ASSESSING THE POTENTIAL OF PLANT GROWTH-PROMOTING BACTERIA TO REPLACE NITROGEN FERTILIZATION AND ENHANCE ANNUAL RYEGRASS (Lolium multiflorum) FORAGE PRODUCTION AND NUTRITIVE VALUE

• Grant number: 23/08363-7
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: August 01, 2024
• End date: November 30, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Ricardo Andrade Reis
• Grantee: Carlos Eduardo Lima
• Supervisor: Bruno Carneiro e Pedreira
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Institution abroad: University of Tennessee (UT), United States
• Associated to the scholarship: 21/05858-0 - Effect of nitrogen fertilizer sources on forage production and performance of cattle reared in marandu grass pasture, BP.IC

Abstract

Pasture is a major feeding source for livestock production in Tennessee, thus, it is necessary to explore alternative forages to diversify livestock production. Annual Ryegrass is an alternative to produce forage, potentially increasing overall profitability compared to other forage systems. The N is the most limiting nutrient for plant growth worldwide, and mineral fertilization is a common practice to enhance stocking rate, animal performance, and system productivity for forage-livestock systems. The use of plant growth-promoting bacteria (PGPR) has been considered an excellent strategy for the sector, as it can lead to qualitative and quantitative improvements in forage production and, consequently, increase productivity and reduce the use of chemical inputs, generating less environmental impact. The specific goals of this project are to quantify the effects of bacterial inoculation on the establishment and forage accumulation and nutritive value of Annual Ryegrass, in addition to quantifying the effects in the greenhouse. The field trial will be carried out in two sites: Crossville and Greeneville, TN, USA, while the greenhouse trial will be carried out at the University of Tennessee, TN, USA. The experimental period will be from August to December 2024. The experimental design will be a randomized complete block, with four replicates. The treatments in the field and greenhouse will be Azospirillum brasilense Ab-V5 and Ab-V6 associated or not with 50 or 67 kg of nitrogen per hectare: T1 - Non-inoculation and no N; T2 - inoculated without N; T3 - non-inoculated + 50 Kg/ha of N; T4 - non-inoculated + 67 Kg/ha of N; T5 - inoculated + 50 Kg/ha of N; T6 - inoculated + 67 Kg/ha of N. In the field, three to four weeks after planting, the number of plants in two 1-meter sessions will be counted to evaluate the impact on plant population. Canopy height will be monthly measured. The forage nutritive value will be measured. In the greenhouse, thirty-five days after emergence the plants will be removed from the trays, and shoots and roots will be separated for further analysis, to ascertain the root volume and the shoot to evaluate dry mass and nutritive value. This research is of great importance as it will make it possible to reduce the use of nitrogen fertilizers without affecting productivity or even increasing it. This could help, especially small farmers, to reduce costs and develop cleaner agriculture.