Plantabilidade de soja em sucessão a cobertura de inverno com azevém

Abstract

Soybean crops depend on several factors to achieve their maximum production potential, and one of these factors is the plantability of the crop, which defines the uniformity of plant distribution. The objective of this study was to evaluate the plantability of soybean crops under ryegrass straw, managed at different times. The experiment was carried out in the experimental area of the Federal Technological University of Paraná – Pato Branco Campus, in a randomized block design, bifactorial (3x2), with four replications. The treatments consisted of the combination of three ryegrass sowing methods in a no-till system in the winter period (fertilization in the sowing line, without fertilization and broadcast fertilization) and two times of desiccation of the winter cover (0 and 30 days before soybean sowing). Before soybean sowing, the amount of dry matter in the straw was evaluated according to the sowing methods and times of ryegrass management. After soybean sowing, evaluations were made of sowing depth, emergence speed index, uniformity of plant distribution (normal, double and defective spacing) and initial plant stand. The data were subjected to statistical analysis using the F test of analysis of variance (ANOVA). The analyses were performed with the aid of the R-Studio computer program. It was concluded that the management of ryegrass straw, regardless of the sowing method or desiccation time, did not significantly influence the soybean plantability parameters. However, desiccation performed on the day of sowing compromised the efficiency of the process, hindering soil-seed contact. Therefore, early management of the cover crop is recommended to favor crop establishment.