Data/hora: 03/06/2024 11:16:57

Biblioteca(s): 	Epagri-Sede.	
Data corrente: 	09/12/2021	
Data da última atualização: 	09/12/2021	
Autoria: 	BARBOSA, A. M.; BALDISSERA, T. C.; GARAGORRY, F. C.; LOPES, C. F.; RECH, Â. F.; RIBEIRO FILHO, H. M. N.	
Título: 	Does the shade and canopy height affect herbage mass and structure of annual ryegrass?	
Ano de publicação: 	2021	
Fonte/Imprenta: 	In: REUNIÃO DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 56., 2021, Florianópolis. Resumos... Brasília: Sociedade Brasileira de Zootecnia, 2021. p. 43	
Idioma: 	Inglês	
Conteúdo: 	The shading effect caused by trees in an integrated crop-livestock system (ICLS) may reduce plant growth and
development, modify herbage structure and grazing behaviour. This study aimed to assess the influence of
shading and canopy height management on herbage mass and structural components of Lollium multiflorum
Lam ?Barjumbo?. The experiment was conducted at Epagri Lages, SC, in sixteen paddocks with 125m² each,
comparing two pasture systems: an ICLS shaded with Acca sellowiana or a full sun area, and four canopy
heights: 12, 17, 22 and 27 cm. Herbage mass (HM, kg DM ha-¹) was determined in three 0.25 m2 frames per
paddock, by cutting at the upper strata (50% of canopy height) and drying in forced circulation oven at 55°C.
Herbage bulk density (g DM (cm³)-¹) was determined by multiplying HM of the upper strata by the strata height.
Sheath length (SL, cm) was measured with a ruler, from ground level until ligula of the last mature leaf. Tiller
density (un (m²)-¹) was counted using four 0.0625 m² frames. All data were analysed by two-way ANOVA and
Tukey test at 5% of significance level in R environment. The HM at the upper strata was higher in full sun than
shade, averaging 487 and 313 kg DM ha-¹, respectively and higher in 27 cm compared with 22 cm, whereas 17
and 12 cm were similar, averaging 641, 457, 276 and 244 kg DM ha-1, respectively. It was observed interaction
for bulk density between canopy height and shade. In full sun, bulk density was higher in 17, 22 and 27 cm
compared with shaded environment, but similar in 12 cm for both pasture systems. The sheath length was
highest in 27 cm, followed by 22, 17 and 12 cm (17, 15, 11, 9 cm, respectively), but did not differ between full
sun and shaded environment. Tiller density was higher in full sun than shade, averaging 1980 and 1684 un (m²)-
¹, respectively. The altered light environment on shade had a negative impact mainly on tiller density, which
could lead to the reductions in HM and bulk density. Moreover, it could decrease bite mass and herbage intake
in grazing conditions. In contrast, annual ryegrass sheath length was affected in a small extension by shade.
Additional studies addressing grazing behaviour are necessary to set canopy height targets in such conditions.	
Palavras-Chave: 	bulk density; canopy height; integrated crop-livestock system.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_50466.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
Exemplares: 	Epagri-Sede - (106540-1) - UPC - PL - DD -  -  -  - DIS