ABSTRACT
Intercropping, a mix of non-legume and legume crops, can improve crop yield and/or economic returns and reduce input costs. Field experiments (barley-pea intercrop) were conducted in 2008, 2010 and 2011 on an Oskondoga silt loam soil at Thunder Bay, Ontario, Canada, to determine the effect of intercropping barley (non-legume) and pea (legume) on grain yield, land equivalency ratio (LER), grain quality (protein concentration-PC), N uptake and economic returns. Barley and pea were grown as mono crops and in combinations as intercrops (both in the same row/and alternate rows). Nitrogen fertilizer was applied at 0, 40 and 80 kg·N·ha-1 to mono crop barley and at 0, 20 and 40 kg·N·ha-1 to barley-pea intercrop combinations. On an average of three years, application of 80 kg·N·ha-1 increased grain yield of barley by 846 kg·ha-1 as a sole crop and by 420 - 488 kg·ha-1 in the two intercropping combinations. Compared to barley and pea as sole crops, grain yield with barley-pea intercropping was greater by 266 kg·ha-1 with alternate row combination and by 223 kg·ha-1when both crops were grown in the same row. The LER values suggested 7% - 17% less land requirement for barley-pea intercropping than sole crops. Net returns from barley-pea intercropping without applied N greatly improved ($854 - $939 ha-1) compared to barley sole crop with 80 kg·N·ha-1($628 ha-1), although the net returns were highest for pea grown as a sole crop without applied N ($1141 ha-1). For barley as a sole crop, PC in grain increased with applied N. Compared to barley as sole crop with zero-N, PC in barley grain increased when barley was intercropped with pea. In barley-pea intercrop treatments, application of N fertilizer had no significant effect on PC in barley grain, although PC in pea grain was much higher than PC in barley grain. The response trends of total N uptake in grain were similar to grain yield. The findings suggest that pea or barley-pea intercropping could be an option for organic farming systems.