Soil respiration
(CO2 measurement) was done repeatedly on 20 g
portions of soil per treatment in 100 mL pyrex glass
flasks. The flasks were covered with aluminium foil
and secured with a septum. During sampling, the
headspace of each flask was equilibrated with the soil
atmosphere by pumping with a 10 mL syringe. There
after, 100 μL of atmospheric air was injected and the
same volume of gas removed for the CO2 analysis using
a Nitrogen carrier with a flow rate of 50 mL/min. CO2
evolution was measured by a Beckman Model 865
infrared gas analyzer