Field Pea, Faba Bean and Lupin Contributions to a Subsequent Wheat Crop.
Sheri Strydhorst1, Jane R. King1, Ken J. Lopetinsky2, George Clayton3, and Neil Harker4. (1) Univ of Alberta, Box 270, Neerlandia, AB T0G 1R0, Canada, (2) Alberta Agriculture, Food and Rural Development, Main Floor, Provincial Building 6203 - 49 St, Barrhead, AB T7N 1A4, Canada, (3) Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 - 1st Ave South, PO Box 3000, Lethbridge, AB T1J 4B1, Canada, (4) Agriculture and Agri-Food Canada, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada
Pulse species fix atmospheric nitrogen (N) and reduce N fertilizer input costs, but they also contribute N and non-N benefits to the subsequent year’s crop. Research is being conducted to determine if different pulse species, pulse planting densities and cropping systems differ in their positive contributions to a subsequent wheat crop. Field experiments were conducted at three sites in north-central Alberta, Canada. In 2004, faba bean (Vicia faba), lupin (Lupinus angustifolius) and pea (Pisum sativum) were grown at four planting densities (0.5x, 1.0x, 1.5x, 2.0x the recommended monoculture planting density (PD)) as monocultures, and intercropped with barley (at 0.25x normal PD). At harvest, above ground pulse crop residues were removed to simulate straw baling. In 2005, the pulse stubble was seeded to hard red spring wheat (Triticum aestivum) and fertilized with P, K and S to augment the wheat crop nutrient requirements. No nitrogen fertilizer was applied. Wheat plant heights and straw dry matter production differed depending on the previous year’s stubble type. Seed size, as measured by 1000 kwt, was significantly affected by the previous year’s cropping system, pulse species and pulse seeding rate (P<0.001). Preliminary results indicate significantly higher wheat yields (4.9 t ha-1) were produced on pea monoculture stubble compared with wheat yields from faba bean and lupin monoculture stubble (4.3 t ha-1) (P<0.001). Significantly lower wheat yields were achieved on lupin intercrop stubble (3.8 t ha-1) compared to faba bean or pea intercrop stubble (4.4 t ha-1) (P<0.001). Higher pulse planting densities in the previous year tended to increase wheat yields. Based on first year results, field pea monoculture stubble produced the highest subsequent wheat seed yield, 1000 kwt and straw yield.