Performance of castor in heavy metal polluted soils under the treatment of various decontaminants

Abstract

In order to find out the performance of castor under decontaminant treated heavy metal polluted soils, an experiment was conducted at Students Farm, College of Agriculture, PJTSAU, Rajendranagar, Hyderabad, during kharif 2016 to study the performance of castor in heavy metal polluted soil under the treatments of various decontaminants (various dosages of phosphorus as well as, quick lime). The dry matter before flowering, and stalk yield at harvest of castor varied from 429 to 516, 1460 to 1758 kg/ha, respectively. Among the different decontaminants highest dry matter yield and stalk yield (516 and 1758 kg/ha at before flowering and harvest) and seed yield (1720 kg/ha) was obtained in T5 (RDF+CaO @ 2 t/ha), which was significantly superior over all other treatments and on par with T4 (RDF+CaO @ 1 t/ha), and per cent increase over RDF was 20.41 and 23.56, respectively for stalk, and seed yield of castor. Decontamination treatments had reduced the mean Pb, Cd, Ni and Co contents of castor to 4.51, 0.65, 0.95 and 0.63 mg/kg, and increased mean uptake to 7.62, 1.17, 1.69 and1.09 g/ha respectively, for Pb, Cd, Ni and Co in seed at harvest. The  Pb, Cd, Ni and Co contents of soil after harvest of the castor crop ranged from 17.11, 0.79, 1.89 and 1.22 mg/kg in the reference control and decreased to 14.60, 0.68, 1.67 and1.02 with RDF+CaO @ 2 t/ha treatment. The reduction in Pb, Cd, Ni and Co concentration in post-harvest soil was more due to Cao at different levels when compared to high phosphorus.