Inoculant formulation and fertilizer nitrogen effects on field pea: Crop yield and seed quality

Appropriate rhizobial inoculation and fertility management can increase field pea (Pisum sativa) seed yield and improve yield stability in western Canada. The objective of this study was to determine the effect of inoculation method and N fertilizer application on pea seed yield and quality. The effects of soil inoculant (granular) and seed-applied inoculant (peat powder or liquid) used with and without urea-N application on field pea were investigated in the Peace River region of Western Canada. At low applied N rates, field pea biomass was significantly higher for soil-applied inoculant as compared to seed-applied inoculant. Soil-applied inoculant resulted in 15, 18, 9 and 0% higher pea biomass yield at the flatpod stage than seed-applied inoculant at 0, 20, 40 and 80 kg N ha(-1) respectively. Averaged over all N rates, soil-applied inoculant resulted in 17, 50, and 56% higher pea seed yield than peat inoculant, liquid inoculant, or the uninoculated check, respectively. Soil-applied inoculant increased the proportion of the biological yield converted to seed compared to seed-applied inoculant. Seed protein concentration increased by 12 and 15% when inoculant was soil-applied compared with seed-applied or uninoculated pea, respectively. Without N fertilizer, soil-applied inoculant increased field pea biomass, seed yield and protein concentration and contributed to increasing yield stability compared with seed-applied inoculant.