Selenium in soils and crops

Abstract

Edible crops are the foundation of food chains for humans and livestock. However, although selenium (Se) is an essential nutrient for animals, it is not required by plants. Selenium is acquired and metabolised by plants because of its chemical similarity to sulphur. This chapter first describes how geology, climate and soil chemistry affect the concentration and forms of Se in soils and, consequently, their uptake by crops. It then describes the metabolism of Se in plants and the prevalent chemical forms of Se in edible crops, particularly those contributing substantially to human nutrition, such as cereals, potatoes, alliums and brassicaceous vegetables. Finally it describes strategies to biofortify edible crops with Se using agronomic approaches, such as the application of Se fertilisers, and how these might be complemented by selecting or breeding genotypes with a greater ability to acquire Se and distribute it to edible tissues.