CARBON CONCENTRATION IN SHOOTS AND ROOTS OF DIFFERENT GRASS SPECIES IN NUEVO LEON, MEXICO

In Mexico, studies on the evaluation of the carbon concentration coefficient in grasses are of great importance, but there is no information about it. In this study, the concentration of C in shoots and roots of 21 grass species was determined. The study was carried out during April and May 2018 in the municipalities of Linares and Montemorelos, Nuevo Leon, Mexico. A total of 378 samples was analyzed from 21 species, three sites per species, and two components per site; the measurements were made in triplicate. The concentration of C was obtained with the Solids TOC Analyzer. The average C concentration in the species ranged from 32.5% in Paspalum notatum Flugge to 39.9 % in Setaria viridis (L.) P. Beauv., with an overall average of 36.4 %. The concentration of C in the root component of all the species was 36.0 % and 36.9 % in the shoot. Pennisetum ciliare (L.) Link showed the highest C concentration in the shoot (41.9 %), and P. notatum displayed the lowest value (33.22 %). The average percentages of root C content among the species ranged from 31.8 % in P. notatum to 39.8 % in Cynodon plectostachyus (K. Schumann.) Pilg. An overestimation of the carbon sequestered in grasses results from using a generalized value for total carbon concentration.