Drum culture technique is used to determine WR of 

Solution

Drum culture technique is used to determine water requirement of lowland rice. In this method, four drum of size 50×50×50 cm are taken i.e. A, B, C and D. A and B have bottom while C and D are without bottom. All the drums are embedded in soil leaving 20 cm above soil surface. Rice is transplanted in drum A, C & D. and rice seedlings without roots are planted in drum B and the data on percolation, evaporation, ET, transpiration and effective rainfall is obtained.