Yield Effect of Pulses on Subsequent Cereal Crops in the Northern Prairies

A study comparing the crop sequences pulse-barley-wheat and barley-barley-wheat, was conducted from 1982 to 1987 on Black and Gray-wooded soils in northeastern Saskatchewan. Faba bean (Vicia faba L.), field pea (Pisum sativum L.), and lentil (Lens culinaris Medic.) had similar effects, increasing subsequent cereal yield, on average, by 21% in the first and 12% in the second year. Incorporation of pulse residue was not necessary in order to attain high yields. The yield response of barley (Hordeum vulgare L.) to N fertilizer was slightly greater on barley than on pulse residue, but N fertilizer alone was unable to bring the yield on barley residue up to the yield on pulse residue. However, there were great differences in the effect of year, soil type, preceding crop, residue incorporation, and fertilizer response, and there were many significant interactions of these treatments. These treatment effects could not be consistently accounted for by differences in N cycling, soil moisture, or disease.