Soil penetration resistance under different chiseling intensities and no-tillage with a succession of corn and different winter cover crops

Abstract

In Brazil, most summer crops are grown under no-tillage (NT), however machine traffic and the unplanned use
of crop successions can lead to consolidation or compaction of the soil. The aim of this study was to determine the long-term
effects of chiseling and cropping systems on the penetration resistance of an Oxisol. The experiment began in March 2015,
and included the following tillage systems: (1) no-tillage; (2) no-tillage with chiseling at the start of the experiment using a five-shank
chisel plow (A); (3) no-tillage with chiseling at the start of the experiment using a four-shank chisel plow (B); (4) no-tillage with annual
chiseling (2015, 2016, and 2017) using chisel plow A; (5) no-tillage with annual chiseling using chisel plow B. The crops used in
succession to the corn were black oats, common vetch, forage radish and mixed crops (black oats + common vetch + forage radish). The
soil penetration resistance (PR) decreased in each of the treatments compared to the initial condition of the soil. The chiseling treatments
had similar values for PR (Tukey’s test, p > 0.05), indicating ephemeral changes and reconsolidation of the soil in 6 to 12 months.
The 0.10-0.20 m layer had the highest PR, close to the critical limit; however, the higher PR values under NT did not affect grain yield
in the corn. In conclusion, there is no need for chiseling the soil under NT when a corn/winter cover-crop succession is adopted for three years.