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.