Radicular development and corn leaf (zea mays) under different types of subsolation

The physiological factors that determine the productivity of a crop are influenced by soil compaction. The objective of this work was to evaluate the effect of two types of subsoil in the development of corn and the resistance of a Red Nitosol to penetration. The experiment was carried out in 3 plots of 0,5 ha each, with treatments: minimum cultivation with subsoiler equipped with cutting disc and ripper roller (CMd), minimum cultivation with conventional subsoiler (CMc) and no-tillage system (SPD) as witness. The mean mechanical strength of the soil at the penetration (RP) of 0-0,30 m, plant height, dry mass and maize productivity were measured through a sample mesh of 6 points per plot. Mean RP ranged from 0,51-2,01 MPa in CMc, versus 1,26-1,76 MPa in CMd, while SPD ranged from 1,01-1,76 MPa. The height of plants was better in the minimum cultivation, and in CMd ranged from 1,87-2,09 m, compared to 1,65-2,09 m in CMc, and 1,76-1,98 m, demonstrated better conditions for CMd. The root dry mass was lower in SPD, 30-60 g plant(-1), CMd increased in the lower limit, showing a variation of 40-60 g plant(-1), and an increase in CMc, of 30-70 g plants(-1). Maize productivity was higher in CMd, followed by CMc and SPD, ranging from 10,2 to 17,7 Mg ha(-1), at 8,70-17,70 Mg ha(-1), and 8,7 to 11,7 Mg ha(-1) respectively, demonstrating that the disc subsoiler generates better conditions for corn development.