Nitrogen fertilisation affected zinc and selenium biofortification in silage maize

Abstract

Context Biofortification of forage crops has become even more important, due to the improvement in livestock nutrition, but it has also had an indirect positive impact on the human diet. Aim This study investigated the effect of nitrogen and microelement (Zn and Se) fertilisation on yield and on the microelement composition of maize (Zea mays L.) silage. Methods Two field experiments were conducted using a two-factorial split-plot design with nitrogen fertilisation in three doses: 0, 120, 180 and 240 kg N/ha. The first experiment included foliar Zn fertilisation as the second factor (0, 1.5 kg Zn/ha and 1.5 kg Zn/ha + urea solution). The second experiment studied the effect of Se (10 g Se/ha). Key results Nitrogen fertilisation increased biomass yield, Cu and Mn concentration in silage maize. Application of Se and Zn did not affect the biomass yield, but it had a positive effect on Se and Zn concentration in plants. Zn and urea application in combination proved to be more efficient in increasing Zn concentration in plants when compared to Zn applied alone. Conclusions Nitrogen and fertilisation with Zn and Se can be a good tool in fodder plant biofortification because their application led to a yield increase (Zn), but at the same time to an improvement in the mineral composition of maize biomass, with essential elements (Zn and Se). Implications Although biofortification with 1.5 kg Zn/ha has achieved the concentration in maize biomass that can meet the nutritional needs of dairy cows, further research is needed to examine the adjuvant doses and forms of Zn to obtain high yields and Zn concentration in forage crops.