Validation of automated measurements of soil tillage variables with laser and ultrasound sensors¹

Validação das medições automatizadas das variáveis de mobilização do solo com sensores laser e ultrassom

HIGHLIGHTS:

Ultrasound underestimates the variables modified roughness, elevated area, mobilized area, blistering, and thickness.

Readings of cut-out and mobilized profiles by ultrasound were divergent.

Readings of natural profile by both sensors was similar to that obtained with the conventional profilometer.

ABSTRACT

The quality of soil tillage can be measured with a specific device called profilometer, which provides information on roughness, mobilized area, blistering, and thickness in disturbed soils. However, it is an outdated device, requiring many hours of field and office work. Thus, the objective of the present work was to develop an electronic profilometer using laser triangulation and ultrasound sensors for measurement of digitally mobilized soil profile. The results obtained were compared to those acquired with a conventional sliding bar profilometer to evaluate the accuracy and efficiency of the sensors. The experiment was conducted in a completely randomized design under a controlled environment. The variables were measured seven times using the three profilometers (laser, ultrasound, and conventional) in the original, elevated, and mobilized soil profiles. The electronic profilometer with ultrasound differed in all the measurements when compared to the conventional profilometer, which differed from the laser sensor only in modified roughness.

Key words:
conventional tillage; air and water infiltration; soil compaction