Escarificação mecânica e biológica do solo e a produtividade do milho

Abstract

The high clay content of the soils of the Southwest of Paraná allied mechanical practices performed outside the optimum moisture range, has triggered losses in crop productivity mainly to the root development restriction. Thus, farmers have opted for investment in tillers but not always reach out expected effect. Thus, the present study had as objective to verify the effect of the mechanical preparation and the cover plants on the physical attributes of the soil and corn yield. The treatments used were 4 variations of cover plants: forage turnip (N), common vetch (E), oats (A) and the consortium (C) Between two and three forms of soil management: no-tillage (PD), Scarified no-till (PDE) with Terrus model GTS [marca registrado] brand equipment and no-tillage minimum tillage (PDPM) with subsoiler Jumbo brand Jam [marca registrado] . The evaluations were carried out before mechanical soil management, after the management and after the harvest of the summer crop. After the mechanical management, the proportion of covered soil was evaluated. The physical attributes of the soil were analyzed, being: soil density, macroporosity, microporosity, total porosity and resistance to penetration. No-tillage had a higher coverage rate compared to other treatments, while no-tillage had the lowest coverage, 76% and 37%, respectively. After mechanical scarification, there was a significant reduction of soil density and increase in macroporosity when compared to no-tillage. After harvesting the maize with the turnip and the consortium there was lower soil density and higher macroporosity where allied to the mechanical management. As for the resistance of the soil to the penetration (RP) initially the layer of 0.07 to 0.22 m presented values above 2 MPa. Both scarification and subsoiling reduced PR in compacted layers. After harvesting corn, 9 months after soil management, the effect persisted, but with less intensity. Despite improvements in physical soil characteristics, mechanical operations had no effect on maize grain yield in a high precipitation year.