Calibration of Inductive Electromagnetic Probe for Assessing Soil Salinity in Vertisols of Malaprabha Command, Karnataka

摘要

Soil salinity assessment with respect to area, severity and temporal and spatial variability is necessary for the reclamation, especially in canal commands, where salinity is one of the major constraints in crop production. Conventionally, diagnosis of soil salinity involves measurement of electrical conductivity of soil solution or saturation extract requires extensive soil sampling and also time-consuming. Moreover, such sampling strategies disturb soil which is undesirable for repetitive measurements. During the last two decades, many new techniques have been developed (Rhoades and Ingvalson 1971; Rhoades 1976). Advanced method of using inductive electromagnetic (IBM) technique is more convenient, faster and reliable as it does not require drawing and preparation of soil samples. The IEM technique has been used worldwide for surveying the salt-affected soils by many workers (Carwin and Rhoades 1982; Banerjee et dl. 1998; Kuligod et al. 2001). But standard calibrated equations developed elsewheregenerally do not hold good for all the soils. Hence, an attempt was made to calibrate inductive electromagnetic meter for assessing soil salinity in Vertisols of Malaprabha command by developing depth-specific co-efficients relating saturated paste electrical conductivity (ECe) of different soil depth intervals to IEM readings.