We took an approach of soil sampling and preparation that was
considered to exclude mycorrhizal fungi and to minimize the
disturbance on soil microbial community (Chen et al., 2014). In
September 2013, eighty soil cores (2.5 cm diameter 10 cm height)
were randomly collected from each of the three field plots of the
conventional cash cropping system and pooled to form three
composite soil samples. Soil was sieved (