Comprehensive evaluation of factors influencing selenium fertilization biofortification

Authors: HUANG, RUILIN - Nanjing University; Banuelos, Gary; FAROOQ, MUHAMMAD RAZA - University Of Science And Technology Of China; YANG, YULING - University Of Science And Technology Of China; SONG, JIAPING - Nanjing University; ZHANG, ZEZHOU - Nanjing University; CHEN, YOUTAO - University Of Science And Technology Of China; YIN, XUEBIN - Anhui Academy Of Agricultural Sciences; ZHAO, JIANRONG - Anhui Academy Of Agricultural Sciences; SHEN, LIDONG - Nanjing University

Submitted to: Frontiers in Plant Science
Publication Type: Review Article
Publication Acceptance Date: 2/2/2024
Publication Date: 3/6/2024
Citation: Huang, R., Banuelos, G.S., Farooq, M., Yang, Y., Song, J., Zhang, Z., Chen, Y., Yin, X., Zhao, J., Shen, L. 2024. Comprehensive evaluation of factors influencing selenium fertilization biofortification. Frontiers in Plant Science. 104:6100-6107. https://doi.org/10.1002/jsfa.13442.
DOI: https://doi.org/10.1002/jsfa.13442

Interpretive Summary: Currently, nearly one billion people worldwide have an inadequate intake of Se. Low Se content in soils and limits plant uptake and often leads to reduced Se concentrations in plant food and feed products, adversely affecting human or animal health. In agricultural ecosystems, applying Se-containing fertilizers to enhance the uptake of Se by crops and increase Se content in agricultural products is an essential strategy worldwide to combat address Se deficiencies. Successful Se biofortification strategies will, however, depend on soil physicochemical properties, e,g, soil pH, organic matter, soil type, as well as plant species and rate and mode of Se application (soil vs foliar application). In this overview, we constructed a meta-analysis dataset based on field experiments, including the topics crop Se content and yield. The objectives of this analytical study were to 1) systematically assess the dominant factors influencing Se fertilization for Se biofortification; and 2) investigate the relationship between Se fertilization rates on both Se content and yield. Our results indicated that plant type was the dominant factor influencing the Se content in agricultural products, followed by the rate of Se fertilization. The analyses demonstrated that foliar application yielded the highest Se biofortification followed by soil application or combined foliar and soil application. In Se biofortification, inorganic forms of Se were the most common sources of Se for Se fertilizers due to their low cost, ease of absorption by plants, and minimal soil residue. Future studies should include the monitoring of soil properties, microbial community composition, and atmospheric Se content with long-term use of Se fertilizers.

Technical Abstract: Dietary selenium (Se) deficiencies stemming from low Se concentrations in agricultural products threatens human health. Strategies to mitigate soils containing low levels of Se involve the use of Se fertilizers. While the application of Se-containing fertilizers can result in an elevated Se content in crops, there are key factors, e.g., soil type, mode of application, form of and rate of Se applied, crop species, that strongly effect this Se biofortification process; to what extent is not clear. To better understand the impact of these factors on the production of Se-enriched plant products, this study utilized a global meta-analysis based on a dataset collected from field experiments comprising 364 entries on Se content in agricultural products and 271 entries on their yield. We compiled a database encompassing all literature and data on crop responses related to Se content in agricultural products and yield after Se fertilization. Peer-reviewed articles were searched on Web of Science (https://www.webofscience.com), Dimensions (https://www.dimensions.ai), and China National Knowledge Infrastructure (https://www.cnki.net) up to July 2023, using keyword combinations like (selenium) AND (fertilizer* OR fertilization* OR exogenous) AND (soil* OR foliar). Random forest models and mixed effects meta-analyses revealed that plant types (i.e., cereals, vegetables, legumes, and forages) primarily influenced Se biofortification, with Se fertilization rates as the second most significant factor. The random forest model, which included variables like plant types, Se fertilization rates, methods and types of Se application, initial soil conditions (including Se content, organic carbon content, and pH), soil types, mean annual precipitation, and temperature, explained 82.14% of the variation in Se content and 48.42% of the yield variation in agricultural products. For the same agricultural products, the increase in Se content decreased with higher rates of Se fertilization. When the increase in Se content in agricultural products was negligible, the corresponding Se fertilization rates were 164, 103, 144, and 147 g ha-1 for cereals, forages, legumes, and vegetable crops, respectively. Conversely, while low Se fertilization rates enhanced yields, high rates led to a yield reduction, particularly in cereals. These findings highlight the benefit of using meta-analysis for creating more balanced and precise Se fertilization strategies that optimize Se biofortification to benefit human and animal health and minimize the risk of yield reduction.