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CO 2 fertilization does not affect biomass production and nutritive value of a C 4 tropical grass in short timeframe
Author(s) -
Abdalla Filho Adibe Luiz,
Lima Paulo de Mello Tavares,
Sakita Gabriel Zanuto,
Silva Tairon Pannunzio Dias e,
Costa Wilian dos Santos,
Ghini Raquel,
Abdalla Adibe Luiz,
Piccolo Marisa de Cássia
Publication year - 2019
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12443
Subject(s) - forage , dry matter , brachiaria , ruminant , biomass (ecology) , carbon dioxide , pennisetum purpureum , organic matter , agronomy , zoology , chemical composition , lignin , nitrogen , sowing , chemistry , carbon dioxide in earth's atmosphere , biology , crop , botany , organic chemistry
Increased atmospheric carbon dioxide (CO 2 ) is a consequence of recent anthropogenic environmental changes, and few studies have evaluated its effects on tropical grasses used in Brazilian pastures, the main feed source for major part of ruminant livestock. This study evaluated forage production, chemical composition, in vitro total gas production and organic matter degradability of Brachiaria brizantha under contrasting CO 2 atmospheric conditions in a free air carbon dioxide enrichment (FACE) facility. The forage plants were sown in each of the 12 octagonal rings of the FACE facility: six under ambient atmospheric CO 2 concentration of approximately 390 μmol/mol, hereafter referred to as control (CON) plots, and other six rings enriched with pure CO 2 flux to achieve a target CO 2 concentration of 550 μmol/mol, hereafter called elevated CO 2 (eCO 2 ) plots. Soil samples were collected to determine carbon and nitrogen concentrations. After seventy days of sowing, a standardization cutting was performed and then at regular intervals of 21 days the forage was harvested (ten harvest dates) and forwarded to laboratorial analyses. Forage above‐ground biomass production (dry matter (DM): 6,143 vs. 6,554 kg/ha), as well as morphological characteristics (leaves: 71% vs. 68%; stem: 28% vs. 31%), chemical composition (crude protein: 162.9 vs. 161.8; neutral detergent fibre: 663.8 vs. 664.3; acid detergent fibre: 369.5 vs. 381; lignin: 60.1 vs. 64.1 g/kg DM; total C: 45.9 vs. 45.9; total N: 2.8 vs. 2.8; total S: 0.2% vs. 0.2%), organic matter in vitro degradability (573.5 vs. 585.3 g/kg), methane (5.7 vs. 4.3 ml/g DM) and total gas (128.3 vs. 94.5 ml/g DM) production did not differ significantly between CON and eCO 2 treatments ( p > .05). The results indicated that at least under short‐term enrichment, B. brizantha was not affected by eCO 2 .