Abstract
Evaporation from bare Sharpsburg s.c.l. was measured with precision weighing lysimeters at Mead, Nebr., during summer and fall, 1966. A number of drying cycles were included. Maximum daily evaporation was about 9 mm/day in August and about 3 mm/day in late October. The ratio E/Rn was frequently greater than unity especially when the lysimeters and a 1‐ha area surrounding them was visibly wet and the surface of the adjacent fields dry. A significant advectional contribution of energy in indicated. Nocturnal evaporation accounted for 10 to 50% of the total daily evaporation, the greater proportions occurring in fall. Dew was detected almost every morning. A maximum dew deposition of about 0.5 mm was measured. The Penman method yielded lower estimates of bare soil evaporation than did van Bavel's combination method. Both types of estimates varied from lysimetrically measured evaporation by from 3 to 50% on a daily basis.