Crop residues and nutritional composition of corn intercropped with cover crops and nitrogen rates

• Grant number: 21/14549-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2022
• End date: December 31, 2022
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Vagner do Nascimento
• Grantee: Vinicius Carvalho dos Santos
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

The intercropping systems of corn with cover crops combined with nitrogen (N) doses and inoculation via foliar of plant growth-promoting bacteria are innovative, sustainable and low-cost strategies, with effects on greater accumulation of nutrients in plant tissues and input of crop residues (straw), followed by N and carbon release in the soil-plant system. Thus, the objective of this research will be to evaluate the effects of intercropping systems of corn with cover crops and nitrogen doses in cover on the nutritional status, incidence of solar radiation and on the yield of irrigated corn second crop and its inputs of crop residues and nutrients. The research project will be developed in the autumn-winter of 2022 in the municipality of Dracena, SP, belonging to the Nova Alta Paulista region, in a typical sandy-textured Red Ultisol. The experimental design will be randomized blocks in a 4x4 factorial scheme, consisting of single maize and intercropped with cover crops (Crotalaria spectabilis, Urochloa ruziziensis and C. spectabilis + U. ruziziensis) and four doses of N (zero, 40, 80 and 120 kg ha-1) in split form covering with half (50%) of the dose in the phenological stage V5 and half (50%) in V8, with four repetitions. It will be evaluated in corn crop: initial and final plant population, relative chlorophyll content (SPAD Index) in the leaves at stages R1, R3 and R5, leaf concentration of N, P, K, Ca, Mg and S, dry matter accumulation (DM) in the whole plant and its different organs, accumulation of nutrients in the whole plant and grain yield. In all treatments, photosynthetically active radiation (RFA) will be carried out in the upper, middle and lower thirds of the canopy, perpendicular to the plant lines at stages R1, R3 and R5 of the corn crop. After harvesting the corn crop, the DM yield and nutrient accumulation of the aerial part of each treatment will be performed. 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)