Agronomic iodine biofortification of leafy vegetables grown in Vertisols, Oxisols and Alfisols

Ligowe, Ivy Sichinga; Bailey, E. H.; Young, S. D.; Ander, E. L.; Kabambe, V.; Chilimba, A .D.; Lark, R. M.; Nalivata, P. C.

Abstract

© 2020, The Author(s). Iodine deficiency disorders (IDD) in sub-Saharan African countries are related to low dietary I intake and generally combatted through salt iodisation. Agronomic biofortification of food crops may be an alternative approach. This study assessed the effectiveness of I biofortification of green vegetables (Brassica napus Land Amaranthus retroflexus L.) grown in tropical soils with contrasting chemistry and fertility. Application rates of 0, 5 and 10kgha−1I applied to foliage or soil were assessed. Leaves were harvested fortnightly for ~ 2months after I application before a second crop was grown to assess the availability of residual soil I. A separate experiment was used to investigate storage of I within the plants. Iodine concentration and uptake in sequential harvests showed a sharp drop within 28days of I application in all soil types for all I application levels and methods. This rapid decline likely reflects I fixation in the soil. Iodine biofortification increased I uptake and concentration in the vegetables to a level useful for increasing dietary I intake and could be a feasible way to reduce IDD in tropical regions. However, biofortification of green vegetables which are subject to multiple harvests requires repeated I applications.

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2020
• Online Publication Date: Sep 23, 2020
• Publication Date: 2021-01
• Deposit Date: Sep 14, 2020
• Publicly Available Date: Sep 23, 2020
• Journal: Environmental Geochemistry and Health
• Print ISSN: 0269-4042
• Electronic ISSN: 1573-2983
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 43
• Pages: 361-374
• DOI: https://doi.org/10.1007/s10653-020-00714-z
• Keywords: Iodine biofortiofication; Brassica napus L; Amaranthus retroflexus L; Vertisols; 16 Oxisols; Alfisol
• Public URL: https://nottingham-repository.worktribe.com/output/4903395
• Publisher URL: https://link.springer.com/article/10.1007%2Fs10653-020-00714-z