Effect of biochar, derived from unfertilized
dates, on the immobilization of Cd and Ni, in a sandy
loam alkaline soil, was investigated. The biochar was
applied to the soil columns at the rate of 0.5, 1, and 2 %
(w/w) artificially polluted with 10 mg kg−1 Cd and
100 mg kg−1 Ni. After 1 month incubation of soilbiochar
mixture under ambient conditions, the soil bulk
density was reduced by 0.19 g cm−3 as compared with
no biochar additionwith increase in soil pH. A reduction
of 53%in the NH4NO3-extractable soilNi was recorded
as compared with the corresponding control without
biochar addition. After incubation, the water-soluble
Ni and NH4NO3-extractable soil Cd and Ni contents
were significantly lower in all the biochar treatments
than the control. A reduction of 53 % in the NH4NO3-
extractable soil Ni was recorded as compared with the
corresponding control. The biochar content separated
from the incubated soil showed low concentrations of
NH4NO3-extractable Cd and Ni. The total Ni and Cd
contents recovered from biochar samples after incubation
were 35.2 and 3.7 mg kg−1, respectively. Their
contents in soil were substantially reduced by the incorporation
of biochar amendment (114 to 57.2 mg kg−1
Ni, 9 to 5.6 kg−1 Cd) as compared with the no-biochar
control. Therefore, addition of the biochar improved the
soil physical properties and succeeded in immobilizing
the studied metals.