When drip irrigation is used, water is added, drop-wise, to soils for long periods of time. Wetting occurs laterally in the soil up to a half metre or more from the drip nozzle.

(a)   Why does all the water not drain straight downwards in the soil profile?

(b)  In which soil is lateral movement likely to be faster -a clayey soil or a sandy soil?

(c)   Give reasons for your answer at (b).

(d)  Is moisture moving from low water potential to high water potential or the reverse?

pur-new-sol