Drs. Larry Parsons and Wije Bandaranayake of the University of Florida / IFAS Citrus Research & Education Center in Lake Alfred, FL carried out research on one of these new soil moisture sensors, the ECH2O EC-5 manufactured by Decagon Devices. Their study evaluated the sensors in terms of volumetric soil water content estimation, probe-to-probe signal variability, response to fertilizer-induced salinity, soil volume sampled by the probes, sensitivity to pockets of air or dry soil, response to compaction (bulk density changes), and response to changes in soil temperature.
The results were published in the July-August 2009 issue of the Soil Science Society of America Journal and were presented at the annual meetings of the Soil Science Society of America held in November 2007 in New Orleans, LA. The work was funded in part by the Southwest Florida Water Management District.
Results showed that the new sensor has several advantages. The ECH2O EC-5 was not sensitive to salinity or temperature fluctuations. Although the soil volume sampled by the probe was small (about 15 cm3), the probe responded well to changes in soil water content in the field. The change in probe response was negligible when soil pores (diameter 0.95 cm) were created near the probe surface. Probes were sensitive to changes in bulk density. Signal output increased when soil was compacted. Probe-to-probe output signal variation and response to differences in bulk density can affect the estimation of field water content unless necessary correction factors are utilized.
Soil probes can be useful for monitoring soil water movement, estimating soil water content, and scheduling irrigation. They can be used on a variety of soils and with numerous crops. With a datalogger, soil water content can be monitored continuously over time and changing trends can be noted. Soil water data from these probes can be transmitted by radio to computers at other locations. Research using these and other sensors is continuing at the University of Florida to investigate ways to keep irrigation water in the main root zone, reduce deep percolation water losses, and minimize irrigation water use. With sensors such as these, improved irrigation efficiency is possible.
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The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://soil.scijournals.org/cgi/content/abstract/73/4/1378.
Soil Science Society of America Journal, http://soil.scijournals.org, is a peer-reviewed international journal published six times a year by the Soil Science Society of America. Its contents focus on research relating to physics; chemistry; biology and biochemistry; fertility and plant nutrition; genesis, morphology, and classification; water management and conservation; forest, range, and wildland soils; nutrient management and soil and plant analysis; mineralogy; and wetland soils.
The Soil Science Society of America (SSSA) is a progressive, international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use.
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