Abstract
We evaluated four organic amendments for their effect on AB-DTPA extractable Ni with time in an incubation
study. Organic amendments viz. farm yard manure (FM), poultry manure (PM), press mud (PrM) and activated
carbon (AC) were applied onto soil @ 2 and 4 % on air-dry weight basis. Soil samples were taken after 30- and
60-days incubation. Soil-applied amendments differed significantly for soil pH1:10, OM, AB-DTPA extractable Ni
and other metals like Cu, Zn, Mn and Cd. Amendments increased OM in post-incubation soil and increase was
maximum was with AC4 (AC @ 4 %) after both periods. Incubation time decreased OM, decrease being maximum
(41 %) and minimum (5 %) with FM4 (FM @ 4 %) and PrM2 (PrM @ 2 %), respectively. Maximum pH was with
AC4 and AC2 (AC @ 2 %) while it was minimum with PrM4 (PrM @ 4 %). The FM and AC decreased Ni in soil
after 30-days incubation but this effect diminished after 60-days incubation. In general, Ni and other metals
decreased in soil with time.
