Modeling biological nitrogen fixation in ipyporã brachiariagrass with APSIM and CROPGRO models

• Grant number: 19/18574-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2021
• End date: January 02, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Carlos Guilherme Silveira Pedreira
• Grantee: Fagner Junior Gomes
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant(s): 24/14515-7 - 2024 ASA, CSSA, SSSA International Annual Meeting, AR.EXT
• Associated scholarship(s): 21/11742-4 - CROPGRO-Perennial Forage model: parameterization of biological nitrogen fixation in Ipyporã brachiariagrass, BE.EP.PD

Abstract

Nitrogen (N) is an essential nutrient for forage grasses and it is often associated with the intensification of forage-based animal production systems. Biological nitrogen fixation and the use of of N-fixing bacteria is a low-cost and sustainable option for supplying plants with N, against a scenario of increased production costs and increased environmental pressures. However, there are no studies with crop models to simulate these systems with the contribution of bacterial inoculation as a source of N supply to the forage. The objective of the present study is to parameterize and test the efficiency of the APSIM-Tropical Pasture and CROPGRO-Perennial Forage models to simulate the productivity of the Ipyporã brachiariagrass [Brachiaria spp. (syn. Urochloa spp.) cv. BRS331 Ipyporã] under the effect of bacterial inoculation. For this, data from an experiment performed at Embrapa Agrossilvipastoril in Sinop - MT, in a randomized complete block design, with four treatments applied in pastures of Ipyporã brachiariagrass, with three replicates: (1) without nitrogen fertilization (control); 2. fertilized with 80 kg N ha-1 y-1; (3) inoculation with Azospirillum brasilense; (4) fertilized with 80 kg N ha-1 y-1 + inoculant. Afterwards, calibrations of the models will be carried out and a comparative analysis between the models to simulate the pasture productivity for all the scenarios. The expected results are to construct parameterizations of the models with good efficiency in estimating the productivity of a hybrid of Brachiaria in monoculture and fertilized, managed under rotational defoliation and to estimate the effect of the bacterial inoculation in these systems.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BOURSCHEIDT, MAIRA L. B.; GOMES, FAGNER J.; PEDREIRA, CARLOS G. S.; BOOTE, KENNETH J.; HOOGENBOOM, GERRIT; PEREIRA, DALTON H.; PEDREIRA, BRUNO C.. Highlighting the benefits of biological nitrogen fixation on agronomic, physiological, and nutritive value traits of brachiariagrass. EUROPEAN JOURNAL OF AGRONOMY, v. 143, p. 7-pg., 2022-12-31. (19/18574-0, 21/11742-4)