Characterization of paddy soil compaction based on soil apparent electrical conductivity zones

Abstract

Soil apparent electrical conductivity (ECa) is one of the most common and frequently used measurements to determine field soil variability, especially for precision farming. Soil cone index (CI) is a measure of soil compaction that poses a big challenge for water management in poorly drained soils. The soil compaction affects the root penetration and development of the rice plant. The purpose of this study was to characterize the CI within the ECa zones for a Malaysian paddy soil. The study of soil compaction and ECa was conducted on silty clay paddy soil at Sawah Sempadan, Tanjung Karang, Selangor (latitude 3°35'' N and longitude 101° 05'' E). Measurement of ECa and CI were done using Veris 3100 and hand-operated soil cone penetrometer, respectively. The deep ECa (ECad) was compared to the minimum, mean and maximum CI and also within ECad zone. The maximum CI was found at 0.147 MPa with average maximum at 0.081 MPa. The results indicate that the hardest layer exists at a depth of 10 to 20 cm. ECad in Zone 2 (50 to 100 mS m-1) showed that the CI values have the highest significant negative correlation with ECad. The significant correlation of ECad and soil cone index was found at mid range of the soil ECad. Keywords: Zone delineation, paddy field, cone index, regression.