Carbon Sequestration and Photosynthesis in Newly Established Turfgrass Cover in Central Chile

Abstract

Core Ideas Soil organic C varied for 3 yr and four seasons for the five cool season turfgrass species (C3) and the two warm season turfgrass species (C4) when compared to bare soil. The effect of turfgrass species was detected in all of the seasons, where turfgrass coverage increased soil organic C over time, primarily at the 0‐ to 10‐cm soil depth. Carbon dioxide fixation rate can be an adequate indicator of carbon sequestration potential in a short‐term period for turfgrass species. This study showed that Cynodon dactylon L. and Festuca arundinacea Schreb. were the most promising species to increase C sequestration and to better use the irrigation water in central Chile. Growth of the urban population in central Chile may have contributed to increased CO2 emissions, thus information regarding the role of turfgrass in public spaces and its ability to sequester CO2 would be valuable. The objectives of this study were to assess and compare the magnitude of C sequestration of seven newly established turfgrass species to bare soil using seasonal organic C stocks measurements aboveground (aboveground organic carbon [AOC]) and belowground (soil organic carbon [SOC]) and to associate these data with turfgrass seasonal photosynthetic behavior. Festuca arundinacea Schreb, Festuca rubra L. ssp. rubra, Cynodon dactylon L., Cynodon dactylon L. × Cynodon transvaalensis Burtt Davy, Poa pratensis L., P. trivialis L., and Lolium perenne L., and areas with bare soil were established during 2010. Soil samples from 10, 20, and 30 cm were collected over 2 yr. Cuttings from each turfgrass species were also collected seasonally after reaching higher than the 4 cm cutting height. The SOC and AOC were assessed using the Modified Mebius method. The CO2 assimilation rate, stomatal conductance and photosynthetic water use efficiency were measured seasonally over 2 yr using an infrared gas analyzer. Turfgrass species with high photosynthetic activity during the summer, such as C. dactylon and F. arundinacea ‘Bingo’, resulted in a high total SOC of 2.4 t SOC ha−1 and 2.7 t SOC ha−1, respectively, when compared with bare soil (0.9 t SOC ha−1) at the end of the study.