2.2. Experimental design
Laboratory scale incubation studies were conducted for 94 days
on soil conditioned with three different treatments (T1 to T3), for
each amendment tested. Representative soil samples (about 50 g)
were mixed with each compost (CES and CWES) at three rates:
T1 = 2.5 g, T2 = 5 g and T3 = 15 g (air dried basis). In the case of ES
amendment, equivalent rates to CES_T1 to T3 in terms of neutralizing
capacity (equivalent CaCO3) were tested. Thus, the application
rate to soil was ES_T1 = 1.6 g, ES_T2 = 3.2 g and ES_T3 = 9.5 g (air
dried basis). For each treatment and control samples, three replicates
were performed (i.e. twelve experiments were followed
during the incubation period). The moisture of all mixtures was
adjusted to 65% of their water holding capacity (WHC) and maintained
during each experiment by adding distilled water. Incubation
tests were carried out in 1 L closed mason jars, in dark
conditions, while keeping the temperature at 25 C.