Correct Answer - Option 3 : Delta
Explanation:
Delta is the total depth of water (generally in cm) needed by a crop during the entire base period and is denoted by Δ.
Ex: If 10 cm depth of water is required in each watering of rice and there are 12 such watering then the delta of the crop is = 12 × 10 = 120 cm
Important point:
Duty:
(i) It is the relationship between the volume of water available to the area which can be irrigated for a particular crop.
(ii) The area which can be irrigated by 1 cumec of discharge when it is available throughout the base period is called duty of the crop.
Base period:
This is the total period for which watering is applied to the field. It starts from first watering just before sowing the crop to the last watering just before the harvesting.
Crop ratio:
(i) Crop ratio is the ratio of the area of land irrigated during the two main crop seasons (i.e. Rabi and Kharif).
(ii) It is also called the Rabi-Kharif ratio.
