Atributos físicos, químicos e agronômicos do milho em sistemas de manejo do solo

Abstract

Techniques to promote a balance between the physical, chemical and soil microbiology, is gaining its space, so that is visible productivity growth in more structured soils. It was aimed to evaluate the systems of soil management via their physical and chemical attributes and agronomic characteristics of the maize crop. The treatments were six soil management systems divided in four stages, as follows: without preparation (T0), chiseling operation (T1), two scarification and a leveling disk harrow to break clods and level the ground (T2), plowing and harrowing four destorroadora-leveling (T3), one destorroadora-leveling harrowing (T4) and a scarification operation and a destorroadora-leveling harrowing (T5). For data analysis techniques were used descriptive statistics, multivariate and geostatistical. In the depth of 0,00-0,10 m, with the exception of T3 system that had the lowest values of P and Mg, the preparation of operations did not affect the levels of P, K, Ca, Mg, SB and V%, the other systems, which are considered high. In the depth of 0,10-0,20 m, all systems had low values of K. Ca and Mg values were high, higher for T0, T2 and T4 and T5 for less. Al values were considered average and the MO was considered low at both depths. In the multivariate analysis, it was found that the soil management influenced the similarity between T0 and T3 systems at a depth of 0,00-0,10 me that the T4 and T2 group had a better chemical quality, being influenced by higher Ca , Mg, SB, CEC and V%. In the depth of 0,10-0,20 m, subgroups T2, T3, T4 and T0 had better environmental quality, being influenced by the attributes K, SB, Mg, CTC, V%, MO and pH. In soil physics, density, microporosity and porosity was adequate for all systems and depth, only the macroporosity critical limits aeration. The mechanical resistance to penetration (RP) systems receiving the operations of plowing and scarification did not show high values of PR on the surface and was observed a decompressing effect of the drill shank in the row. In geostatistical analysis showed low variation of RP data from the average, with spherical semivariogram and degree of strong spatial dependence profile and maps of PR in the soil profile, the T0 and T4 systems showed high values of PR on the surface soil. In management systems, the agronomic characteristics of corn did not differ significantly.