Cadmium Contamination of Agricultural Soils in Catchment of Yamuna Ravine: Response of Sulfur on Yield and Quality of Oat

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 (Cdo: 0, Cd1: 12.5, Cd2: 25.0 and Cd3: 50.0) and sulfur (So: 0, S1: 12.5, S2: 25.0 and S3: 50.0) in factorial randomized block design. Results revealed that increasing Cd doses significantly decreased grain (3.98 g pot-1 in Cd0 to 2.50 g pot-1 in Cd3) and straw (5.59 g pot-1 in Cd0 to 4.07 g pot-1 in Cd3) yields. Increasing Cd doses significantly enhanced Cd (g pot-1) in biological harvest (2.7 in Cd0 to 7.3 in Cd3 in grain and 5.8 in Cd0 to 23.2 in Cd3 in straw) and decreased S (g kg-1) in biological harvest in treatment (0.29 in Cd0 to 0.21 in Cd3 in grain and 0.18 in Cd0 to 0.13 in Cd3 in straw) and interactions (0.32 in Cd0 to 0.18 in Cd3 x S0 x S3 in grain and 0.20 in Cd0 x S3 to 0.11 in Cd3 x S0 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 S0 to 0.28 in S3) and straw (0.14 in S0 to 0.17 in S3) 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 Cd0 and S2 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 Cd0 x S2 for grain (4.34) and straw (6.51). Cd3 x S3 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.