Association of perennial tropical forage grasses: potential of herbage production and stability and dynamics of tiller population

• Grant number: 19/27582-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2021
• End date: July 31, 2023
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Sila Carneiro da Silva
• Grantee: Larissa Fernanda Garcia
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Forage grass species may be organized into groups of similar functionality (e.g. plants that compete or preserve resources) which provide opportunity for species association in mix pastures that could show greater herbage production with lesser intra-annual variation, contributing for biodiversity and resilience of the pastoral system. For tropical perennial grasses, information regarding species association is scarce, since the majority of experimental work is with temperate and sub-tropical forage plants. The objective of this experiment is to evaluate the potential and the stability of herbage production and the dynamics of tiller population of C4 grasses growing in association relative to their monocultures. The study will be carried out at ESALQ/USP, Piracicaba, SP, from September 2020 to April 2022, concomitantly to other two experiments to evaluate the impacts of tropical forage grasses association on the agronomic responses of the mixtures. Experimental treatments will correspond to three tropical forage grasses (Andropogon gayanus cv. Planaltina, Brachiaria brizantha cv. BRS Piatã and Panicum maximum cv. Massai) cultivated in monoculture and in association (the three species in equal proportions based on the number of viable seeds). Treatments will be allocated to experimental units (180 m2 paddocks) according to a randomized complete block design, with four replications. All pastures (monocultures and association) will be managed under rotational grazing using the pre-grazing target height target of 35 cm and the post-grazing target height target equivalent to 50% of the pre-grazing height (17.5 cm) during two consecutive pasture growing seasons. The response-variables will be canopy light interception and herbage mass at pre- and post-grazing, proportion of ground cover, herbage accumulation, tiller population density and dynamics, tiller structural characteristics, stability of herbage production throughout the year and possible overyieldings and/or underyieldings of each species and of the association. The data will be analyzed using the PROC MIXED of the SAS® 9.4 statistical package and, when appropriate, means comparison will be made using Student's "T" test with P<0.05. Season of the year will be treated as repeated measures. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GARCIA, Larissa Fernanda. Association of perennial tropical forage grasses: herbage production and stability and dynamics of tiller population. 2023. Doctoral Thesis - Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) Piracicaba.