Three-dimensional scanning of soil surface and furrow profiles using a portable and affordable unit

Soil surface and furrow profiles in soil dynamics research and applications are usually measured using manual profile meters and laser-based scanners. Manual profile meters are laborious to use, and laser-based scanners could be expensive and not portable. An approach was developed for measuring soil surface and furrow profiles using a portable and affordable 3D scanner. The developed approach was validated by using the 3D scanner to measure the width and depth of a V-groove (with known dimensions) created in three types of soils (coarse sand, Black Vertosol and Red Ferrosol) at different soil water contents moulded in a soil box. Average error of +/- 1.83% was found for all the three soil types and soil water contents. Results from the 3D scanner were also validated in the field by comparison to profiles measured with a pinned profile meter. In terms of percentage difference in readings, the 3D scanner results showed 16, 5 and 4% greater furrow width, ridge height and cross-sectional area, respectively, and 1% less furrow backfill. These differences were partly due to profile meter pins digging into loose soil and limitation with accurate width measurement. Data acquisition and processing with the 3D scanner unit were significantly faster than with the pinned profile meter. In general, it could be concluded that the developed methodology has the level of accuracy required for soil surface and furrow profile measurements. Furthermore, this approach is a cost-effective alternative to using laser-based scanners. (C) 2020 IAgrE. Published by Elsevier Ltd. All rights reserved.