Water Needs
The total amount of water that a corn crop needs during the growing season may vary from 20 to 30 inches depending on factors such as weather conditions, plant density, fertility, soil type and days to maturity. In most seasons, the amount of water needed will be about 20 to 24 inches. The inches of irrigation water required will vary depending on the beginning soil moisture and the rainfall received during the growing season. The irrigation system needs to be capable of providing 12 to 16 inches of irrigation water to assure a good yield potential.
Moisture stress anytime after planting can affect plant development and reduce yield potential. The amount of yield loss is dependent on the growth stage of the corn when moisture stress occurs. Table 3-1 shows the general relationship of potential yield reduction due to moisture stress at different growth stages