Use of Constant Level Jain Evaporimeter in Scheduling Irrigation

Abstract

The "Constant level Jain Evaporimeter" described in the paper can be successfully used to measure the evaporative demand of an atmosphere and hence for scheduling irrigation. In this equipment the level of evaporating surface is constantly maintained at a depth of 4 cm in a can of 17.4 em diameter and the water supply is maintained from a bottle connected with a tube. As soon as the water evaporates, It is refilled with water in the bottle and hence the amount of water evaporated can be accurately read directly from graduation in the bottle. A relationship of 1.4-1.5 is obtained between the values of this evaporimeter and the U. S. Pan Evaporimeter. The equipment is simple, can be easily handled by a skilled farmer, is economical (approximately costing Rs 45/- each) and is a better representative of evaporative demand.