Department of Agricultural Chemistry, Soil Science and Biochemistry, Orissa University of Agriculture & Technology, Bhubaneswar, Orissa, 751 003.
Present addresses: * Department of Agriculture and Food Production, Orissa, Bhubaneswar-751001.
Hydrological properties of a Typic Haplustult were studied in the course of field calibration of a CPN neutr9n hydroprobe. Installation of Hg-H2O tensimeters allowed the in situ determination of soil water characteristics as well as the K(θ) based on the drainage characteristics of an evaporating profile. Calibration curves (count ratio versus volumetric water content. θ) stemmingfrom the hydroprobe data using access pipes made of pluminium, iron and PVC indicated that the last one may be used as a substitute for the first (i.e. aluminium) as neutron access pipe material. Calibration relation formulated for baresoilprofile wasprone toover-predict ‘0’ under cropped situations owing possibly to the presence of higher concentration of root biomass in the latter. K(θ) based on the tensiometer method was shown to be more realistic than that formulated according to Libardi et al.'s (1980) method.
Nutron hydroprobe, Hg-H2O tensiometer, hydraulic conductivity, soil water characteristics
