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Equi-pf Automated Soil Moisture Release Curve Apparatus News
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Oregon State University Validates Equi-pF PerformanceUnder
the supervision of Professor Jeff McDonnell a team of his students at
Oregon Sate University (Corvallis, Oregon) have validated the
performance of Equi-pF using two methods:
- Testing a number of grades of Accusand and comparing the Equi-pF results with published data on these Accusands.
- Testing
a number of soil cores taken from the HJ Andrews Experimental Forest
and comparing the Equi-pF results with historical data from cores from
the same site.
The result of the validation tests proved the
suitability of Equi-pF for the generation of Soil Moisture Release
Curves and also highlighted some significant extra features provided by
the system which make it an even more useful tool for Equi-pF users.
More Info >>
Lincoln University using Equi-pFUnder
the supervision of Assoc. Prof. Graeme Buchan, PhD student Sam Carrick is
using Equi-pF as part of his study of the modelling of infiltration and
preferential flowpaths through layered soil columns
The project
is centred on measurement of the hydraulic characteristics of four
large lysimeters containing intact soil columns representative of
extensive areas of the Canterbury Plains. The project focuses on the
behaviour of the pore network at soil moisture conditions mainly above
‘field capacity’ (0 to -10kPa), where preferential flow paths are
likely to be activated.
An experimental setup has been
constructed to enable simultaneous measurements on two lysimeters, with
the following parameters automatically measured by a datalogger at 1
minute intervals for each lysimeter:
• Infiltration & drainage rates.
• Soil water potential, using 30 tensiometers distributed over 4 depths.
• Volumetric soil water content, using 4 TDR probes located at 4 depths.
• Soil & air temperatures.
The
Equi-pF machine is being used at this stage of the project, to test the
accuracy of measurements of the water retention relationship obtained
from standard suction tables. This aspect is critical, as the
infiltration and early-stage redistribution of water in field soils are
dominated by the larger drainage pores, whose characteristics can be
revealed by the Equi-pF.
Papers on the Lincoln University work will be available soon. |
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