Mixture of tropical forage grasses in pastures: leaf area index, population density and individual tiller characteristics

• Grant number: 21/01848-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2021
• End date: April 30, 2022
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Sila Carneiro da Silva
• Grantee: Gislaine Cristina Barro
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Forage grasses may be combined into functional groups (e.g. contrasting growth and perennation strategies) in such a way that when cultivated in associations they can result in reduced intra-annual variation in herbage production and maximize production potential of the system. In addition, the association can also favor plant biodiversity and augment the environmental services provided by the pastoral ecosystem. In spite of that, knowledge and information regarding tropical forage plants area almost nonexistent since the large majority of published material was produced in temperate and subtropical conditions. The objective of this project is to evaluate the leaf area index, population density and individual tiller characteristics of a C4 grasses association relative to their monoculture. The study will be carried out at ESALQ/USP, Piracicaba, SP, from April 2021 to March 2022. 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), and 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). 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.