Combined zinc and selenium biofortification in field peas under Mediterranean conditions

Abstract

The intake of zinc (Zn) and selenium (Se), two essential micronutrients, is deficient worldwide both in humans and in livestock. This deficiency could be alleviated through agronomic biofortification, a practice that increases their concentrations in edible parts through mineral application. The aim of the present study was to evaluate in a 2-year field experiment (2017/18, 2018/19) the suitability of field peas to increase Zn and Se grain concentration after soil Zn application (50 kg Zn ha−1; no Zn) and foliar application (0; 10 g Se ha−1; 8 kg Zn ha−1; 10 g Se ha−1 + 8 kg Zn ha−1). Zinc bioavailability (estimated by the molar ratio phytate/mineral), grain yield, thousand grain weight, grain crude protein and mineral status (magnesium, calcium and iron) of the grain were also evaluated by following a split-split plot design. For biofortification purposes, the combined foliar application of Zn (8 kg Zn ha−1) and Se (10 g Se ha−1) increased Zn and Se concentrations in grain by around 30% and 73%, respectively, as well as Zn bioavailability, decreasing the molar ratio phytate/Zn by 30%. The additional soil application of 50 kg Zn ha−1 increased grain yield by 16%. Other nutritional parameters, such as content of protein or other essential minerals, were also improved (or at least not negatively affected) by the combined application of Zn and Se. All of these aspects evidenced the suitability of field peas for use in biofortification programmes through the simultaneous application of Zn and Se, which might also cheapen application costs.