Intercropping is an eco-friendly agricultural practice for achieving higher quantity and quality of forage crops. The present study was aimed to evaluate the forage quality, quantity and ecological indices (monetary and competition) of maize in intercropping with different legumes at two different growing years (2017–2018) in the north west of Iran. The treatments were monoculture of two maize hybrids (KSC301 and KSC704), grasspea (Lathyrus sativus L.), berseem clover (Trifolium alexandrinum L.), bitter vetch (Vicia ervilia L.), hairy vetch (Vicia villosa L.) and additive intercropping of two maize hybrids with the above mentioned legumes. The highest and lowest total forage yield and crude protein yield (CPY) was achieved in intercropping of KSC301 with hairy vetch and maize monocultures. Also, the highest value of total digestible nutrients (TDN), dry matter digestibility (DMD), dry matter intake (DMI) and net energy for lactation (NEl) was observed in intercropping of KSC301 with grasspea. In addition, acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents in maize monocultures increased by 19% and 29% compared with intercropping patterns. Averagely, the highest RVT was calculated in the intercropping of KSC301 with grasspea and KSC301 with hairy vetch. The maximum LER was achieved in intercropping of KSC301þ hairy vetch and KSC704þ hairy vetch. Generally, based on the forage quantity, quality and monetary indices, intercropping of KSC301 with grasspea and KSC301 with hairy vetch was superior to maize monocultures and can be suggested, as an eco-friendly and cleaner production method, to farmers instead of monoculture systems
