Agronomic Selenium Biofortification in Field Crops: Soil-Plant-Human Pathways, Fertilizer Strategies, and Nutritional Outcomes
Aniket H. Kalhapure *
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Amit Kumar
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Arun Kumar
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Narendra Singh
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Gurusharan Panwar
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Dinesh Sah
Department of Agronomy, Banda University of Agriculture & Technology, Banda, U.P., India.
Anand Kumar Chaubey
Department of Soil Science, Banda University of Agriculture & Technology, Banda, U.P., India.
Shyam Singh
Krishi Vigyan Kendra, Banda University of Agriculture & Technology, Banda, U.P., India.
*Author to whom correspondence should be addressed.
Abstract
Selenium (Se) is a vital micronutrient for human and animal health. Yet, its uneven distribution in soils leads to widespread dietary deficiencies, particularly in regions reliant on crops from Se-poor areas. Agronomic biofortification can enhance crop Se content through targeted agricultural practices and offers a sustainable, cost-effective strategy to combat this “hidden hunger.” This review integrates current knowledge on the soil-plant-human Se continuum, factors influencing Se bioavailability, and the comparative effectiveness of inorganic (selenate, selenite) and organic Se sources. The chemistry, mobility, and transformations of Se in soils are discussed alongside the benefits and limitations of soil application, foliar sprays, seed priming, irrigation-based delivery, and microbial-assisted biofortification. Case studies, including Finland and China’s nationwide programme, demonstrate the feasibility of large-scale implementation. Evidence shows that optimised Se biofortification can substantially increase grain Se concentrations, improve nutritional quality, and enhance stress tolerance, though benefits follow a narrow dose-response curve. Integration with soil and plant testing, nutrient management, and environmental safeguards is essential to avoid toxicity and ensure long-term sustainability. Agronomic Se biofortification, when adapted to local conditions and supported by policy frameworks, represents a viable global strategy to improve public health by closing the selenium intake gap.
Keywords: Selenium biofortification, agronomic fortification, staple crops, micronutrient enrichment, crop physiology, abiotic stress tolerance, grain quality, human nutrition