Providing food for an ever growing world population under pressure to conserve water
and energy requires the adoption of new methods in agriculture. Precision farming, also known as precision agriculture, aims to improve site-specific farming through data collection, analysis, and management recommendations.
For most crops, irrigated farms can produce 100 to 400 percent higher yields than non-irrigated
farm land. The most efficient methods for delivering water are center pivot and linear irrigation. Variable rate irrigation can provide water at rates depending on the need and thus uses water more efficiently while reducing over- and under-watering. However, precision agriculture relies on technology for data collection and is only as good as the data used as input.
Water is the most important input in agriculture. Skaha has developed a passive microwave radiometer that senses the level of microwave emission emitted by the soil. Microwave emissivity is correlated with soil moisture: dry soil has a higher emissivity than moist soil. Compared to an active radar (e.g. Radarsat), a passive system has higher sensing depth and is less affected by vegetation coverage.
The microwave data are ground-truthed to soil moisture values acquired with high-end soil moisture probes, which measures soil moisture through time-domain reflectometry. These sensors measure propagation time, signal attenuation, and temperature. Dielectric permittivity, volumetric water content, and bulk electrical conductivity are then derived from these raw values. This allows accurate moisture content measurements in soils without performing a soil-specific calibration.