Resumo

CONCEICAO, Luís A. et al. Spatial variability of a maize crop (Zea mays): importance of seeders vertical distribution. Rev. de Ciências Agrárias [online]. 2014, vol.37, n.3, pp.329-339. ISSN 0871-018X.

Among the various factors that contribute towards producing a successful maize crop, seed depth placement is a key determinant, especially in a no-tillage system. The main objective of this work was to evaluate the spatial variability of seeders vertical distribution and crop establishment in a maize crop under different tillage conditions, using precision farming technologies carried out in 2011 and 2012. Considering the lowest coefficient of variation of seed depth placement of 10.1%, best seeder performance was achieved in no-tillage condition increasing forward speed from 4 to 6 km h^-1. A two factor ANOVA showed that the effect of soil mechanical resistance and work speed in no-tillage caused significant differences in seed depth placement. Seeding depth had a significant impact on mean emergence time and percentage of emerged plants and high coefficients of variation suggest a need for improvements in controlling the seeders sowing depth mechanism or more accurate calibration by operators in the field.

Palavras-chave : precision farming; agricultural mechanization; maize; seed depth; no-tillage.

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