ИСТИНА

On-the-go sensors measuring soil electrical resistivity (ER) or conductivity (EC) are vital for fast non-destructive soil mapping. Most of the available EC devices, which utilize a four-electrode principle, are bulky, expensive, and can be used only on fallow fields. This limits their applications on small and mid-sized farms with perennials, vegetables, or turf-grass. LandMapperTM ERM, was developed by Landviser Inc. for a broader range of agricultural (horticultural) applications on small to medium fields all year around. The device is portable, fast, accurate, compact, safe, and affordable. It uses fully customized, interchangeable, and easily constructed four-electrode probes, which make it highly versatile for many applications, ranging from ER measurements in the laboratory and soil pits to non-destructive field mapping of topsoil down to 5 m. Field soil ER does not correlate (r=0.1) with water content at average to high moisture conditions, however in humid areas ER correlated with pH (r=0.35), soil texture and resistance to penetration (r=0.5) and generally followed the pre-existing maps of soil series. Yet significantly more variability was revealed with ER within the defined soil map units. Our previous research has shown that ER measurements can also be used to map soil salinity, stone content, impermeable layers, and to monitor water and fertilizer states in soil."