Reducing the impact energy of sprinkler droplets through irrigation management should minimize surface soil
aggregate breakdown and seal formation while maintaining infiltration rates. From 1997 through 1999 in southern
Idaho, we quantified sprinkler droplet energy effects on infiltration and near-surface hydraulic conductivity
measured under tension after crop stand establishment. The treatments were droplet energies: 0 or 7 J kg - (0 or
7 J m - min-1), produced with a low-pressure, lateral-move irrigation system. After planting sugarbeet (Beta
vulgaris L.) into a Portneuf silt loam (Durinodic Xeric Haplocalcid) and irrigating 2-3 times, we used tension
infiltrometers to measure unconfined (three-dimensional) infiltration rates through undisturbed soil surfaces at three
supply potentials. Reducing droplet energy significantly increased steady-state infiltration, averaged across years,
at supply potentials of -20 and -40 nun and kept soil surfaces rougher with less aggregate breakdown. Pores with
diameters between 0.75 and 1.5 mm were most affected by droplet energy
