Grazing management strategies for Urochloa decumbens (Stapf) R. Webster in a silvopastoral system under rotational stocking

Abstract

Our objective was to compare herbage accumulation and nutritive value of Urochloa decumbens (Stapf) R. Webster managed under pre‐grazing canopy light interception (LI) targets of 90%, 95% and 100% in silvopastoral system (SPS) and 95% in open pasture (OP; U. decumbens under full sunlight) to establish a pre‐grazing target for SPS of ~43% shade. The evaluations were made during two rainy seasons and one dry season. The total herbage accumulation in SPS was lower than in OP at all LI targets and seasons. However, the difference in total herbage accumulation between SPS and OP was reduced when SPS was harvested at 95% LI, with reductions of 20% and 28% in both rainy seasons (12,191 × 15,324 kg DM/ha and 11,158 × 15,424 kg DM/ha respectively). Moreover, under 95% LI in SPS, crude protein concentration was 18% and 19% greater than that in OP in both rainy seasons (155 × 131 g/kg DM and 144 × 121 g/kg DM respectively), thus representing the optimal pre‐grazing LI target for U. decumbens in SPS. In addition, a canopy height of 20 cm was necessary for 95% LI in OP and a height of 40 cm in SPS. Therefore, U. decumbens should be grazed at 40 cm canopy height, in SPS with ~43% shade to keep 95% LI as the target. However, this target will only be effective if the shade level is maintained, which will reduce height variation over time.

Prediction of aboveground biomass and dry‐matter content in Brachiaria pastures by combining meteorological data and satellite imagery

“…The genus Brachiaria (syn. Urochloa ) comprises 85% of cultivated pastures in Brazil (Jank et al., 2014) generally because of its high resistance to acid soils, wide adaptation and good productive potential in the rainy season (Correa et al., 2020; Machado et al., 2020).…”

Shade and nitrogen fertilization affect forage accumulation and nutritive value of C4 grasses differing in growth habit

“…Although Wilson and Wong (1982) did not find differences for nutritive value attributes of green panic among harvest frequencies, Machado et al. (2020) found decreasing forage dry matter digestibility as grazing was delayed under shade. Also, greater N concentration dilutes the amount of cell wall in the forage.…”

“…There are reports of reduced plant growth and lesser forage accumulation (FA) compared with full sun plants (Cruz, 1996; Fujita et al., 1993; Gómez et al., 2013; Guenni et al., 2008) as well as increased growth (Pang et al., 2019; Wilson, 1996; Wilson et al., 1990). However, interactions between light environment and defoliation management were also described (Machado et al., 2020; Wong & Wilson, 1980).…”

“…Crop Science (Pang et al, 2019;Wilson, 1996;Wilson et al, 1990). However, interactions between light environment and defoliation management were also described (Machado et al, 2020;Wong & Wilson, 1980).…”

Frequência de desfolhação e nitrogênio como determinantes do perfilhamento e do acúmulo de forragem do capim BRS Zuri sob lotação rotativa

“…Os resultados da MFpré e pós-pastejo demonstraram que, de maneira geral, dosséis mantidos mais altos apresentam maior massa de forragem correspondentes, seguindo padrão semelhante encontrado na literatura em diferentes trabalhos com pastagens (Carnevalli et al, 2006;Difante et al, 2010;Barbosa, 2020). A competição por luz é o principal fator determinante da DPP no dossel forrageiro (Machado et al, 2020). Dosséis mantidos mais altos, apresentam perfilhos maiores, em menor densidade populacional (Gastal et al, 2015) e, juntamente com seu potencial genético, a forrageira pode apresentar folhas cada vez maiores, o que pode explicar os maiores IAF e %C para os dosséis mandito sob A5 (Tabelas 5 e 7).…”