old in 2000, and the newest golf course was 1.5 yr old. Nonlinear regression analysis of compiled historic data indicated a strong pattern of soil organic matter (SOM) response to decades of turfgrass culture. Total C sequestration continued for up to about 31 yr in fairways and 45 yr in putting greens. However, the most rapid increase occurred during the first 25 to 30 yr after turfgrass establishment, at average rates approaching 0.9 and 1.0 t ha −1 yr −1 for fairways and putting greens, respectively. Our study also found that past land use imparted a strong control of SOM baseline; fairways converted from agricultural lands exhibited 24% lower SOM than fairways converted from native grasslands. We concluded that C sequestration in turf soils occurs at a significant rate that is comparable to the rate of C sequestration reported for USA land that has been placed in the Conservation Reserve Program.