Intercropping Wheat and Beans: Effects on Agronomic Performance and Land Productivity

Declining land productivity associated with soil degradation is a significant issue for intensive wheat production. An intercropping system combining wheat and grain legumes may provide a farmwide production system that fulfills both economic and environmental concerns. We grew spring wheat ( Triticum aestivum L. ‘Scarlet’) as a monoculture and intercropped with either a common bean cultivar ( Phaseolus vulgaris L. ‘Red Kidney’ or ‘Black Turtle’) or a fava bean cultivar ( Vicia faba L. ‘Bell’) without fertilizer in rows of wheat/bean 1:1 and 2:1 as well as broadcast arrangements during 2011 and 2012 to assess the impact of different genera ( Vicia and Phaseolus ) and cultivars (Red kidney or Black Turtle) on the wheat performance, land productivity, N and C accumulation in aboveground biomass, and soil mineral N balance. As baseline, the monoculture wheat plots yielded 3.2 t ha −1 . However, wheat–fava bean plots displayed higher land equivalent ratio (LER) and total land outputs (TLO) with increased land productivity of 50% in the 1:1 and 32% in the 2:1 arrangements. Intercropped plots in row arrangements also improved wheat biomass nitrogen and grain protein content compared with monoculture plots. Wheat–fava bean in the 1:1 arrangement accumulated the highest N (34 kg ha −1 , i.e., 176% higher) and organic C (2138 kg ha −1 , i.e., 26% higher) in shoot biomass compared with monocultured wheat. Both NH 4 + and NO 3 − pools were higher in intercrop plots with the highest mineral N balance in wheat‐fava bean in the 1:1 arrangement (+0.2 mg NH 4 + and +1.1 mg NO 3 − kg ‐1 dry soil). This study demonstrates that intercropping wheat with fava bean is an efficient strategy to increase land productivity while also increasing forage and soil quality.