2.4 Soil carbon pool
In each treatment, three soil profiles were dug to a depth of 100 cm.
Soil samples were taken at
intervals of 10 cm to determine their C content and bulk density, which
was measured for three replicates from each depth. A pooled sample from
three individual sampling points at each depth yielded a homogeneous
sample, which was ground fine enough to pass through a 2 mm sieve after
removing roots and other debris, air-dried in the laboratory, and then
stored in sealed polythene bags for determining soil C content.