Triticale–lupin intercropping offers a viable option for low‐input systems in Mediterranean environments

Abstract Triticale and lupin are promising candidates for sustainable intercropping in low‐input, mixed crop–livestock farming systems in the Mediterranean basin, where they can be grown as rain‐fed crops during the autumn‐winter period. A 2‐year field trial was conducted in Sardinia, Italy, to compare triticale–lupin row intercropping (IC) with triticale sole cropping (TSC) and lupin sole cropping under four fertilization treatments: nitrogen only (‘N,’ 100 kg ha −1 ), phosphorus only (‘P,’ 39 kg ha −1 ), nitrogen and phosphorus combined (‘NP,’ 100 kg ha −1 of N + 39 kg ha −1 of P), and an unfertilized control (‘0’). Measurements included radiation interception, dry matter (DM) production, N percentage, and N uptake per unit area (N yield) at various samplings, along with grain and N yield at maturity. While both species shared a common growing cycle duration, lupin's slower canopy development and shorter height limited its radiation interception and DM production in the intercrop. However, complementarity in DM and N yield was observed across all four sampling dates under the 0 and P treatments, with land equivalent ratio values peaking at 1.71 under the 0 treatment and 1.63 under the P treatment for DM, and around 2 for N yield. The higher DM at maturity translated into greater grain yields for IC compared to TSC under the 0 (3.9 vs. 3.2 t ha −1 ) and P treatments (4.3 vs. 3.6 t ha −1 ). IC also outperformed TSC in terms of DM N percentage, particularly at triticale anthesis, with notable differences in the 0 (N% = 1.09 for IC, 0.79 for TSC) and P treatments (N% = 1.17 for IC, 0.83 for TSC). This higher DM N percentage of IC was likely associated with the higher radiation‐use efficiency of IC compared to TSC under the 0 fertilization treatment. Furthermore, intercropping triticale with lupin demonstrated potential to replace N fertilization without compromising DM or N content in DM and in straw. The observed complementarity in the absence of fertiliser suggests that this intercrop could be especially suitable for low‐input systems. The experimental approach helped link the N‐related benefits of cereal–legume intercrops to radiation acquisition and radiation‐use efficiency, while highlighting the critical role of canopy developmental rates, and hence of cultivar choice, when height differences are substantial.