There exist crops like rice or sugarcane, which need more water than crops like beans and wheat. The table below gives some idea about the different seasonal water needs of the most important field crops.

Crop

 

Crop water need

(mm/total growing period)

Alfalfa 800-1600
Banana 1200-2200
Barley/Oats/Wheat 450-650
Bean 300-500
Cabbage 350-500
Citrus 900-1200
Cotton 700-1300
Maize 500-800
Melon 400-600
Onion 350-550
Peanut 500-700
Pea 350-500
Pepper 600-900
Potato 500-700
Rice (paddy) 450-700
Sorghum/Millet 450-650
Soybean 450-700
Sugar beet 550-750
Sugarcane 1500-2500
Sunflower 600-1000
Tomato 400-800

Approximate values of seasonal crop water needs. Source: FAO (1986)