remained in place until the end in 15 December 2010. In the Lmng
plots, collars were necessarily removed just before tillage and were
replaced in the same locations at least 24 h prior to any measurement
being made. In the Amng plots collars were placed within the
understorey with any vegetation inside being clipped very short to
ensure that only soil respiration was measured and to avoid errors
from differences in volume within the gas chamber. Soil CO2 efflux
measurements were made every two or three weeks from January
through to December. On each occasion, measurement starting at
11 a.m. and was always completed by 1 p.m.