scholarly journals Fall-Applied Nitrogen Improves Performance of 1-0 Slash Pine Nursery Seedlings after Outplanting

1998 ◽  
Vol 22 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Kris M. Irwin ◽  
Mary L. Duryea ◽  
Earl L. Stone

Abstract This study examined the effects of supplemental nitrogen (N) applied to slash pine (Pinus elliottii var. elliottii [Engelm.]) seedlings in a north central Florida nursery. Treatments were applied during a 4 wk period during November and December, 1989, as follows: control (no fall fertilization—current nursery practice); low N (one application of NH4NO3 at 57 kg N/ha); and high N (three applications at the same rate). At time of lifting and outplanting, there were no significant morphological differences among the treatments, but foliar N concentration increased significantly in accord with treatment. Field performance was evaluated at five site-prepared locations. First-year survival of high N and low N treatments were 15 and 12% greater, respectively, than unfertilized seedlings. First-year heights of the high and low N treatments were 15 and 7% greater, respectively, than the control. South. J. Appl. For. 22(2):111-116.

1990 ◽  
Vol 20 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Paul E. Heilman

Eleven months after the May 1980 eruption of Mount Saint Helens in southeastern Washington, United States, three Populus clones were planted in an experiment on the Toutle River mudflow deposit. The trees grew at an abnormally slow rate and by 3 years were overtopped by a dense stand (14 600 ± 3600 trees/ha) of red alder seeded naturally onto the site. Over the 6-year period of the study, the total N content of the soil increased an average of 56 kg•ha−1•year−1•. Foliar N concentration in Populus increased significantly from a mean late summer – early autumn value in the 2nd year (1982) of 0.69% N to a value of 2.06% N at the end of the seventh growing season. The mean annual height growth of the largest Populus averaged <0.5 m/year in the first 3 years, increasing to an average of over 1.0 m/year in the 5th and 6th years. Fertilizer treatments with N (as urea) and N + P (as urea plus treble superphosphate) placed in the soil near the individual Populus at a maximum rate of 5.3 g N/tree increased height growth in the year of fertilization (1982) and the following year (the response in height growth for the 2 years totaled 64%). After 1984, no significant effects of fertilizer on height growth, total height, or diameter were evident. Nitrogen fertilization significantly increased foliar N concentration (1.54% N with the highest N treatment vs. 0.69% N in the control) in the year of treatment only. Phosphorus fertilization had no significant effect on growth or foliar P concentration. At 6 years, only 2% of the Populustrichocarpa Torr. & Gray clone and 13% of the tallest Populus hybrid were equal to or above the mean height of alder dominants and codominants (6.2 m). Additionally, the diameter growth of Populus was severely limited: the trees had only 8% of the cross-sectional area of "normal" trees for their height. Results indicated that on sites of low N such as the mudflow, Populus may not compete satisfactorily in mixture with alder. Such behavior is in sharp contrast to sites of high N, where red alder cannot compete with Populus.


1990 ◽  
Vol 14 (2) ◽  
pp. 73-76 ◽  
Author(s):  
Mary L. Duryea

Abstract Top pruning, growing-season fertilization, and fall fertilization were investigated in a Florida nursery to determine the effects on crop yield, morphology, nutrition, and field performance. Top pruning improved crop yield by reducing the number of cull seedlings. Top-pruned seedlings were smaller in diameter, height, and weight and had an increased number of multiple tops. In the field, top-pruned seedlings had the same survival and height growth, and after 3 years the percentage with multiple tops was the same as nonpruned seedlings. From these results, top pruning seems to be a nondetrimental practice for controlling height and producing a uniform crop in the nursery. Reducing growing-season fertilization slightly decreased shoot height, but not as much as top pruning. Also, these seedlings had reduced foliar nitrogen (N) concentration and content and grew less after 1 year in the field indicating that cutting back on N in the nursery may not be a beneficial way to control height. Fall fertilization in the nursery increased N in seedlings but did not affect growth or survival in the field. South. J. Appl. For. 14(2):73-76.


1991 ◽  
Vol 21 (11) ◽  
pp. 1589-1595 ◽  
Author(s):  
Wendell P. Cropper Jr. ◽  
Henry L. Gholz

Respiration of needles and surface fine roots was measured in a north central Florida slash pine (Pinuselliottii Engelm. var. elliottii) plantation. A controlled temperature chamber system was used to estimate respiration rates and Q10 values of insitu tissues over a range of 10 to 35 °C. Respiration rates did not differ significantly among seasons, fertilized versus unfertilized plots, or time of day in a diurnal time series (needles). Needle respiration from the lower canopy was less than that from the upper canopy. Fine root respiration measurements were consistent with previously made estimates based on soil CO2 partitioning and trenched plots.


2009 ◽  
Vol 39 (5) ◽  
pp. 1024-1035 ◽  
Author(s):  
Monica G. Turner ◽  
Erica A.H. Smithwick ◽  
Daniel B. Tinker ◽  
William H. Romme

Understanding nutrient dynamics of young postfire forests may yield important insights about how stands develop following stand-replacing wildfires. We studied 15-year-old lodgepole pine stands that regenerated naturally following the 1988 Yellowstone fires to address two questions: (1) How do foliar nitrogen (N) concentration and total foliar N vary with lodgepole pine density and aboveground net primary production? (2) Is foliar N related to litter production and to rates of gross production, consumption, and net production of soil NH4+ and NO3–? Foliar N concentration of new lodgepole pine needles averaged 1.38%; only stands at very high density (>80 000 trees·ha–1) approached moderate N limitation. Foliar N concentration in composite (all-age) needles averaged 1.08%, varied among stands (0.87%–1.39%), and declined with increasing tree density. The foliar N pool averaged 48.3 kg N·ha–1, varied among stands (3.6–218.4 kg N·ha–1), and increased with aboveground net primary production. Total foliar N was not related to laboratory estimates of net production of NH4+ or NO3– in soils. Lodgepole pine foliage is a strong N sink, and N does not appear to be limiting at this early successional state. The initial spatial patterns of postfire tree density strongly influence landscape patterns of N storage.


1991 ◽  
Vol 18 (1) ◽  
pp. 37 ◽  
Author(s):  
DW Sheriff ◽  
EKS Nambiar

Potted Eucalyptus globulus Labill. seedlings were grown in sand with added inorganic nutrients. Three treatments were applied: (1) inorganic nitrogen was added regulary (N2), (2) in a small initial quantity only (N1) and (3) after a period of N deficiency (N3); other nutrients were supplied regularly. Biomass increment, foliar nutrient concentrations and gas exchange of leaves were measured. Carbon assimilation, N uptake, growth, and leaf production and expansion were all greater at higher N. Partitioning of dry matter to roots and tops of seedlings was unaffected by treatment. Carbon assimilation and diffusive conductance were linearly related at saturating light and were positively associated with foliar N concentrations; intercellular CO2 partial pressures were constant at c. 246 μbar. The relationship between carbon assimilation and foliar N concentration was better when calculated per leaf weight than per leaf area. Dark respiration was positively associated with foliar N concentration. Following refertilisation of N-deficient seedlings, foliar N and carbon assimilation increased rapidly; about 20 days later N uptake declined and seedling biomass started to increase. Instantaneous transpiration efficiency [c. 5 mmol (CO2) mol-1 (H2O)] was not significantly affected by foliar N concentration or treatment. Instantaneous nitrogen use efficiency of leaves: (rate of carbon assimilation)/(leaf N content) was greater at higher N. In contrast to the literature, there was no simple relationship between nitrogen use efficiency of whole seedlings (biomass gain)/(nitrogen concentration) and seedling N. Instantaneous transpiration and nitrogen use efficiencies were generally high compared with values published for many woody plants. A simple model predicted that, with no environmental constraints, exposed mature leaves with high N (1.5 mmol g-1) assimilate 5.4 times more carbon than similar leaves with low N (0.5 mmol g-1). Night respiration of foliage is a greater proportion of daily carbon balance for leaves with low N. When environmental factors constrain carbon assimilation foliage with high N is most affected.


1988 ◽  
Vol 12 (1) ◽  
pp. 28-32 ◽  
Author(s):  
D. L. Rockwood ◽  
G. M. Blakeslee ◽  
G. A. Lowerts ◽  
E. M. Underhill ◽  
S. W. Oak

Abstract Seedlings or ramets from 224 slash pine (Pinus elliottii var. elliottii Engelm.) clones were evaluated for resistance to the pitch canker fungus Fusarium moniliforme var. subglutinans Wollenw. & Reink. (FMS). Heritabilities and associated genetic gains calculated in five field tests suggest that pitch canker incidence can be reduced through appropriate genetic strategies. Three short-term strategies may be used to reduce incidence: use of an east-central Florida seed source, use of seed from resistant clones in existing orchards, and use of seed from seed production areas developed in epidemic areas. Longer term strategies involving new clonal orchards are predicted to decrease incidence significantly. Pitch canker resistance does not appear to be genetically related to good growth or to resistance to fusiform rust (Cronartium quercuum [Berk] Miyabe ex Shirai f. sp. fusiforme). South. J. Appl. For. 12(1):28-32.


1990 ◽  
Vol 20 (11) ◽  
pp. 1766-1772 ◽  
Author(s):  
J. F. Gleason ◽  
M. Duryea ◽  
R. Rose ◽  
M. Atkinson

Ponderosa pine (Pinusponderosa Laws.) from two seed zones in central Oregon were grown at two nurseries where they were subjected to fall applications of N, N + K, or no fertilizer. For one seed zone, foliar N concentration increased from 1.47 to 1.53% for the N application and to 1.57% for N + K application. For the other seed zone, seedlings did not show any differences in foliar N after nursery fertilization. Seedlings that received the N application appeared to be less susceptible to frost damage, but nursery fertilization had little or no effect on seedling morphology or bud break. One month after outplanting 2 + 0 seedlings back to their respective seed-zone sites, slow-release fertilizer pellets were placed 10–13 cm from half the trees. Soils at the outplanting sites differed in mineral content, percent organic matter, and pH. The nursery-fertilized seedlings with increased N concentration grew more than control seedlings during the first season. Field-fertilized seedlings at the less fertile field site grew more in the second and third growing seasons, indicating that field fertilization after outplanting is more effective on nutrient-poor sites. Soil fertility had a greater impact on seedling performance than did nursery- and field-fertilizer treatments. At the less fertile site, N concentration decreased by 14% during the first growing season and increased by 22% during the second season, whereas at the more fertile site it increased during both the first season (12%) and the second season (6%). Seedlings at the more fertile site almost doubled in height in the 3rd year and were more than 20 cm taller than those at the other site.


1984 ◽  
Vol 8 (2) ◽  
pp. 99-101 ◽  
Author(s):  
Hans Riekerk

Abstract The poorly-drained sandy soil of a small watershed in north-central Florida was amended with 56 dry tons/acre of coal-ash, bedded at 6-foot spacing, and planted to seedlings at 3-foot intervals. First-year growth of Casuarina cunninghamiana or Australian pine was better than on the nonamended control. The exceptional freeze of the winter of 1982 killed about 70 percent of the trees, but surviving individuals continued significantly improved growth rates as compared to the control. Replanting with Eucalyptus viminalis showed no better growth than the control. Dissolution of bases from the ash neutralized the normally acid soil and runoff water. As a consequence, concentrations of heavy metals in runoff were diminished.


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