Efeitos do mecanismo regulador da profundidade de deposição das sementes de semeadoras-adubadoras sobre a emergência do milho

Abstract

Corn is a crop that stands out in the Brazilian agricultural scene, having great economic and social importance worldwide. Its great use and essentiality have been providing the implementation of cultivation techniques, which has translated into high yields. With the evolution of the technological levels of precision seeders, the concern with the quality of sowing was also increased. According to the regulations, this process directly interferes with seed distribution, sowing depth, plant density and final crop yield. Thus, it is pertinent to evaluate new mechanisms developed for precision seed drills in order to seek improvements in the quality of the sowing process of the maize crop. In this way, starting from the hypothesis that the type of mechanism regulating the depth of seed deposition can directly influence the emergence and development of the crop, this study aimed to evaluate the efficiency of two types of these mechanisms (fixed and rocker), simulating the effect of the type of mechanism of seed deposition depth sowing in soil with superficial stoniness and, also, in soil conditions without impediment to mechanization (not rocky soil). The parameters related to the emergence of corn plants (emergency speed index, longitudinal distribution and plant stand) were evaluated. The results indicate that the rocker limiting system does not differ from the fixed system in the case of soil sowing without impediment to mechanization, and there is no distinction between these in the analyzed variables. However, in the case of sowing in soil with mechanical impediments (rocky), the rocker limiter system presents performance and performance superior to the fixed limiter system, giving a better stand of plants, a lower percentage of failures and doubles and, consequently, a higher percentage of acceptable spacing.