Preliminary DRIS norms for coastal Douglas-fir soils in Washington and Oregon

1995 ◽  
Vol 25 (2) ◽  
pp. 208-214 ◽  
Author(s):  
J.S. Shumway ◽  
H.N. Chappell
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Integrated System ◽  
N Fertilizer ◽  
Soil Test ◽  
Fertilizer Response ◽  
Response Data ◽  
Limiting Nutrient ◽  
Diagnostic Work

The Diagnosis and Recommendation Integrated System (DRIS) has been used successfully in agricultural crops and holds promise for use in forest stands. This study used soil tests to develop DRIS norms and evaluate their effectiveness in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) forests. DRIS norms for nitrogen, phosphorus, potassium, and calcium were developed using soil test and site index data from 72 soil series that commonly support Douglas-fir in western Washington. The norms were tested using soil test and stand basal area growth response data from 20 thinned and 30 unthinned N fertilizer test sites in coastal Washington and Oregon. Response to urea fertilizer in thinned stands averaged 34% and 43% for 224 and 448 kg N•ha−1, respectively, when N was identified as the most limiting nutrient. When N was not the most limiting nutrient, N response averaged 8% and 10% for 224 and 448 kg N•ha−1, respectively. Results were similar in unthinned stands and thinned stands, although response to fertilizer appeared to be slightly less in unthinned stands when N was the most limiting nutrient. DRIS correctly classified 25 of the 33 sites (76%) where N fertilizer increased growth by more than 15%. More importantly, 13 of the 17 (76%) sites that responded by less than 15% were correctly identified by DRIS. The results clearly indicate that N fertilizer response is dependent on the interactions (balance) between soil nutrients at a given site. Future soil diagnostic work needs to focus on techniques, like DRIS, that provide an assessment of these interactions.

Growth Response to Fertilization in Young Douglas-Fir Stands

1989 ◽  
Vol 4 (4) ◽  
pp. 116-119 ◽  
Author(s):  
Linda S. Heath ◽  
H. N. Chappell
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Intermediate Region ◽  
Fertilizer Response ◽  
Breast Height ◽  
Inverse Effect

Abstract Response surface methodology was used to estimate six-year volume growth response to 1 application of 200 lb nitrogen per acre in unthinned and thinned Douglas-fir (Pseudotsuga menziesii) stands of breast height age (bha) 25 years or less. Regional mean fertilizer response was 16% in unthinned stands and 20% in thinned stands. Site index had an increasingly inverse effect on response as basal area increased in both unthinned and thinned stands. Response varied little over site index in regions of low basal area, decreased moderately as site index increased in the intermediate region, and decreased rapidly in the high basal area region. West. J. Appl. For. 4(4):116-119, October 1989.

Prediction of Douglas-fir fertilizer response using biogeoclimatic properties in the coastal Pacific Northwest

2014 ◽  
Vol 44 (10) ◽  
pp. 1253-1264 ◽  
Author(s):  
K.M. Littke ◽  
R.B. Harrison ◽  
D. Zabowski ◽  
M.A. Ciol ◽  
D.G. Briggs
Keyword(s):  
Pacific Northwest ◽  
Pearson Correlation ◽  
Regression Tree ◽  
Correlation Coefficients ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Annual Increment ◽  
Fertilizer Response ◽  
Boosted Regression Tree

Fertilizer response of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) has been related to site and soil properties in the past, but the models have explained only about half of the variation in these investigations. Fertilizer response and percent response after two years were examined, according to mapped and measured biogeoclimatic variables, for 71 Douglas-fir installations in the coastal Pacific Northwest. Paired-tree installations consisted of 12–20 pairs of Douglas-fir trees with one tree fertilized with urea at 224 kg N·ha−1. Pearson correlation coefficients and boosted regression tree (BRT) models were used to determine the best predictor variables and models of Douglas-fir fertilizer response. The BRT models, using the combination of mapped and measured variables, performed the best for predicting fertilizer response. Basal area and volume responses were most related to high forest floor and surface soil carbon to nitrogen ratios. Basal area mean annual increment (MAI) and site index were both negatively correlated with fertilizer response. Also, low basal area MAI was the most important tree measurement for predicting fertilizer response in the BRT models. Installations with many of the predictors from the BRT models (>66% of the model criteria) were found to have a significantly greater fertilizer response than installations with only a few predictors (<33% of the model criteria). These findings support the use of these models for predicting fertilizer response of similar Douglas-fir stands in the coastal Pacific Northwest.

Stand growth responses after fertilization for thinned lodgepole pine, Douglas-fir, and spruce in forests of interior British Columbia, Canada

2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Growth And Yield ◽  
Growth Responses

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.

scholarly journals Modeling Response to Midrotation Nitrogen and Phosphorus Fertilization in Loblolly Pine Plantations

2000 ◽  
Vol 24 (4) ◽  
pp. 207-212 ◽  
Author(s):  
Ralph L. Amateis ◽  
Jiping Liu ◽  
Mark J. Ducey ◽  
H. Lee Allen
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Phosphorus Fertilization ◽  
Nitrogen And Phosphorus ◽  
Fertilizer Response ◽  
Nonlinear Regression Models ◽  
Dominant Height ◽  
Volume Response ◽  
Pinus Taeda L

Abstract Data from a fertilizer response study in loblolly pine (Pinus taeda L.) plantations at different sites in the southeastern United States were used to develop response models for dominant height and basal area following midrotation nitrogen (N) and phosphorus (P) fertilization. Nonlinear regression models developed from the data predict total cumulative response as a function of the interaction of N and P application rates, drainage class of the site, stand conditions when fertilized, and time since fertilization. Stand variables that were found to be significant predictors of response included site index, age, basal area, number of surviving trees, and dominant height at fertilization. Dominant height response was significantly greater on poorly drained sites than on other sites. Basal area response to P was significantly less on poorly drained sites and significantly greater on well drained sites. These models can be coupled with unfertilized baseline models to estimate volume response to midrotation fertilization. South. J. Appl. For. 24(4):207-212.

Nitrogen Fertilizer Response of Rocky Mountain Douglas-Fir by Geographic Area Across the Inland Northwest1

1991 ◽  
Vol 6 (4) ◽  
pp. 94-98 ◽  
Author(s):  
James A. Moore ◽  
Peter G. Mika ◽  
James L. Vander Ploeg
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Rocky Mountain ◽  
Geographic Area ◽  
Douglas Fir ◽  
Fertilizer Response ◽  
Inland Northwest ◽  
Geographic Regions ◽  
Nitrogen Treatments ◽  
Area And Volume

Abstract Response to nitrogen fertilization treatments in Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) differed significantly among geographic regions within the inland northwest. Gross basal area and volume growth on fertilized plots were significantly greater than growth on controls for all geographic regions, but only in northern Idaho and central Washington was gross response significantly greater on 400 lb/ac N plots than on 200 lb N plots. Net basal area and volume growth on treated plots in Montana, central Idaho, and northeast Oregon were not significantly greater than the controls for either nitrogen treatment. Analysis of 2-year periodic basal area increment indicated that, while response did decline through time, treated plots continued to produce more gross growth than control plots 6 years after treatment. Similar operational nitrogen treatments applied to the Douglas-fir population sampled in this study should produce gross responses exceeding 10% after 6 years three out of four times. West. J. Appl. For. 6(4):94-98.

ECONOMICS OF N-FERTILIZATION OF DRYLAND GRASSES FOR HAY PRODUCTION IN SOUTHWESTERN MANITOBA

1990 ◽  
Vol 70 (2) ◽  
pp. 559-563 ◽  
Author(s):  
W. P. McCAUGHEY ◽  
E. G. SMITH ◽  
A. T. H. GROSS
Keyword(s):  
Sandy Loam ◽  
Fertilizer Application ◽  
N Fertilization ◽  
N Fertilizer ◽  
Grass Species ◽  
Fertilizer Response ◽  
Intermediate Wheatgrass ◽  
Response Data ◽  
N Supply ◽  
Application Rates

An economic analysis was conducted on N fertilizer response data of four dryland grass species on two soil types. Clay-loam soils were more productive than sandy-loam soils. The N supply required to obtain optimum economic yield was determined and results showed that producers must increase N fertilizer application rates over current rates of application in order to maximize profit.Key words: Bromegrass, crested wheatgrass, intermediate wheatgrass, Russian wild ryegrass, nitrogen fertilizer, economics

Predicting Fertilizer Response in Established Loblolly Pine Plantations With Basal Area and Site Index

1982 ◽  
Vol 6 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Howard W. Duzan ◽  
H. Lee Allen ◽  
R. Ballard
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Economic Benefits ◽  
Fertilizer Treatment ◽  
Nutrient Deficiencies ◽  
Fertilizer Response ◽  
Wide Range ◽  
The Difference ◽  
Pinus Taeda L

Abstract In a wide range of loblolly pine (Pinus taeda L.) plantations, very few of which were suffering from severe nutrient deficiencies, response to fertilization was related to stand conditions. Gross and net volume increment equations were developed using basal area, site index, and fertilizer treatment as predictor variables. Response to fertilization was calculated as the difference between growth estimates for control and fertilized stands at given levels of basal area and site index. Predicted 5-year volume response from fertilization with 100 lbs N/A + 50 lbs P/A is given for a range of basal area and site index levels for both the Coastal Plain and Piedmont regions. The information provided will enable the forest manager to choose stands with the greatest potential for response, and to determine the economic benefits of fertilization.

A Growth and Yield Model for Improved Eastern Cottonwood Plantations in the Lower Mississippi Delta

1991 ◽  
Vol 15 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Quang V. Cao ◽  
Kenneth M. Durand
Keyword(s):  
Populus Deltoides ◽  
Mississippi Delta ◽  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Annual Increment ◽  
Yield Model ◽  
Eastern Cottonwood ◽  
Volume Yield ◽  
Growth And Yield Model

Abstract A compatible growth and yield model was developed based on remeasurement data collected from 183 plots on unthinned improved eastern cottonwood (Populus deltoides Bartr.) plantations in the lower Mississippi Delta. The Sullivan and Clutter (1972) equation form was selected for predicting cubic-foot volume yield and projecting volume from site index and initial age and basal area. Yield equations explained 97% and 94%, respectively, of the variations in total outside bark and merchantable inside bark volumes. Mean annual increment of merchantable volume culminated between 8 and 15 years, depending on site index and initial basal area. South. J. Appl. For. 15(4):213-216.

scholarly journals Relationship between environmental factors and site index in Douglas-fir plantations in central Italy

1998 ◽  
Vol 110 (1-3) ◽  
pp. 195-207 ◽  
Author(s):  
Piermaria Corona ◽  
Roberto Scotti ◽  
Neri Tarchiani
Keyword(s):  
Environmental Factors ◽  
Central Italy ◽  
Site Index ◽  
Douglas Fir

Relationship of soil phosphorus fractions to phosphorus soil tests and fertilizer response

2003 ◽  
Vol 83 (4) ◽  
pp. 443-449 ◽  
Author(s):  
R. H. McKenzie ◽  
E. Bremer
Keyword(s):  
Available P ◽  
Soil Test ◽  
Strongly Correlated ◽  
P Fractions ◽  
Soil Tests ◽  
Fertilizer Response ◽  
Inorganic P ◽  
Soil P ◽  
P Fertilizer ◽  
Soil Test P

Soil tests for available P may not be accurate because they do not measure the appropriate P fraction in soil. A sequential extraction technique (modified Hedley method) was used to determine if soil test P methods were accurately assessing available pools and if predictions of fertilizer response could be improved by the inclusion of other soil P fractions. A total of 145 soils were analyzed from field P fertilizer experiments conducted across Alberta from 1991 to 1993. Inorganic P (Pi) removed by extraction with an anion-exchange resin (resin P) was highly correlated with the Olsen and Kelowna-type soil test P methods and had a similar relationship with P fertilizer response. No appreciable improvement in the fit of available P with P fertilizer response was achieved by including any of the less available P fractions in the regression of P fertilizer response with available P. Little Pi was extractable in alkaline solutions (bicarbonate and NaOH), particularly in soils from the Brown and Dark Brown soil zones. Alkaline fractions were the most closely related to resin P, but the relationship depended on soil zone. Inorganic P extractable in dilute HCl was most strongly correlated with soil pH, reflecting accumulation in calcareous soils, while Pi extractable in concentrated acids (HCl and H2SO4) was most strongly correlated with clay concentration. A positive but weak relationship as observed between these fractions and resin P. Complete fractionation of soil P confirmed that soil test P methods were assessing exchangeable, plant-available P. Key words: Hedley phosphorus fractionation, resin, Olsen, Kelowna

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