Main Purpose and Description
Catch and hold runoff water in 1m deep pits that are filled with organic matter such as compost or manure. The organic matter makes the soil more fertile and holds the water to stop it being lost to the air (evaporating) or just draining through the soil.
Further information can be found in the WRC Resources Library
WH&C Vol 2, Part 1 (T: Pp124, 151-152 & H), AWHGS (CS: Chap 5, P.22-26)