Abstract:
Electromagnetic induction (EMI) methods are gaining popularity due to their non-destructive nature, rapid response and ease of integration into mobile platforms for assessment of the soil moisture content, water table depth, and salinity etc. The objective of this study was to estimate and map soil moisture content and organic matter content using DualEM. Two wild blueberry fields were selected in central Nova Scotia and a grid pattern of sampling points was established at each experimental site based on the geostatistical analysis of the ground conductivity survey data. The volumetric moisture content and organic matter was determined for each grid point (n=86 for field 1 and n=56 for field 2) from the both fields. The ground conductivity was measured and recorded with Dual EM at same sleeted grid points. Two comprehensive surveys were conducted in those fields to measure ground conductivity for soil moisture and organic matter estimation in real-time using DualEM and a differential global positioning system.
Linear regression analysis showed that ground conductivity (HCP) was significantly related with the measured moisture content and organic matter (R2 ranged from 0.88 to 0.90) in both fields. The accuracy of the estimated values from the DualEM data was calculated as root mean square error. The estimated soil moisture and organic matter maps showed substantial variation in selected fields. The slope of the both fields was also mapped using automated slope mapping system. The soil and slope maps were overlaid representing high moisture and organic matter content in low lying areas and steep slope areas having less moisture content and organic matter. This information could be used for exploring fertility status of the soil and scheduling site-specific irrigation within fields.
