Yield Component Responses of the Brachiaria brizantha Forage Grass to Soil Water Availability in the Brazilian Cerrado

Abstract

Brazil is one of the world's largest producers of beef cattle and dairy products, which requires high forage yield to attend grass-fed animals' demand. Among the grass species adopted in the forage production system in Brazil, the Brachiaria genus stands out. This genus comprises nearly 85% of all planted forage area. In general, forage production systems in Brazil are essentially rainfed, and thus susceptible to seasonal soil water stresses. Selecting the suitable Brachiaria cultivar for lands susceptible to periodic waterlogging and dry spells is crucial to enhance forage yield, and consequently, to reduce the environmental footprint of the livestock sector. In this research, we investigated the performance of three recent commercial Brachiaria brizantha cultivars (Piatã, BRS Paiaguás, and MG13 Braúna) extensively adopted in Brazil's grazing systems subjected to different ranges of soil water potential. For three cutting periods, yield related-variables (e.g., plant height, leaf area, dry biomass, and water use efficiency) were measured. Our results point to the existence of a low drought-resistant trait among cultivars, indicating the need for releasing better-adapted cultivars to cope with reduced soil water availability. All cultivars achieved higher performance at soil water pressure head between −15 kPa and −25 kPa; and in general, the cultivar. Piatã showed slightly superior results to most of the treatments.

IMPACTS OF WATER STRESS ON Urochloa brizantha FORAGE CULTIVARS

“…Only the MG4 cultivar did not have its productivity affected by the water deficit, and in these conditions, it was the most productive or was present in this group. Reductions in total and leaf biomass were also observed in studies conducted with U. brizantha cultivars subjected to water deficiency (Santos et al, 2013;Kroth et al, 2015;Pezzopane et al, 2015;Silva et al, 2020;Souza et al, 2021).…”

“…Some Urochloa cultivars used in extensive systems, such as Marandu and MG5 Vitória, are widely known for their high productivity and drought tolerance (Omote et al, 2021). The impacts of water deficit on the performance of forage plants of the Urochloa genus have been studied to recommend more drought-tolerant species for pasture establishment in semi-arid regions (Santos et al, 2013;Kroth et al, 2015;Pezzopane et al, 2015;Lopes et al, 2016;Beloni et al, 2018;Cheruiyot et al, 2018;Duarte et al, 2019;Silva et al, 2020;Souza et al, 2021). In most of these studies, a reduction in aboveground biomass and leaf area, as well as an increase in leaf senescence, was observed.…”

Dynamics of Carbon and Soil Enzyme Activities under Arabica Coffee Intercropped with Brachiaria decumbens in the Brazilian Cerrado

“…This can be explained by the high capacity of pastures for shoot production, the particularly well-developed root system [ 28 ] and the positive management effect when plant residues are left on the soil surface. Some brachiaria species grow well in the soils of the Brazilian Cerrado, producing large amounts of shoot and especially root biomass, and are efficient in storing C in the soil profile [ 28 , 29 ].…”

Effects of Fertilization Types and Base Saturation on the Growth and Water Productivity in Panicum maximum cv. BRS Zuri

“…This means that the greater the amount of root, the greater the possibility of regrowth and tillering of the Zuri grass. The production capacity of the aerial part of a plant depends on the interaction with the root system since the roots are responsible for absorbing nutrients and water [39].…”