Cereal–legume intercropping for climate‐smart livestock production: insights from oat–alfalfa intercropping

BACKGROUND Cereal–legume intercropping can improve forage productivity and quality at the same time as enhancing soil function and reducing environmental impacts, yet integrative evaluations under low‐input conditions are scarce. This study assessed oat ( Avena sativa L.)–alfalfa ( Medicago sativa L.) intercropping for forage yield, nutritive value, soil properties and greenhouse gas emission intensity. A randomized complete block design compared sole oat (80 kg ha –1 ), sole alfalfa (15 kg ha –1 ) and oat–alfalfa seed ratios of 3:1, 1:1 and 1:3 without irrigation or fertilisation. Previous intercropping studies examined agronomic productivity and forage quality separately. The current study addresses the gap with an integrated assessment of forage yield, conservation quality, soil health, greenhouse gas emission intensity, livestock production potential and decision metrics of oat‐alfalfa under low‐input conditions. RESULTS Intercropping increased total forage dry matter yield (by 21%), crude protein and metabolisable energy content, and also reduced neutral detergent fibre, compared to sole oat ( P < 0.05). The 1:1 intercrop had significantly the highest land equivalent ratio (1.56) and system productivity index and showed better silage fermentation and dry matter recovery ( P < 0.05). At final sampling, intercropping increased soil organic carbon, total nitrogen, cation exchange capacity and available phosphorus, with a small reduction in soil pH ( P < 0.05). Predicted global warming potential per unit of potential liveweight gain was lower (37–47%) for intercrops than for monocultures for both hay and silage. Multi‐criteria decision analysis consistently ranked the 1:1 intercrop highest across producer‐centric, balanced and environment‐centric scenarios. CONCLUSION Oat–alfalfa intercropping, particularly at a 1:1 seed ratio, provides a promising climate‐smart forage production strategy by simultaneously enhancing productivity, forage quality and soil fertility at the same time as reducing predicted greenhouse gas emission intensity under low‐input conditions.