1. Some have been fitted with frozen tanks of carbon dioxide to be ejected into the sky to form artificial rain clouds.

2. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1/2 yr with 125 mm yr−1 artificial rain in addition to natural precipitation

3. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1/2 yr with 125 mm yr−1 artificial rain in addition to natural precipitation