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Fine roots are of great importance in the uptake of water and nutrients from, and input of, carbon to the soil. This study determined the proportion of extra fine (0.4 mm contributed a small proportion to the total. For pulses (Cicer arietinum L. chickpea, Pisum sativum L. dry pea, and Lens culinaris Medik. lentil), the proportion of roots in the 0- to 0.2-mm diameter was much smaller than that for wheat (Triticum aestivum L.), whereas the proportions of roots in the thicker (0.4 to 0.6, 0.6 to 0.8, and 0.8 to 2.0 mm) diameters were greater than those for wheat. The relative distribution patterns of extra fine and fine roots in oilseeds, pulses, and wheat may provide a guide for further study of detailed rooting systems for oilseeds and pulses. doi: 10.2135/cropsci2009.03.0156

Abstract: An ecosystem management model was used to project total aboveground and belowground production in hybrid poplar plantations for two sites in Saskatchewan that were previously in agricultural production and [...]

A major impediment to the establishment of outplanted conifer seedlings is competition for available soil N by early successional species. The objective of this field study was to determine the fate of controlled-release fertilizer (CRF) N in soils with outplanted white spruce (Picea glauca [Moench] Voss.) and jack pine (Pinus banksiana Lamb.) seedlings, and the effect of weed control or vegetation management (VM) on fertilizer N accumulation. Nitrogen-15 labeled CRF was placed next to the seedling root plug during planting at four boreal mixed wood sites. After one growing season in the control plots, fertilizer N recovery as a percentage of [sup.15]N added was 4% in seedlings, 3% in competing vegetation, 50% of the fertilizer N remained in the fertilizer bag, presumably remaining available in subsequent seasons. Calamagrostis (Calamagrostis canadensis) was the primary competitor for fertilizer N in both growing seasons, with minor competition from fireweed (Epilobium angustifolium L.), and aspen (Populus tremuloides Michx.). The use of a point source CRF delivery method resulted in high fertilizer use efficiency (FUE), and minimized losses to competing vegetation and leaching.

Accurate sorption measurements are required for predicting contaminant mobility during the leaching of hydrophobic organic chemicals from contaminated sites. The in situ column technique was evaluated for usage in studies of organic contaminant sorption and transport. The results showed that the in situ column could be used to obtain site-specific estimates of equilibrium and nonequilibrium sorption parameters. In addition, a mathematical model for the quantitative evaluation of sorptive solute transport within the in situ column was developed.

Wood ash amendment to forest soils contributes to the sustainability of the growing bioenergy industry, not only through decreased wood ash waste disposal in landfills but also by increasing soil/site productivity and tree growth. However, tree growth studies to date have reported variable responses to wood ash, highlighting the need to identify proper application rates under various soil/site conditions to maximize their benefits. We explored the influence of tree species, wood ash nutrient application rates, time since application, stand development stage, and initial (i.e., before wood ash application) soil pH and N on short‐term tree growth response to wood ash amendment across eight unique study sites spanning five Canadian Provinces. Jack pine (Pinus banksiana Lamb) had the most positive response to wood ash amendment compared to white (Picea glauca Moench), hybrid (Picea engelmannii x glauca Parry), and black spruce (Picea mariana Miller), where increasing nutrient application rates increased height growth response. In comparison, black spruce had the most negative response to wood ash amendment, where increasing nutrient application rates slightly decreased height growth response. Site as a random effect explained additional variation, highlighting the importance of other unidentified site characteristics. By examining trends in short‐term growth response across multiple studies with variable site characteristics, we found growth response differed by tree species and nutrient application rates, and that jack pine is a promising candidate for wood ash amendment. These results contribute to our knowledge of optimal wood ash amendment practices and environmentally sustainable bioenergy production. [ABSTRACT FROM AUTHOR]