Chemical and microbial soil analyses
From each plot, soil samples were taken in the soil layers
0–10 cm and 10–20 using a 30 mm wide soil auger during the
last week of May 2011. Ten soil cores from the individual soil
depths were pooled and homogenized to a composite sample, further
sieved to 5 mm and stored at 4 ◦C until subsequent analyses.
Subsamples were taken and dried at 105 ◦C for two days to determine
soil moisture content. Soil chemical analyses were performed
using air-dried crushed soil samples. Soil organic carbon (Corg) was
measured after wet oxidation of 1 g dry soil in 20 ml concentrated
H2SO4 and 25 ml 2MK2Cr2O7 according to Swiss standard protocols
(FAL et al. 1996). Total N content was determined with an elemental
analyzer (Eurovector, Milan, Italy) using high catalytic combustion
on oven-dried bulk soil samples.