ABSTRACT
Turfgrass cover in the U.S. is expanding because of increasing
urbanization and the addition of approximately 675,000 ha of residential
property every year. Despite its large-scale presence in the urban ecosystem,
the role of turfgrasses in carbon (C) cycling in home lawns in southeastern
U.S. soils has not been documented, and studies with warm-season turf grasses
are lacking. The objective of this study was to estimate carbon (C) sequestration
in soil as affected by turfgrass species, including: bermudagrass (Cynodon dactylon (L.) Pers. × C.
transvaalensis Burtt Davy), centipede grass (Erecholmoa ophroides (Munroe) Hack.), and zoysiagrass (Zoysia spp.). The study was initiated in
the winter of 2012 and conducted for two years on a loamy sand (fine-loamy,
kaolinitic, thermic Typic Kanhapludult) soil. Eighteen lawns were sampled twice
per year: six lawns of each grass species, with the harvested grasses separated
into stems, above ground biomass (verdure) + thatch, and belowground roots.
Soil samples (0 - 5, 5 - 10, and 10 - 20 cm) were also collected. Total C
concentration was determined on finely ground-dried samples by combustion. Turfgrass
species, season and years of sampling were all significantly (P ≤ 0.05) affected by C
sequestration. Zoysiagrass had the highest mean levels of sequestered
C, with a value of 5.54 ± 0.21, compared to 2.09 ± 0.11 and 4.23 ± 0.14 Mg·ha-1·yr-1 under bermudagrass and centipedegrass at the end of the study, respectively.
This work indicates that turfgrass home lawns may be an important contribution
to the global carbon sequestration level.