Measuring and interpreting soil electrical conductivity for precision agriculture

摘要

Soil electrical conductivity has been used as a surrogate measure for such soil properties as salinity, moisture content, topsoil depth, and clay content. The objective of this research was to investigate accuracy issues important to the collection of profile-weighted soil electrical conductivity (EC_a) data with a mobile electromagnetic induction sensor. Sensor drift was potentially a significant fraction of within-field EC_a variation. Use of a calibration transect to document and adjust for this drift was recommended. Effects of positional offset and variations in sensor operating speed and height were documented. Multiple measurements of EC_a on a field were similar if they were obtained at the same time of year. However, there was a significant effect of soil moisture and temperature differences across measurement dates spanning a 12-month period.