Agronomic Biofortification of Vegetable Crops with Selenium and Iodine: A Review

Currently, there is a widespread deficiency of certain trace elements, which leads to an array of disorders/diseases in plants, animals and humans. Finding novel solutions to this problem is critical for the agro-chemical approach to food production. Numerous studies have been conducted on the fertilisation of plants with micronutrients; however, a systematic review summarising the most recent findings on the agronomic biofortification of vegetable crops with trace elements is still lacking. This work is a systematic review which compares the results of different doses and formulations of fertilisers with the yield performance and micronutrient content of edible parts of vegetable crops, with a focus on their enrichment with selenium and iodine in particular. These elements constitute a distinct group of micronutrients as, in contrast to other micronutrients like iron, zinc, manganese, copper etc., they are administered to plants in anionic form: selenium as selenite (SeO32-) and selenate (SeO42-), and iodine as iodide (I-) and iodate (IO3-). This review examines the importance of optimised fertilisation in the biofortification of Se and I, with a special emphasis on effectively mitigating hidden hunger. It may be argued that using an integrated biofortification strategy for Se and I is preferrable, but future perspectives with respect to research and development are required.