Nitrogen competition using 15N between early successional plants and planted white spruce seedlings

1999 ◽  
Vol 29 (8) ◽  
pp. 1282-1289 ◽  
Author(s):  
Thomas E Staples ◽  
Ken CJ Van Rees ◽  
Chris van Kessel

The ability of noncrop plants to compete with white spruce (Picea glauca (Moench) Voss) seedlings for applied fertilizer N is not well understood. Therefore, the objective of this study was to examine the efficacy of fertilizer N uptake using 15N by planted white spruce seedlings and understory vegetation. Double 15N-labeled NH4NO3 was broadcast in 1-m2plots for control, disc-trenched, and disc-trenched + manual brushing treatments. The fate of applied 15N in white spruce and noncrop plants was determined at the end of the first two growing seasons. The major competitors for fertilizer 15N were Populus tremuloides Michx. and grasses during the first growing season, and Populus tremuloides, Epilobium angustifolium L., and Achillea millefolium L. during the second growing season. Disc-trenching plus manual brushing significantly increased the fertilizer use efficiency of white spruce seedlings by limiting competition; however, <1% of the applied fertilizer 15N was utilized by the spruce seedlings after two growing seasons. The ability of competing vegetation to absorb broadcast fertilizer N suggests that alternative fertilizer types and placements be investigated to increase N uptake by white spruce seedlings planted in the boreal mixedwood forest.

2012 ◽  
Vol 92 (3) ◽  
pp. 563-575 ◽  
Author(s):  
R. D. Hangs ◽  
J. J. Schoenau ◽  
K. C. J. Van Rees ◽  
J. D. Knight

Hangs, R. D., Schoenau, J. J., Van Rees, K. C. J. and Knight, J. D. 2012. The effect of irrigation on nitrogen uptake and use efficiency of two willow ( Salix spp.) biomass energy varieties. Can. J. Plant Sci. 92: 563–575. Nitrogen (N) fertilizers historically have been applied to support increased productivity of purpose-grown willow (Salix spp.) biomass energy plantations. However, a frequently observed lack of willow growth response to added fertilizer N is often attributed to poor fertilizer use efficiency. The objective of this study was to determine the effect of irrigation on the recovery of broadcast15N-labelled fertilizer, applied during the final year of a 3-yr rotation, by two willow varieties. A split-split-plot experiment was established on a fertile heavy clay soil in Saskatoon, SK, Canada, which consisted of two willow varieties (Charlie and SV1), three irrigation treatments (no irrigation, 75%, and 100% field capacity), and two fertilization treatments (1× and 2× the recommended fertilizer rate of 100:30:80:20 N:P:K:S; kg ha−1). Irrigation increased fertilizer N uptake by Charlie, but had no effect on the amount taken up by SV1, which was attributed to greater N use efficiency of SV1 compared with Charlie when irrigated. Eighty-two percent of the applied fertilizer N was accounted for in the following sinks: 43% in the soil (0–60 cm), 31% in the willow tissues (i.e., stems, leaves, stump, and roots), 7% in the LFH layer, and <1% in the non-crop vegetation; the balance (approximately 18%) was presumed lost primarily through denitrification from the poorly drained soil, but possibly some may have leached below the root zone as well. Although the willow varieties accessed only a portion of the applied fertilizer N during the year of application, the majority of the residual fertilizer N was conserved within the production system and, therefore, remained available for willow uptake in subsequent years.


1995 ◽  
Vol 71 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. F. Sutton ◽  
T. P. Weldon

Five-year results of a study to evaluate the relative effectiveness of nine silvicultural treatments for establishing plantations of white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixed-wood are presented. The experimental design provided three levels of mechanical site preparation (none, disk trenching, and toothed-blading) in all combinations with three kinds of chemical weed control (none, Velpar L© at the time of planting, and Vision© during the second growing season). A randomized block experiment using 0.8-ha plots and two replications was established in Oates Twp. in 1985 and repeated in adjacent Oswald Twp. in 1986. Bareroot white spruce was planted throughout. Four 25-tree sub-plots, located systematically from a random start, were established in each plot. White spruce performance was monitored for five years. Fifth-year survival rates averaged 34% and 84% without and with mechanical site preparation, respectively. Mean total heights after five growing seasons differed significantly (P < 0.01) by category of mechanical site preparation: teeth > trencher > none. Other criteria of performance showed the same pattern. Because of operational exigencies, the herbicide treatments were not applied as scheduled, which might account for the apparent ineffectiveness of those treatments in the particular circumstances of this study. Key words: Site preparation, disk trencher, Young's teeth, herbicides


HortScience ◽  
2009 ◽  
Vol 44 (6) ◽  
pp. 1712-1718 ◽  
Author(s):  
Laura L. Van Eerd ◽  
Kelsey A. O'Reilly

The increase in fertilizer costs as well as environmental concerns has stimulated growers to re-evaluate their fertilizer applications to optimize nitrogen use efficiency (NUE) while maintaining crop yields and minimizing N losses. With these objectives, field trials were conducted at seven sites with five N rates (0 to 220 kg N/ha) of ammonium-nitrate applied preplant broadcast and incorporated as well as a split application treatment of 65 + 45 kg N/ha. In three contrasting years (i.e., cool/wet versus warm/dry versus average), N treatment had no observable effect on grade size distribution or brine quality. Based on the zero N control treatment, the limited yield response to fertilizer N was the result of sufficient plant-available N over the growing season. In the N budget, there was no difference between N treatments in crop N removal, but there was a positive linear relationship between N applied and the quantity of N in crop residue as well as in the soil after harvest. As expected, apparent fertilizer N recovery and N uptake efficiency were lower at 220 versus 110 kg N/ha applied preplant or split. The preplant and split applications of 110 kg N/ha were not different in yield, overall N budget, or NUE. Considering the short growing season, planting into warm soils, and the generally productive, nonresponsive soils in the region, growers should consider reducing or eliminating fertilizer N applications in machine-harvested cucumber.


2003 ◽  
Vol 33 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Ryan D Hangs ◽  
J Diane Knight ◽  
Ken CJ Van Rees

Little is known about the N uptake abilities of competitor species and planted seedlings in the boreal forest. The objective of this study was to determine the Michaelis–Menten kinetic parameters of NH4+ and NO3– for white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb.) seedlings, and three competitive common boreal forest early successional species: aspen (Populus tremuloides Michx.), fireweed (Epilobium angustifolium L.), and cala magrostis (Calamagrostis canadensis (Michx.) Beauv.). Uptake kinetics were measured in hydroponic cultures and expressed as maximum uptake (Imax) and ion affinity (Km). The ranking of Imax values (pmol·cm-2·s–1) for NH4+ uptake was calamagrostis (84.6), fireweed (58.1), white spruce (20.7), aspen (12.5), and jack pine (10.9), and for NO3– uptake was calamagrostis (17.7), fireweed (12.5), aspen (5.8), white spruce (4.5), and jack pine (2.1). The ranking of Km values (µM) for NH4+ uptake was calamagrostis (125.9), fireweed (163.8), aspen (205.7), white spruce (217.1), and jack pine (270.5), and for NO3– uptake was calamagrostis (229.9), fireweed (274.6), aspen (336.5), white spruce (344.5), and jack pine (350.5). Calamagrostis exhibited the greatest uptake rates and affinity for NH4+ and NO3–, suggesting that silviculture practices that specifically reduce establishment of this grass should benefit the growth of planted seedlings.


2003 ◽  
Vol 79 (1) ◽  
pp. 127-131
Author(s):  
R F Sutton ◽  
T P Weldon

An experiment to investigate techniques for establishing white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixedwood was begun in 1985 in Oates Twp. Eight 25-tree plots were established in each of nine treatments: three mechanical site preparation treatments (none, disk- trenching, and toothed-blading) in combination with three kinds of chemical weed control (none, Velpar L® at the time of planting, and Vision® during the second growing season). The experiment was repeated the following year in the adjacent township of Oswald. The mechanical treatments were applied as planned, but the herbicide treatments deviated somewhat from the plan. Fifth-year results were reported in this journal in 1995. In the eighth growing season, a ground-spray release treatment with Vision® was applied to four randomly selected 25-tree plots in each original treatment. Performance of white spruce after 13 growing seasons was significantly influenced by site preparation: survival averaged 65 and 79% without release in the blading and trenching treatments, respectively, and 22% in the untreated control; with release, survival averaged 74 and 80% in the blading and trenching treatments, respectively, and 24% in the untreated control. Growth was greatest in the bladed treatment, poorest by far in the untreated control. The ineffectiveness of herbicides in these experiments is surprising in view of successes elsewhere. The modest response to release was significant for 13th -year increment. Key words: site preparation, toothed blading, trenching, release


1965 ◽  
Vol 41 (4) ◽  
pp. 454-465 ◽  
Author(s):  
R. E. Mullin

Several kinds of seedbed mulch were used in an experiment to study frost heaving of white spruce (Picea glauca (Moench) Voss) in a nursery. Treatments consisted of silica gravel (of three sizes), hardwood sawdust, vermiculite, shredded sphagnum, mixed silica and sphagnum, and rye straw (the regular nursery mulch). These were applied to beds sown in the fall of 1958, 1959 and I960. Shading of beds during the winter between the first and second growing seasons was also examined.During the first growing season, several counts were made of the number of trees and weeds. At the beginning of the second growing season a count was made of the trees heaved and the residual stand. At the beginning of the third growing season, samples were taken for laboratory measurements of top length, root length, stem diameter, oven-dry weight and top-root ratio.The sawdust mulch was superior in most respects. It permitted the highest germination and survival, better prevention of heaving than rye straw, and better weed control than rye straw. Although the sawdust mulch treatment produced small and poorly balanced trees this was believed due chiefly to high bed density, and compared favourably with the rye straw. The use of hardwood sawdust as a mulch offered considerable advantage over the presently used rye-straw.Heaving was found to be a minor cause of mortality over the three year period examined. Shading of the beds offered no advantage in reducing this loss.


2011 ◽  
Vol 26 (2) ◽  
pp. 82-90 ◽  
Author(s):  
Richard D. Kabzems ◽  
George Harper ◽  
Peter Fielder

Abstract Managing boreal mixed stands of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca [Moench] Voss) is more likely to sustain a diversity of values and has the potential to increase productivity at both the site and landscape levels compared with pure broadleaf or conifer management. In this study, we examine growth of white spruce and aspen after 11 growing seasons over a range of aspen densities created by spot and broadcast treatment of broadleaves using manual and chemical means, aspen spacing, and an untreated control. Results indicate that survival and growth of both spruce and aspen were similar across the range of treatments. Spruce groundline diameter was greater, and height to groundline diameter ratio was lower, for the treatments in which aspen was chemically controlled or uniformly spaced compared with the control. Light measurements at the individual tree level suggested that increased light availability improved white spruce diameter growth. Spruce height growth did not vary by treatment. The status of these experimental mixedwoods was compared with current conifer and mixedwood regeneration evaluations, as well as the preharvest composition of the original stand. After 11 growing seasons, growth of aspen and white spruce indicated that opportunities exist to further modify aspen density to enhance treatment longevity and effectiveness to produce a greater range of boreal mixedwood stand types.


2015 ◽  
Vol 45 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Ya-Lin Hu ◽  
Yue Hu ◽  
De-Hui Zeng ◽  
Xiao Tan ◽  
Scott X. Chang

Exponential fertilization has been shown to be a useful technique for improving seedling quality during nursery production. In this study, we evaluated (i) the impact of exponential vs. conventional fertilization on trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings during nursery production and (ii) the growth performance and nitrogen (N) utilization of those seedlings in response to foxtail barley (Hordeum jubatum L.) competition after the transplantation of seedlings in a greenhouse experiment. Exponential fertilization with an application rate higher than the conventional fertilization increased the internal N reserve in trembling aspen and white spruce seedlings during nursery production and also increased new leaf, new stem, and old stem biomass and N retranslocation rates in trembling aspen seedlings but not in white spruce seedlings after transplantation. Foxtail barley competition decreased N concentrations in seedlings and soil N uptake by the seedlings; however, increased N retranslocation rates with foxtail barley competition were observed in white spruce seedlings but not in trembling aspen seedlings. Our results suggest that the growth performance of seedlings was improved by N loading, whereas the impact of vegetation management was species specific.


2000 ◽  
Vol 15 (4) ◽  
pp. 177-182 ◽  
Author(s):  
James D. Stewart ◽  
Simon M. Landhäusser ◽  
Kenneth J. Stadt ◽  
Victor J. Lieffers

Abstract This study investigated the establishment and survival of naturally and artificially seeded white spruce (Picea glauca), as well as three sizes of planted white spruce stock, on different types of scarification beneath mature aspen (Populus tremuloides) in northern Alberta. White spruce seed rain, natural and hand-seeded regeneration establishment and survival, and understory vegetation response were monitored for 4 yr on scarified strips (light blading, heavy blading, and ridged) and on undisturbed controls. Despite a heavy seed rain in 1993, seedling establishment on control plots was almost nil. On scarified plots, the number of seeds required to produce a live seedling after 3 growing seasons ranged from 15 to 37 and up to 68 in one site. Most mortality occurred during the summer. Germination rate on the hand-seeded plots ranged from 19 to 28% on the scarified strips. There was no significant difference in survival from seed (15%) after three growing seasons among the three scarification treatments. Survival of planted stock was 98% on scarified strips and 96% on control strips. Diameter growth was least on control plots but was not significantly different among the scarified treatments. In contrast, height increment was greatest on the light blading treatment and differed little among the other two treatments and control. These results suggest that spruce regeneration in aspen forests can be promoted by scarification or underplanting. West. J. Appl. For. 15(4):177–182.


2016 ◽  
Vol 46 (8) ◽  
pp. 1051-1058 ◽  
Author(s):  
Emma Despland ◽  
Thomas Bourdier ◽  
Emilie Dion ◽  
Eric Bauce

We examine the extent to which foliar monoterpenes are trapped in the epicuticular waxes as part of an investigation into their role in natural defense against folivores. We monitored concentrations in white spruce (Picea glauca (Moench) Voss) previous-year foliage and expanding foliage and their epicuticular waxes over the 2010 (14 trees) and 2011 (25 trees) growing seasons. In 2010, concentrations were low in the spring and increased over the summer; in 2011, they stayed low. The monoterpene profile of individual trees was similar between years and showed a consistent pattern over the growing season; in expanding foliage, δ-3-carene was only present in spring, whereas bornyl acetate increased over the growing season. Individual wax monoterpene profiles correlated with those of foliage, but the total concentration showed a different phenological pattern. Total content remained constant throughout the growing season on previous-year foliage but decreased on expanding foliage. Electron microscopy suggests this is due to changes in stomatal wax plugs and their role in blocking evaporation from the stomata. These findings suggest that insects contacting the leaf surface will receive accurate information from the wax chemical composition about the monoterpene mix but not about overall monoterpene levels.


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