Effect of biological N2-fixation, plant litter decomposition, and excreta on nutrient cycling in legume-grass and grass-N system

• Grant number: 18/08567-3
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): October 23, 2018
• Effective date (End): October 18, 2019
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Ana Cláudia Ruggieri
• Grantee: Vanessa Zirondi Longhini
• Supervisor abroad: Jose Carlos Batista Dubeux Junior
• Home Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Local de pesquisa : University of Florida, Quincy (UF), United States
• Associated to the scholarship: 16/11086-1 - Mitigation of greenhouse gases in pastures Marandu Grass managed with legumes or nitrogen fertilizer, BP.DR

Abstract

The purpose of the internship abroad with Prof. Dr. José Carlos Batista Dubeux Junior, at the University of Florida, North Florida Research and Education Center (NFREC) is to improve knowledge in the area of nutrient dynamics and performance of forages in grassland systems. During the internship, we will discuss methodologies and will analyze the results obtained in the trial. The major goal is to understand the limitations in the inclusion of legumes in grazing systems, as well as the divergences of results found in the literature. For this reason, this proposal will allow to evaluate the litter deposition and decomposition under three forage systems in order to better understand nutrient cycling processes in these different systems. Experimental treatments include 1) N-fertilized bahiagrass (summer) plus N-fertilized cool-season grass (cereal rye and oat) (winter); 2) rhizoma peanut (RP; Arachis glabrata)-bahiagrass (summer) and clover/cool-season grass (winter); and 3) bahiagrass with no N fertilizer or summer legume plus clover/cool-season grass (winter), in a randomized complete block design, with three replicates. Biological N2-fixation will be measured using the natural abundance technique. Litter deposition and decomposition will be measured to verify the nutrient recycling potential and nutrient turnover rate of each system. The obtained results will be analyzed using standard statistical packages (e.g., SAS) using mixed models to account for both fixed and random effects. (AU)