Characterizing the origin of organic selenium in seleniferous soil of Punjab, India

Occurrences of seleniferous soil and associated selenium (Se) toxicities to plants, animals, and humans are environmental concerns in Punjab, India. These Se toxicities are attributed to the high Se uptake and accumulation in edible plants. Our two experiments at the FAME-UHD beamline investigated the temporal dynamics of Se speciation in the topsoil and different parts of the rice and wheat plants over a rice-wheat crop rotation season in a seleniferous agriculture plot, where rice crop residue had been incorporated for four years. Results showed that organic Se is the dominant Se reservoir in this soil, and plants primarily uptake Se from the soil as organic Se. However, the origin of this organic Se in soil could not be identified conclusively due to the limited number of sample analyses. Therefore, we propose further beamtime at the FAME-UHD beamline for the speciation of Se in additional soil samples.