Hybrid poplar plantation establishment in Saskatchewan: first year results

Non-Peer ReviewedThe production of Short-Rotation Woody Crops (SRWC) has been growing steadily throughout North America. In Saskatchewan, interest is focused on developing hybrid poplar (var. ‘Walker’) plantations for an expanding fibre industry, and as a means to diversify farm income and possibly to increase sequestered carbon. Preliminary results from a small 6 year-old plantation suggest that there is good potential for operational-scale hybrid poplar production over a 15 to 20 year rotation period. Larger-scale field trials were established in the spring of 2002 on two sites in the Meadow Lake region, to assess and compare select silvicultural practices that are regarded to enhance the growth of hybrid poplars. After one growing season, both types of rooted stock (cuttings and plugs) showed superior survivability (~92 %) compared to non-rooted cuttings (~40 %), underscoring the reduced risk in planting rooted stock, especially during dry years. Measurements of tree growth (tree height, stem volume, total plant biomass and root production) all indicated a noticeable advantage of rooted versus non-rooted stock. Observational data pointed to the necessity of thorough site preparation, adherence to proper planting techniques, and mechanical or chemical weed control for successful plantation establishment

Redistribution of Extractable Nutrients Following Disc Trenching on Luvisols and Brunisols in Saskatchewan

Disc trenching is an important silvicultural management tool for cre- ating microsites to ensure the survival and growth of newly planted seedlings. Mounded microsites are thought to be a source of nutrients for seedling roots; however, little is known concerning how nutrients are redistributed in the soil after disc trenching. The objective of this study, therefore, was to determine the redistribution of soil horizons and selected soil chemical properties fol- lowing Delta disc trenching. Three sites were selected on both Luvisol and Brunisol soils in northern Saskatchewan. Soil profiles were excavated and samples collected from 15 × 15 cm grids to a 1-m depth. Samples were analyzed for pH and extractable nitrate (NO ), ammonium (NH ), phosphorus (P), potassium (K) and sulfur (S). Disc trenching concentrated extractable N, P and S in the 34 berm microsite compared to the trench microsites. The redistribution of extractable NO , NH and P in the berms compared to the 34 trench microsites was 20 times greater for Luvisol sites compared to the Brunisol sites, while extractable K and S were similar between both microsites for each soil. Seedlings planted on these mounded microsites therefore should have a large pool of nutri- ents for plant growth; however, further work is needed to determine patterns of nutrient uptake by seedlings in relation to mound- ed and trench microsites