Comparative evaluation of selected soil moisture monitoring devices

Comparative evaluation on soil moisture monitoring devices was carried out using six equipment; tensiometer, gypsum blocks, water mark sensor, VG meter, Rapitest moisture meter and Rapitest fourway analysis the purpose of the study was Monitor soil moisture content of a bare soil using the instruments listed above, compare the performances of the devices with gravimetric method and to develop and validate mathematical relationships between soil moisture contents by gravimetric method against each of the devices. Soil moisture content was gotten by taking readings with each instrument and a corresponding gravimetric moisture content. Bulk density for the soil was determined to be used for conversion from gravimetric to volumetric moisture content basis. Graphs were plotted for each instrument and corresponding equation was developed which are; tensiometer = 20.444e-0.009x, gypsum blocks y = 0.2891e0.0481x, water marker y = 28.493e-0.025x, VG Meter y = 0.8816x, Rapitest Moisture Meter y = 7.144e0.1608x, Rapitest Fourway Analyzer y = 6.448e0.4531x. From validation procedures result indicate the modeling for tensiometer 0.5, gypsum blocks 0.3, watermark sensor 0.3, vg meter 0.5.