Question

The following data were recorded from an irrigated field:

Based on these data, the net irrigation requirement per metre depth of soil will be

• A. 75 mm
• B. 125 mm
• C. 50 mm
• D. 25 mm

Answer 1

The correct option is C 50 mm

The readily available moisture
$=0.5\times (20-10)=5\%$

Deficiency due to the fall of moisture is
$=\frac{{\gamma }_d}{{\gamma }_{\omega }}\times d\times \text{readily available moisture}$

$=\frac{1500}{1000}\times 1000\times 0.05=75mm$

25 mm depth of water is available from precipitation so net irrigation needed is 75 - 25 = 50 mm