5 days later, after the stabilization of Pb in the soil.
Equivalent amounts of urea-nitrogen were applied to all treatments
in order to avoid the undesirable effects of N as Pb(NO3)2. To
balance NO3 in the control treatment, 292.7 mg Urea kg−1 soil was
added to have the same amount of total N compared with 1000 mg
Pb kg−1 soil treatment. In the other Pb treatments, we followed the
same procedure to replace the comparable amount of NO3.
The AMF R. clarus soil inoculums from the Glomales bank of
UNIPAR Access No. 10 (Lermen et al., 2015; Urcoviche et al., 2015)
were applied to the upper third of each pot designed for the AMF
treatment. For each pot, 200 g soil inoculum containing 500 spores
and infective propagules was added. The control treatments used
100 mL ofthefilteredsoilinoculums (100 g soilinoculum L−1 deionized
water). Thus, we only have the effect of the inoculated AMF.
All treatments were fertigated every two days with a half concentrationofthe
solutionbyHoaglandandArnon,(1950), exceptfor
N, which was already applied as Pb(NO3)2 and urea atthe beginning
of the experiment.