Developing a Sustainable Phytomanagement Strategy for Excessive Selenium in Western United States and India

Abstract

Phytomanagement technology is recognized as an inexpensive and environmental friendly strategy for managing natural-occurring selenium (Se) in soils and in poor quality waters. Multi-year field and greenhouse studies were conducted with different plant species in California, USA and Punjab, India under high Se growing conditions. Some of the plant species included; canola (Brassica napus), mustard (B. juncea), broccoli (B. oleracea), spearmint (Mentha viridis), sugarcane (Saccharum officcinarum), guar (Cyamopsis tetragonoloba), wheat (Triticum aestivum), and poplar (Populus deltoides). California soils had a sodium-sulfate-dominated salinity between 6–10 dS m⁻¹, while Indian soils had a calcium carbonate salinity less than 1 dS m⁻¹. Results demonstrated that high sulfate conditions reduced plant Se accumulation more than 100× in Californian grown plants compared to Se accumulation in Indian grown plants. Tissue concentrations generally did not exceed 10 and 200 mg kg DM⁻¹ in leaves of plants grown in California and India, respectively. At these plant concentrations, Se phytomanagement is more effective in Indian soils than in California soils. Successful management of Se by plants requires selecting crops or crop rotations that are tolerant of the soil condition and identifying and creating new viable Se-enriched products.

KEY WORDS:

• phytoremediation
• plants
• flowers
• volatilization