Intercropping systems and nitrogen rates in irrigated corn second crop

• Grant number: 21/09757-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2022
• End date: February 28, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Vagner do Nascimento
• Grantee: Mikaelle Eduarda Rocha Frota
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

The adoption of intercropping corn with cover crops (poaceas and fabaceas) is an expanding and frequent agricultural practice in the context of tropical agriculture because it is sustainable, innovative and profitable, being an excellent alternative in the search for increments of crop residues (straw) and release of nutrients in the soil-plant system, mainly nitrogen (N) due to their losses, as well as the possibility of reducing the N dose in topdressing in the corn crop. Thus, the objective of this research will be to evaluate the agronomic and productive performance of corn second crop irrigated by sprinkler, in single crop and intercropped with cover crops and application of nitrogen doses in cover. The project will be developed from November/2021 to October/2022, in a soil classified as a dystrophic Red Argisol with a typical sandy texture. The experimental design will be randomized blocks in a 4x4 factorial scheme, consisting of single corn and intercropped with cover crops (Crotalaria spectabilis, Urochloa ruziziensis and C. spectabilis + U. ruziziensis) and four nitrogen rates (zero, 40, 80 and 120 kg ha-1) in split form coverage with half (50%) of the dose in the phenological stage V5 and half (50%) in V8, with 4 repetitions. Will be evaluated in corn crop: plant dry matter, leaf nitrogen content, relative leaf chlorophyll content (SPAD Index), final plant population, average plant height, ear insertion height, stem diameter, number of rows of grains per ear, number of grains per row, mass of one hundred and grain yield. The photosynthetically active radiation (RFA) will be evaluated in the single crop and in the intercropping of corn with cover crops. In the statistical analysis of the variables evaluated, the data will be submitted to the evaluation of statistical assumptions and analysis of variance. To verify the isolated effects and the interaction between the factors, the means will be compared by the Tukey test, adopting a 5% significance level (p<0.05). The effect of nitrogen doses will be analyzed by polynomial regression, adjusting models of linear and quadratic equations significant by the F test.(AU)