ABSTRACT Seed metering system and tractor-seeder forward speed are factors that affect sowing. Therefore, this study aimed to evaluate sowing and agronomic components of corn as a function of seed metering mechanism and tractor-seeder forward speed, in addition to evaluating the yield data obtained from a harvester with a yield monitor. The soil of the area is classified as Distroferric Red Latosol. The experiment was set up in the second crop season of 2018 and treatments consisted of two seed metering mechanisms (M) (pneumatic and mechanical), and tractor-seeder forward speeds (S) (3, 5, 7, and 9 km h−1). The pneumatic system promoted the best longitudinal distribution, with values above 90%, and the increased sowing forward speed reduced normal spacings and increased failure. The interaction M × S indicated that pneumatic seeder promotes the best stand at the highest forward speed, normal spacing, and less failure. The yield data showed less variation with increasing forward speed, and the best result was observed for the mechanical seeder at 5 km h−1 when these data are grouped into yield classes.

ABSTRACT The way the soil is managed can influence its structuring and, consequently, crop yield. Thus, this study aimed to evaluate the effect caused by the management systems plowing followed by two intermediate harrowing operations, intermediate harrowing, chiseling, chiseling followed by intermediate harrowing, cross chiseling followed by intermediate harrowing, and non-tillage on soil and agronomic attributes of the soybean crop. A randomized block design with four replications was used. The percentage of soil cover, soil resistance to penetration, number of plants per meter, longitudinal distribution of seedlings, and soybean yield were evaluated. The data were submitted to analysis of variance by the Tukey test at 5% probability, and use of geostatistics for soil resistance to penetration. The system without soil tillage provides the best straw preservation but affects the longitudinal distribution of soybean seedlings. The use of intermediate harrowing for managing crop residues or soil tillage leads to the greatest compaction problems. Chiseling is efficient in maintaining compaction values below critical values up to a depth of 0.20 m when working at 0.35 m. Soil yield is not affected by soil management systems when the pluviometric regime is adequate to crop requirements.