Agronomic biofortification can be used to alleviate the deficient intake of selenium (Se) and zinc (Zn) by livestock. These two essential micronutrients for human and animals play an important role in many physiological functions and biological processes. The aim of the present study was to evaluate the suitability of forage peas, crop with an increasing importance as plant protein source, to be biofortified with a combined treatment of Zn (as ZnSO 4-7H 2 O) and Se (as Na 2 SeO 4). A 2-year field experiment was established in southern Spain under semiarid Mediterranean conditions, by following a split-split-plot design. The study year (2017/2018, 2018/2019) was considered the main-plot factor, soil Zn application (50 kg Zn ha −1 , nil Zn) as a subplot factor, and foliar application (nil, 10 g Se ha −1 , 8 kg Zn ha −1 , 10 g Se ha −1 + 8 kg Zn ha −1) as a sub-subplot factor. The combined application of 50-kg soil Zn ha −1 and the foliar application of 10 g Se ha −1 + 8 kg Zn ha −1 was the most effective treatment to increase the concentration in forage of Zn and Se, 4-fold and 5-fold, respectively, as well as the Zn bioavailability, forage yield (close to 30%), and crude protein (~8%). Thus, forage peas could be considered a very suitable crop to be included in biofortification programs under Mediterranean conditions with Zn and Se as target minerals.

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.