This paper presents the results of a study conducted in 2016–2018 in the temperate conditions to evaluate the content and uptake of P, K, Ca and Mg in mixtures of narrowleaf lupin with spring triticale grown for green fodder. Two factors were analysed in the experiment: A – the proportion of components in the mixture: narrowleaf lupine 100%, narrowleaf lupine + spring triticale 75 + 25%, 50 + 50%, 25 + 75%, and spring triticale 100%; B – the harvest stage the flowering stage of narrowleaf lupine, the stage of flat green pod of narrowleaf lupine. Increasing the proportion of spring triticale in the sown mixtures in relation to narrowleaf lupine resulted in a decrease in the content of the analysed macroelements by 8.9%–28.7% on a g/kg DM basis. The greatest uptake on a kg/ha basis of macroelements was found in the mixture with an equal share of both components. Harvesting mixtures at a later stage of development increased the uptake of P, K, Ca and Mg by 98.7%–111.8% because of greater DM yield, but reduced the content of these macroelements by 12.6%–20.8% in the more mature fodder. Mixtures of narrowleaf lupine with spring triticale can provide valuable mineral nutrients for livestock.