Department of Agricultural Engineering, Indian Institute of Technology, Kharagpur, West Bengal
*Present addresses: Water Management Project, Mahatma Phule Krishi Vidyapeeth, Rahuri, Ahmednagar district, Maharashtra
**Present addresses: Water and Land Management Institute, Aziz Mansion, P.B. No. 81, Padampura, Aurangabad-431 001, Maharashtra
Water loss in a swelling black clay soil as influenced by potential evaporative demand and the induced shrinkage cracks was evaluated at 25, 50, 75 and 110 m bar of stress. Shrinkage cracks were simulated by adopting a technique of V shape aluminium model and a lever system in PVC cylinders using porous plate at the bottom. Soil temperature and moisture distribution were measured using temperature recorder and tensometric technique. The normal rate of water loss from soil surface at saturation (8.5 mm/day) decreased to considerable extent (3.5 mm/day) as the soil moisture stress increased (110 m bar). Water loss through induced cracks concomitantly increased (5.0 to 5.9 mm/day at about saturation and 1.2 to 2.3 mmjday at 110 m bar stress) with increase in the surface area of the cracks exposed to the atmosphere (90 to 200 cm2).
Soil moisture stress, induced shrinkage crack, evaporative demand, vapour flux
