PERFORMANCE EVALUATION OF GYPSUM BLOCK, TENSIOMETER AND MOISTURE SENSOR FOR SOIL MOISTURE CONTENT DETERMINATION

Abstract

Measurement of soil moisture has become very critical in irrigation water management studies especially in Africa. This research investigated the response of Tensiometer, Gypsum blocks and Sensor to changes in soil moisture and their appropriateness for irrigation scheduling on farms. Gypsum block was fabricated using a mould containing 15 cubicles of size (5x 4 x 2.5) cm in a wooden box frame, tensiometer irrometer – model SR was used to measure soil moisture tension. Arduino 1.8.7 board connected to two probes was used to build the soil moisture sensor. The three soil measuring devices were installed, calibrated and validated using the gravimetric method as the standard. The response of each moisture testing device was carried out using a t-test at a 5% significance level. The results revealed that the value of bulk density, field capacity, PH and electrical conductivity of the soil obtained were 1.463g/cm3, 20%, 5.50 and 0.034dS/m, respectively. The soil was sandy loam with percentage contents with sand, silt and clay in the
soil were 69.8%, 19.4% and 10.8%, respectively. The mean difference between the Gravimetric method, compared to gypsum, Tensiometer and Sensor, was 6.30, 3.95 and 3.02, respectively. It could be concluded that the Sensor used with the Adruino board measures moisture content more accurately than Gypsum and Tensiometer.