Thermography as a remote sensing tool of soil surface microtopography in the presence of mulch

Abstract

In this study we present an infrared thermography technique that can be useful to detect soil surface microtopography in the presence of mulch. Laboratory test were carried out where the performance of the technique was evaluated in a surface with artificial rills and in a surface with microtopography created by water erosion, for different mulch cover conditions (bare soil, 2 and 4 t ha-1). Microtopography was detected applying heated water on the soil surface and recording the temperature with an infrared video camera. The technique allowed us to obtain 3D models of soil surface elevation both in the scenario with artificial rills and in the scenario with microtopography created by water erosion. With this technique it was possible to identify preferential flow paths and the different elements of microtopography, even in the presence of 2 t ha-1 of mulch covering the soil surface. In the scenario with cover density of 4 t ha-1, the detection of the thermal radiation emitted by the soil surface was severely affected, resulting in a decrease of the performance of the technique.