Carbon Dioxide Flux from Bermudagrass Turf as Affected by Nitrogen Rate

• Published in: Agronomy journal 2016-05, Vol.108 (3), p.1000-1006
• Main Authors: Hamido, Said A., Wood, C. Wesley, Guertal, Elizabeth A.
• Format: Article
• Language: English
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2015.0498

Increasing carbon dioxide (CO2) concentrations have contributed to global climate change. Atmospheric CO2 concentration has increased by ≈43%, from 280 ppmv in 1850 to 400 ppmv in 2015. This increase is expected to alter the distribution of C among the atmosphere, vegetation, and soils. Despite its large‐scale presence in the urban ecosystem, the role of turfgrasses in C cycling has received limited attention, and studies with warm‐season turfgrasses are lacking. The objective of this study was to estimate CO2 flux from soil as affected by N applied to bermudagrass [Cynodon dactylon (L.) Pers. C. transvaalensis Burtt Davy]. The study was initiated in March 2012 on 8‐yr‐old Tifway hybrid bermudagrass plots located at the Auburn University Turfgrass Research Unit on a Marvyn loamy (fine‐loamy, kaolinitic, thermic Typic Kanhapludult) sand soil. The experimental design was a randomized complete block with four N rates of 24, 49, 98, and 196 kg N ha−1 yr−1 that were replicated three times. Carbon dioxide flux was measured weekly for 95 wk using an automated soil CO2 flux system (LiCor LI‐8100A, LICOR, Inc., Lincoln, NE). Soil temperature and moisture were also determined during CO2 flux measurements. Results showed strong correlation between CO2 flux and N rate (r2 = 0.99∗∗). Accumulated CO2 flux increased by 35%, from 107 to 144 Mg ha−1 as N rate increased from 24 to 196 kg N ha−1, respectively. Data suggest that a lower N application rate may be a better choice for mitigation of CO2 emissions under bermudagrass management. Core Ideas Averaged daily fluxes of CO2 were significantly (r2 = 0.99∗∗) correlated with N rate. Lower N application rate may be a better choice for mitigation of CO2 emissions under bermudagrass management. Increasing soil temperature has increased CO2 fluxes.