Department of Soil Science and Agricultural Chemistry, Orissa University of Agriculture and Technology, Bhubaneswar, Orissa, 751 003
*Present address: All India Coordinated Research Project for Dryland Agriculture, OUAT, Bbubaneswar, Orissa. 751003
Mercury-water tensiometers were employed to determine in situ hydraulic conductivity, K (θ), based on both the draining profile and the evaporating profile methods. Soil water content, θ, was inferred from laboratory determined soil water characteristics, θ (h), on undisturbed soil cores taken from eight soil depths of the field profile. The K(θ) values derived from the two in situ methods were found to agree quite closely, though, the computed ones based on the modified Millington and Quirk model were good only in the case of 15 and 30 cm soil depths, which were of coarser texture. Observations pertaining to the evaporating profile also enabled the determination of soil water evaporation rate with time. Over a period of 12 days during May, the cumulative evaporative flux was observed to be 1.9 cm derived chiefly from the top 30 cm of the profile.
Soil water characteristics, hydraulic conductivity, draining profile, evaporating profile, evaporation rate, Darcy's law
