Abstract

Knowledge of indicators of soil physical quality is of paramount importance for better understanding of soil-plant relationships. These indicators include the bulk density and soil resistance to penetration. The objective of this study was to evaluate the use of four cover crop species in the process of reducing the soil density and its resistance to penetration in areas managed under no-tillage system. The species denominated “revitalizers” of the soil structure were considered as treatments: Dolichos lab lab,Mucuna aterrimum, Sorghum bicolor and Mucuna aterrima, in addition to the witness (without cultivation). Soil samples were taken from the bulk density 0.0 to 0.1, 0.1 to 0.2, and of 0.2 to 0.3 m depth under two collection conditions, row and inter-row. Soil resistance to penetration was determined by penetrometer, with electronic data storage. We considered two experimental designs 5 × 3 × 2 and 5 × 4 × 2 factorial with five treatments (four species of area coverage and fallow); three depths of soil bulk density and four depths for penetration resistance, two conditions of collection. The statistical data provided was based on the analysis of variance and the treatment means were compared by the Tukey test at 5% significance. The evaluated species, specially the S. bicolor, the D. lab laband the M. aterrima, presented a promissory effect for the improvement of the structural state of the soil in comparison to the area without cultivation.

Key words: Compaction, soil resistance, bulk density.