Laboratory evaluation of dual-frequency multisensor capacitance probes to monitor soil water and salinity |
| |
Authors: | J L Starr D J Timlin P M Downey I R McCann |
| |
Institution: | (1) USDA-ARS Hydrology and Remote Sensing Lab, Bldg. 007, 10300 Baltimore Ave., BARC-W, Beltsville, MD 20705, USA;(2) USDA ARS Crop Systems and Global Change Lab, Bldg. 001, Rm. 342, 10300 Baltimore Ave., BARC-W, Beltsville, MD 20705, USA;(3) USDA-ARS Environmental Management and Byproduct Utilization Lab, Bldg. 007, 10300 Baltimore Ave., BARC-W, Beltsville, MD 20705, USA;(4) Department of Bioresources Engineering, University of Delaware REC, Georgetown, DL 19947, USA |
| |
Abstract: | Real-time information on salinity levels and transport of fertilizers are generally missing from soil profile knowledge bases.
A dual-frequency multisensor capacitance probe (MCP) is now commercially available, for sandy soils, to simultaneously monitor
volumetric soil water content (VWC) measured as a percentage and salinity as a unitless volumetric ion content (VIC). The
objectives of this research were to assess the relationship of salinity and water content with these dual-frequency MCPs under
laboratory conditions, and assess its potential for field use in sandy soils of the mid-Atlantic region of the US. Water and
salinity studies were conducted in two sand-filled PVC columns, 1.2 m long by 0.25 m ID. Each column was instrumented with
ten dual-frequency capacitance sensors and two thermocouple temperature sensors. Four salinity levels were studied in the
two columns using 0.5, 1, 2, and 4 dSm−1 NH4NO3 solutions. Water, salinity, and temperature readings were continuously recorded at 1-min intervals. The VIC values were found
to be primarily qualitative, but combined with real-time VWC measures the probe could still be an important fertigation management
tool to provide near-continuous real-time information on fertilizer penetration, spread and subsequent changes during crop
growth.
|
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|