USING ELECTRICAL RESISTIVITY METHOD AND LABORATORY MEASUREMENTS IN ASSESSING SELECTED SOIL PROPERTIES ON THE GROWTH OF CUCUMBER (Cucumis sativus)

Abstract

Randomized Complete Block Design (RCBD) field experiment was carried out on agricultural farm land at Teaching and Research Farm of the Federal University of Technology, Akure. The research is aimed at monitoring soil water dynamics and evaluating the impact of soil properties such as moisture, electrical conductivity, salinity and pH, on the growth and yield of Cucumber (Cucumis sativus) using 2D-Electrical Resistivity Tomography (ERT) method. Geophysical survey was conducted using Ohmega resistivity meter on humus soil packed inside six wooden boxes each of dimension 3.6 m × 0.6 m × 0.45 m, while Dipole-dipole array with electrode spacing of 0.1, 0.2 and 0.3 m was adopted for the measurement. A total of forty-eight (48) soil samples were collected from the study site and were analyzed in the laboratory with the aid of Electric oven, Jenway conductivity meter, Hanna salinity meter and pH meter, while the soil samples were limited to the top soil within 0.1 m depth. Data collected on plants includes; vine length measured at 2 weeks, 3 weeks and 4 weeks after planting, number of fruits per plant, fruit length, and fruit diameter which were subjected to analysis of variance (ANOVA). The inverted electrical soil resistivities range between 276 - 492, 112 - 202, 12 – 60 and, 64 - 207 ohm-m, at the pre-planting, planting, flowering and harvesting stage of the crop respectively. The laboratory determined soil parameters range between 10 – 70 %, 180 – 600 s/m, 180 - 700 ppm and 7.5 - 9.3 for moisture, conductivity, salinity and pH respectively. The inverted soil resistivities and laboratory soil parameters were correlated using regression analysis from which mathematical models were generated and interpreted accordingly. This study has demonstrated that geophysical applications can enhance agricultural practices and reduce cost by providing a fast and cost effective means of monitoring soil properties for high yields.