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. Rhizobial inoculant formulations and soil pH influence field pea nodulation and nitrogen fixation. Can. J. Soil Sci. 80: 395-400. Crop production systems that include field pea (Pisum sativum L.) in rotation are important for sustainable agriculture on acid soils in northwestern Canada. Greenhouse experiments were conducted to compare the ability of liquid inoculant applied to the seed, powdered peat inoculant applied to the seed, and granular inoculant applied in a band with the seed to establish effective nodulation on field pea grown at soil pH(H 2 O) 4.4, 5.4 and 6.6. Plants were grown to the flat pod stage, and then total plant biomass dry weight, dry weight of nodules, number of nodules, plant nitrogen content, and proportion of plant nitrogen derived from the atmosphere (%Ndfa) were measured. Granular and powdered peat inoculants produced greater nodule numbers and weight, plant nitrogen content, %Ndfa and total biomass than liquid inoculant in at least two of the three experiments. Only granular inoculant was effective in establishing nodules at soil pH 4.4, but granular and powdered peat inoculants were effective at pH 5.4, and all three formulations were effective at pH 6.6. The results showed that granular inoculant has potential for effective nodulation of field pea grown on acid soil. . Les plantes étaient cultivées jusqu'au stade de la gousse plate, après quoi on mesurait le poids sec total de la biomasse, le poids sec des nodosités, la teneur en N de la plante et la proportion de N provenant de l'atmosphère (%Nat). Les inoculants sur tourbe, granulés ou pulvérulents donnaient des nodosités plus abondantes et plus lourdes ainsi qu'une teneur en N de la plante, un %Npat et une biomasse totales plus élevés que la présentation liquide. Dans au moins deux des trois expériences, seul l'inoculant granulé réus-sissait à produire des nodosités viables au pH 4,4, mais au pH 5,4 les deux inoculants sur tourbe étaient efficaces et au pH 6,6 les trois présentations l'étaient toutes. Il découle de ces observations que l'emploi d'un inoculant granulé peut garantir une nodulation viable chez le pois cultivé en sols acides.

No abstract

. 1993. The use of annual legume green-manure crops as a substitute for summerfallow in the Peace River region.Can. J. Soil . Field studies were conducted on a Landry clay-loam soil (Black Solod) to evaluate the effects of green manuring Tangier flatpea (Lathyrus tingitanus 'Tinga'), lentil (I'ens culinaris'Indianhead') and alfalfa (Medicago sativa 'Moapa') on subsequent barley (Hordeum vulgare 'Galt') crops. Each trial consisted of separate legume phases planted in 1984, 1985 and 1986 and barley phases in each of the subsequent years. The flatpea and lentil were incorporated (green manured) in late July or in late August to early September. The alfalfa was incorporated in late August to early September. The 3-yr mean dry matter (DM) yields of lentil and Tangier flatpea varied from 1047 to 2308 kg ha-r, with considerable variability from year to year. Alfalfa, used as an annual legume, produced 8l2kg DM ha-r.. Dinitrogen early incorporation (full bloom) and (8) (1985, 1986 and 1987), barley was grown on all plots (barley phase) which were fertilized the sarne as the previorrs year, i.e., treatment 2 received 100 kg N ha-' and all treatments received 20 kg P ha-'.Soil samples were taken to a depth of 120 cm at increments of0-15, l5-30, 30-60, 60-90 For the barley harvested at maturity in both the legume and barley phases, yield samples from two rows, 5 m in length were taken. Grain and straw yields were obtained and sub-samples kept for total-N analysis.

Antisera were prepared against five Rhizobium meliloti strains including three strains adapted to Canadian soil and climate conditions and recently released for use in the production of commercial alfalfa (Medicago spp.) inoculants. The antisera were highly cross-reactive, but specificity was obtained by repeated massive adsorptions of the antisera with cells of the cross-reacting strains. The adsorbed antisera were used in microagglutination tests and the enzyme-linked immunosorbent assay (ELISA) to demonstrate the presence of the Canadian strains in their respective commercial peat-base inoculants at 108–109 viable cells/g. A plant infection technique which was also used to evaluate inoculant quality was specific only at the Rhizobium species level and required up to 4 weeks for completion. Serological techniques made it possible to identify and quantitate inoculant strains of R. meliloti while reducing the time required for testing. The agglutination analysis of inoculants was simple, but required regrowth of each colony isolate to generate sufficient cell numbers. The ELISA technique was used directly with colonies picked from plate counts, and the results were available within 5 days, including the time for colony growth on the plate media.