Abstract

Continuous use of diammonium and single super phosphates having traces of cadmium (02 to 200 ppm) is contaminating agricultural soils. In order to assess the levels of cadmium contamination of semiarid Indo-gangetic soils in Yamuna ravines and crop quality, a green house study was conducted in oat crop with four levels (mg kg -1 of soil) each of cadmium (Cd o : 0, Cd 1 : 12.5, Cd 2 : 25.0 and Cd 3 : 50.0) and sulfur (S o : 0, S 1 : 12.5, S 2 : 25.0 and S 3 : 50.0) in factorial randomized block design. Results revealed that increasing Cd doses significantly decreased grain (3.98 g pot -1 in Cd 0 to 2.50 g pot-1 in Cd 3 ) and straw (5.59 g pot -1 in Cd 0 to 4.07 g pot -1 in Cd 3 ) yields. Increasing Cd doses significantly enhanced Cd (g pot -1 ) in biological harvest (2.7 in Cd 0 to 7.3 in Cd 3 in grain and 5.8 in Cd 0 to 23.2 in Cd 3 in straw) and decreased S (g kg -1 ) in biological harvest in treatment (0.29 in Cd0 to 0.21 in Cd 3 in grain and 0.18 in Cd 0 to 0.13 in Cd 3 in straw) and interactions (0.32 in Cd 0 to 0.18 in Cd 3 x S 0 x S3 in grain and 0.20 in Cd 0 x S 3 to 0.11 in Cd 3 x S 0 in straw), over various S doses. Thus, Cd inhibited plant biochemical processes and metabolism and enhanced sink and consumption of reduced sulfur as indicated by lower S in grain and straw. Increasing S enhanced S (mg kg -1 ) in grain (0.21in S 0 to 0.28 in S 3 ) and straw (0.14 in S 0 to 0.17 in S 3 ) under varying Cd stress confirming mitigation in uptake, accumulation and toxicity of Cd as well as higher S translocation from aerial parts to grain. Cd recovered in biological harvest in Cd0 revealed that semi arid alluvium soils are already considerably cadmium polluted. Singnificantly higher productivity (g pot -1 ) was recorded in Cd 0 and S 2 for grain and straw i.e. 3.98 and 3.59 and 5.99 and 5.52, respectively. Among interactions, singnificantly higher productivity (g pot -1 ) was recorded in Cd 0 x S 2 for grain (4.34) and straw (6.51). Cd 3 x S 3 produced minimum grain (2.37 g pot -1 ) and straw (4.20 g pot -1 ) yield. Thus, S partially mitigated Cd stress upto 25 mg kg -1 of soil and also maintained higher oat yields.

Keywords: Cadmium, Oats, Food chain contamination, Food quality, Heavy metal, Health hazard.