Cluster of nodules on Alnus; N-fixing by Actinomycetes. Spodosol, HF, BSY.

Nodules on black locust (robinia pseudoacacia) with rhizobium bacteria nitrogen-fixing; see slides #42 and 43. Alfisol, HF, BSY.

Cross-section of black locust nodule (x4) to show general structure and the red colour due to presence of 'leghemoglobin' which shows there is active nitrogen-fixation. Alfisol, HF, BSY.

Cross-section of black locust nodule (x360) to show rhizobium cells the bacteria which due the nitrogen-fixation. Alfisol, HF, BSY.

Profile under 300+ year Douglas fir and red cedar; Ah 25cm with worms; silt loam with gleying at 60cm; Pack Forest near Puyallup. Mollisol, P, C, D.

Brown forest with Ah under 36 year red cedar at Haney (UBC Forest); B horizon has concretions called 'shot'. Mollisol, P, C, F, D.

Thin regosol under grass and open stands of ponderosa pine; near Kelowna. Entisol, P, C, F, S.

General view of solonetzic brown soil near Drumheller; n.b. the light colour of the Csk and the columnar B. Aridisol, P, C, D.

Closeup of the Ah Horizon in the Solonetz to Show the Granular Structure; Same Profile as Slide #47. Ardisol, Ah, S, D.

Lodgepole Pine Forest on Cobbly Pumice Soil (Regosol-Brown Podzolic) near Chemult Or. Inceptisol, P, S, F, D.