Intercropping systems, nitrogen rates and inoculation with Azospirillum brasilense in second crop maize

• Grant number: 20/00357-0
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2020
• End date: October 31, 2022
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Vagner do Nascimento
• Grantee: Vagner do Nascimento
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Associated researchers: Borja Velazquez Marti ; Carolina dos Santos Batista Bonini ; Marcelo Carvalho Minhoto Teixeira Filho ; MAURICIO ANDRÉS MOLINA ROCO ; Orivaldo Arf ; Ronaldo Cintra Lima ; Samuel Ferrari

Abstract

Alternatives of maize intercropping systems with cover crops coupled with technologies such as nitrogen (N) rates and inoculation of growth promoting bacteria are promising strategies to promote increases in phytomass and grain yield, as well as reduce N rates in coverage in stressful environment. Thus, the objective of this study was to evaluate the agronomic and productive performance of second crop maize, in single crop and intercropped with cover crops coupled with nitrogen rates in cover and foliar application of Azospirillum brasilense inoculant in a stressful environment. The research project will be developed in the autumn-winter of 2020 and 2021 in the country of Dracena, SP, belonging to the Nova Alta Paulista region, in a typical dystrophic Red Ultisols of sandy texture. Two experiments will be conducted. Experiment 1 will be conducted in a randomized complete block design in a 4x2 factorial scheme, consisting of single maize cultivation and intercropping with cover crops (Crotalaria spectabilis, Urochloa ruziziensis and C. spectabilis + U. ruziziensis) in the presence and absence of application. leaf route (at stage V4) of the inoculum containing Azospirillum brasilense, with 4 replications. An inoculant containing A. brasilense strains AbV5 and AbV6 (2 × 108 viable cells mL-1) and the dose of 500 mL ha-1 will be used. In experiment 2, the experimental design will be randomized blocks in factorial scheme 4x4, consisting of single maize and intercropped with cover crops (C. spectabilis, U. ruziziensis and C. spectabilis + U. ruziziensis) and four doses of N ( zero, 40, 80 and 120 kg ha-1) in partial coverage with half (50%) of the dose at the V5 phenological stage and half (50%) in V8, with 4 repetitions. Will be evaluated in the corn crop in the two experiments: leaf nitrogen content, chlorophyll content, final plant population, average plant height, ear insertion height, stem diameter, number of grain rows per ear, number of grains per row, one hundred grain mass and grain yield. The results will be submitted to analysis of variance (F test) and means compared by Tukey test at 5% significance for Azospirillum brasilense intercropping and inoculation systems, as well as adjusted for polynomial regression equations for N doses. Splitting will proceed if significant interaction occurs between sources of variation. (AU)