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Book Carbon and Nitrogen Allocation Patterns of 2 0 Douglas fir Seedlings Following Nitrogen Fertilization in the Autumn

Download or read book Carbon and Nitrogen Allocation Patterns of 2 0 Douglas fir Seedlings Following Nitrogen Fertilization in the Autumn written by Hank A. Margolis and published by . This book was released on 1985 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Douglas-fir (Pseudotsuga menziesii Mirb. Franco) seedlings at a nursery in western Oregon were fertilized with nitrogen in October. Free amino acid (FAA) and total nitrogen concentrations in needles, stems and fine roots were followed from before fertilization until just prior to budbreak the following spring. Before budbreak in mid-March, the FAA and total nitrogen concentrations in the fertilized seedlings were significantly higher than the unfertilized seedlings. Fertilized seedlings showed significant depletion of non-structural carbohydrates (NSC) relative to the unfertilized seedlings. The reduction in carbohydrate reserves following fertilization probably reflects increased respiration associated with the synthesis and maintenance of higher levels of enzymes. The seedlings were lifted from the nursery bed and planted in a split plot design. The main treatment was the presence or lack of grass competition. Within each main plot, the previously fertilized and unfertilized seedlings were planted. Sucrose was applied to the soil around each seedling to limit the availability of nitrogen to tree roots. On the average, the fertilized seedlings broke bud ten days earlier than the unfertilized seedlings and produced more growth aboveground. The earlier budbreak was responsible for initial differences in growth response. Later harvests showed that fertilized seedlings also exhibited higher relative growth rates. Seedlings growing in the grass plots had predawn water potentials of -1.5 MPa by early August. By September 3, the unfertilized seedlings growing with grass showed significantly more predawn water stress than any of the other three treatments. Although the fertilized seedlings had higher FAA and total nitrogen concentrations than unfertilized seedlings when they were planted, by the end of one growing season the FAA arid total nitrogen concentrations had equalized. However, the fertilized seedlings contained more FAA and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and non-structural carbohydrate chemistry. After one growing season, the fertilized seedlings showed a 3 cm increase in height increment; a 29% increase in the number of stem units on the terminal leader; a 44% increase in aboveground growth; a 25% increase in total seedling leaf area; a 23% increase in relative growth rate; and a 14% increase in production per unit nitrogen.

Book Canadian Journal of Forest Research

Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 1997 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Foliar Nutrient Root Chemistry Growth and Carbon Allocation Patterns of Douglas fir Seedlings Grown Under Different Nitrogen and Potassium Treatments

Download or read book Foliar Nutrient Root Chemistry Growth and Carbon Allocation Patterns of Douglas fir Seedlings Grown Under Different Nitrogen and Potassium Treatments written by Terry Mac Shaw and published by . This book was released on 1997 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Growth and Nutrient Allocation of Douglas fir Seedlings

Download or read book Growth and Nutrient Allocation of Douglas fir Seedlings written by Kim Everett and published by . This book was released on 2005* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Regeneration of Douglas-fir following harvesting has proven difficult on many sites in British Columbia. As a result, alternative nursery practices are being explored to improve seedling growth. Using two experiments I aimed to identify an improved nutritional program for Douglas-fir seedlings. The objective of the first experiment was to identify the optimum nitrogen (N) source ratio for Douglas-fir between two inorganic sources of N, ammonium (NH4+) and nitrate (NO3- ). Seedlings were grown in controlled environments in aeroponic culture with solutions containing 0:100, 20:80, 40:60, 60:40, 80:20 or 100:0 NH4+:NO3- ratios. Growth and nutrient allocation was observed for 45 days. Different NH4+ and NO3-ratios resulted in significant differences in growth and nutrient allocation. Seedlings grown in solutions containing abundant and relatively equal portions of NH4+ and NO3- were characterized by the greatest relative growth rates, greatest biomass and stable internal nitrogen concentrations. Seedlings grown in solutions containing high NH4+ (80:20 and 100:0 NHS+:NO3- ) concentrations were characterized by lower relative growth rates, less biomass, lower internal nutrient concentrations and lower rates of photosynthesis and root respiration compared to seedlings with less NH4+ (20:80, 40:60 and 60:40 NH4+:NO3- ). Seedlings appeared to take up a greater proportion of NH4+ than NO3- from solution. The objective of the second experiment was to examine the implications of two nursery fertilization regimes for growth and nutrient dynamics. Seedlings were grown in a nursery with nutrients added at a constant rate (conventional fertilization) or at an exponentially increasing rate of 2% day-1 (exponential nutrient loading). At the time of planting, half of the conventionally fertilized seedlings were planted with slow release fertilizer packets. Growth and nutrient allocation was observed for two years following planting. In the field experiment, although exponential nutrient loading applied 25% more N in the nursery compared to the conventional regime, no benefits in growth or nutrient allocation were found. Two years after planting, there were no significant differences in height, root collar diameter or total dry mass between seedlings grown under the different nursery fertilizer regimes. In contrast, seedlings planted with additional fertilizer consistently outperformed seedlings grown with exponential nutrient loading, with greater height, root collar diameter and dry mass. Two growing seasons after planting there were no significant differences among treatments in whole-plant N concentrations.

Book Dissertation Abstracts International

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1993-06 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Growth and Nutrient Allocation of Douglas fir Seedlings

Download or read book Growth and Nutrient Allocation of Douglas fir Seedlings written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Regeneration of Douglas-fir following harvesting has proven difficult on many sites in British Columbia. As a result, alternative nursery practices are being explored to improve seedling growth. Using two experiments I aimed to identify an improved nutritional program for Douglas-fir seedlings. The objective of the first experiment was to identify the optimum nitrogen (N) source ratio for Douglas-fir between two inorganic sources of N, ammonium (NH4+) and nitrate (NO3- ). Seedlings were grown in controlled environments in aeroponic culture with solutions containing 0:100, 20:80, 40:60, 60:40, 80:20 or 100:0 NH4+:NO3- ratios. Growth and nutrient allocation was observed for 45 days. Different NH4+ and NO3-ratios resulted in significant differences in growth and nutrient allocation. Seedlings grown in solutions containing abundant and relatively equal portions of NH4+ and NO3- were characterized by the greatest relative growth rates, greatest biomass and stable internal nitrogen concentrations. Seedlings grown in solutions containing high NH4+ (80:20 and 100:0 NHS+:NO3- ) concentrations were characterized by lower relative growth rates, less biomass, lower internal nutrient concentrations and lower rates of photosynthesis and root respiration compared to seedlings with less NH4+ (20:80, 40:60 and 60:40 NH4+:NO3- ). Seedlings appeared to take up a greater proportion of NH4+ than NO3- from solution. The objective of the second experiment was to examine the implications of two nursery fertilization regimes for growth and nutrient dynamics. Seedlings were grown in a nursery with nutrients added at a constant rate (conventional fertilization) or at an exponentially increasing rate of 2% day-1 (exponential nutrient loading). At the time of planting, half of the conventionally fertilized seedlings were planted with slow release fertilizer packets. Growth and nutrient allocation was observed for two years following planting. In the field experiment, although exponential nutrient.

Book American Doctoral Dissertations

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Comprehensive Dissertation Index

Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1973 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Herbaceous Vegetation in Forests of the Western United States

Download or read book Herbaceous Vegetation in Forests of the Western United States written by Donna M. Loucks and published by . This book was released on 1991 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Manual for Exponential Nutrient Loading of Seedlings to Improve Outplanting Performance on Competitive Forest Sites

Download or read book Manual for Exponential Nutrient Loading of Seedlings to Improve Outplanting Performance on Competitive Forest Sites written by V. R. Timmer and published by . This book was released on 1996 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a review of principles and technology of exponential fertilisation and nutrient loading for container stock production, an examination of the growth and nutritional responses of loaded seedlings planted on competitive sites, and information for implementing exponential nutrient loading practices on an operational basis. The loading technique presented improves the competitiveness of containerised seedlings planted on vegetation-rich mixedwood sites by promoting initial growth performance and weed suppression. The approach is based on two new preconditioning practices which promote steady-state luxury consumption of nutrients in seedlings for outplanting.

Book Fall Fertilization Effects on Douglas fir Seedling Quality

Download or read book Fall Fertilization Effects on Douglas fir Seedling Quality written by Todd M. Birchler and published by . This book was released on 1997 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) 1 + 1 seedlings were fertilized with two types of fertilizers (NB4NO3+K2SO4 and (NH. 4)2 SO4+KC1) at four rates (0, 80, 160, 320 kg N and K/ha) split over 3 application dates (September 19, October 13, November 1, 1996). By January 10, total Kjeldahl nitrogen (TKN) concentrations increased 16, 30, and 34% and contents increased 6, 20, and 26% for the 80, 160, and 320 kg N/ha treatments relative to the unfertilized seedlings. Potassium levels remained relatively unchanged as a result of the fertilization treatments. Chloride concentrations increased 57, 77, and 112% and contents increased 45, 71, and 92% for the 80, 160, 320 kg K/ha as KC1 relative to the unfertilized seedlings. There was an immediate pulse in nitrate levels following the first application of NH4NO3+K2 SO4, but this was of short duration. Levels of most other nutrients continued to increase between September 16 and January 10, but these increases were generally unrelated to the fertilizer treatments. Although TKN levels increased, nutrient ratios determined as a proportion of TKN decreased, but generally remained within balance. Needle dry weights also increased at this time, but the increase was not related to the treatments applied. There were no differences in root growth potential (as measured by total new root dry weiglht) among the treatments. Seedlings that received 160 and 320 kg N/ha broke bud three days earlier than the unfertilized seedlings. Seedling cold hardiness LT50 levels on October 23, November 13, and December 9 showed no consistent significant differences among the fertilizer treatments. By December 30 all treatments had attained similar LT50 levels ( -14°C). Adding high levels of fertilizers after budset in the fall did not appear to disrupt the cold hardiness process. Detectable differences in baseline seedling variable chlorophyll fluorescence Fvar/Fmax levels among the treatments occurred on November 13 and December 30. Fertilized seedlings had consistently higher Fvar/Fmax than unfertilized seedlings. Fall fertilization to stimulate late season luxury consumption of nitrogen appears to be beneficial if conducted after seedlings have ceased growth and set bud. If no biologically significant nutrient imbalances occur as a result of fertilization, as was the case in this study (up to 320 kg N/ha), seedlings with elevated levels of nitrogen may outperform seedlings with lower levels of nitrogen.

Book Foliar Mineral Content of Forest and Nursery grown Douglas fir Seedlings

Download or read book Foliar Mineral Content of Forest and Nursery grown Douglas fir Seedlings written by Kenneth William Krueger and published by . This book was released on 1967 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: