Atributos de máquina, solo e planta após o manejo com plantas de cobertura e profundidades de atuação da haste sulcadora, em latossolo compactado

Abstract

The system of direct sowing is characterized by the minimum tillage of the soil and maintenance of vegetal residues in cover. However, neglect with soil management has systematically provided the emergence of compacted layers in agricultural areas conducted in this system, which may lead to a decrease in crop productivity. Thus, the objective of this work was to evaluate the machine, soil and plant parameters as a function of the cultivation of cover plants and four depths of the fertilizer routing rod, in a compacted Oxisol conducted in a no - tillage system. The experiment was carried out in two agricultural crops (2013/2014 and 2014/2015) in the experimental area of UTFPR, in a dystroferric Red Latosol, with a very clayey texture (76% clay). The experiment was conducted in a randomized complete block design, and the treatments were arranged in two - factor and four replicate bands, totaling 32 experimental units. The main treatments were composed by the combination of four depths of fertilizer routing (6.5, 9.5, 12.5 and 15 cm) in the corn sowing process and the secondary ones by the cultivation of two cover crops Winter (black oat and forage turnip). The obtained data were submitted to the analysis of variance to verify the effects of the factors depths of rod actuation, soil cover plants and their interaction. When the F test was significant at 5% probability, the means were compared by the Tukey test for the qualitative factors (winter cover plants). For the quantitative factors (furrow depths) and interactions, the polynomial regression test was applied. The deepening of the furrowing rod increased the traction force and the power required in the bar in the sowing process, as well as reducing the average velocity of the mechanized set and the specific traction force, and despite generating a greater mobilization of the soil in the sowing line. Has been shown to be an efficient management practice to increase maize productivity. The use of cover plants and stem depths, among themselves, did not modify soil resistance parameters to soil penetration, density and porosity, in the intercrop line. The final population of plants, seedling emergence speed index and maize production components did not vary according to the depth of action of the furrowing rod.