Rainfed pulse–pulse and pulse–oilseed intercrops: yield, nutrient uptake, and risk buffering

Context Intercropping can improve resource-use efficiency, yield stability, and profitability, but pulse–pulse intercrops remain poorly studied in mechanised dryland systems. Aims To determine whether functional complementarity among pulse–pulse and pulse–oilseed crops improves yield, nutrient uptake, phenological risk buffering, and profitability under rainfed conditions. Methods Field experiments conducted in southern Australia from 2019 to 2024 compared monocultures with pulse–pulse (lentil–faba bean; faba bean–field pea) and oilseed–pulse (canola–field pea, canola–faba bean, linseed–chickpea) intercrops across locations and sowing dates. Key results Functionally divergent intercrops such as canola–field pea recorded land equivalent ratios (LER) of >1 and nutrient uptake LERs for nitrogen, phosphorus, and sulfur that exceeded unity. By contrast, chickpea–linseed and lentil–faba bean intercrops underperformed with LERs of <1. Faba bean–field pea mixtures yielded similarly to or better than sole crops across environments, with mean LERs near or above 1. Field pea performed better in low-rainfall environments, whereas faba bean performed better in favourable conditions. These complementary responses reflected phenological divergence, with faba bean flowering earlier and field pea maturing sooner. Grain protein concentration remained stable across faba bean–field pea mixtures and was environment-driven. Gross margins were competitive and stable, with some mixtures outperforming monocultures in both yield and profitability. Conclusions Pulse–pulse intercropping offers a low-barrier diversification strategy for mechanised dryland systems. Functional complementarity underpinned agronomic and economic benefits, with nutrient uptake advantages greatest in functionally distinct oilseed–pulse intercrops. Implications Intercropping can improve productivity, profitability, and resilience in low-input dryland systems, although benefits depend strongly on species selection and functional contrast.