Nutrient Limitations to Growth of Westside Douglas-fir Forests: A Look Beyond Nitrogen
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Transcript of Nutrient Limitations to Growth of Westside Douglas-fir Forests: A Look Beyond Nitrogen
Nutrient Limitations to Growth of Nutrient Limitations to Growth of Westside Douglas-fir Forests: Westside Douglas-fir Forests:
A Look Beyond Nitrogen A Look Beyond Nitrogen
Doug MaguireDoug MaguireDepartment of Forest ScienceDepartment of Forest Science
Oregon State University Oregon State University
Steve PerakisSteve PerakisFRESCFRESCUSGS USGS
Rick FletcherRick FletcherDepartment of Forest ResourcesDepartment of Forest Resources
Oregon State University Oregon State University
Doug MainwaringDoug MainwaringDepartment of Forest ScienceDepartment of Forest Science
Oregon State UniversityOregon State University
BackgroundBackground
• Trials originally of interest to members of the Trials originally of interest to members of the Swiss needle cast cooperativeSwiss needle cast cooperative– Fertilization has been investigated as one of the tools Fertilization has been investigated as one of the tools
to combat SNCto combat SNC– Previous SNC fert studies have generally included Previous SNC fert studies have generally included
N, either as single-nutrient treatments or blends:N, either as single-nutrient treatments or blends:• Menasha trialsMenasha trials• Plum Creek trialsPlum Creek trials• VMRC trialsVMRC trials• Balanced Fertilizer trialsBalanced Fertilizer trials
F R = 1 . 5
F R = 2 . 5
F R = 3 . 5
-20
-10
0
10
20
30
40
1 1.2 1.4 1.6 1.8 2 2.2 2.4
% foliar N
5-yr
Vol
gro
wth
cha
nge
with
trt (
%)
BackgroundBackground
• Studies suggest that nitrogen may be Studies suggest that nitrogen may be problematic in SNC-infected standsproblematic in SNC-infected stands– Lack of response to N in previous fert trialsLack of response to N in previous fert trials– Negative correlation between foliage retention and Negative correlation between foliage retention and
foliar Nfoliar N– N from fertilization was found to be directly N from fertilization was found to be directly
responsible for increased the fungal nitrogen levels responsible for increased the fungal nitrogen levels and fungal fruiting, and thus, disease severity and fungal fruiting, and thus, disease severity
Leaf Retention as a Function of Leaf N Concentration
0
1
2
3
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0.8 1 1.2 1.4 1.6 1.8Leaf Nitrogen, %
Leaf
Ret
entio
n, Y
ears
BackgroundBackground
• Studies suggest that nitrogen may be Studies suggest that nitrogen may be problematic in SNC-infected standsproblematic in SNC-infected stands– Lack of response to N in previous fert trialsLack of response to N in previous fert trials– Negative correlation between foliage retention and Negative correlation between foliage retention and
foliar Nfoliar N– N from fertilization was found to be directly N from fertilization was found to be directly
responsible for increased the fungal nitrogen levels responsible for increased the fungal nitrogen levels and fungal fruiting, and thus, disease severity and fungal fruiting, and thus, disease severity
BackgroundBackground
• Proposed study went through several iterations Proposed study went through several iterations to meet the needs of participantsto meet the needs of participants– How to include non-SNC Coop membersHow to include non-SNC Coop members– Fixed area vs. individual tree plotsFixed area vs. individual tree plots– TreatmentsTreatments
Fertilization Trials
16 locations, 12 landowners
Cascade Timber Giustina Green Diamond (2) Hampton (2) Lone Rock Menasha (2) ODF OSU Port Blakely Starker West Fork Timber Weyerhaeuser (2)
Study design
• Individual tree plots (1/40th acre)
• 10 plots per treatment
• 5, 7, or 8 treatments per site
• 50, 70, or 80 plots per site 18.6 ft
Target stands
• Target stands– 20 yrs of age (+/- 5 yrs)– 300 tpa (+/- 100 tpa)– No pct or fertilization in last 8 years– < 20% salal cover– Good road access– Relatively flat– Limited brush cover– Nearby donut source
Target stands
• Target stands– 20 yrs of age (+/- 5 yrs)– 300 tpa (+/- 100 tpa)– No pct or fertilization in last 8 years– < 20% salal cover
Foliage retention
QMD (inches) Ht (ft) CR Age TPA Foliar N% pH
mean 2.75 11.4 66.4 0.64 19.2 320 1.37 1.37max 3.65 15.4 92.1 0.79 28.4 625 1.59 1.59min 1.62 7.7 42.4 0.47 13 176 1.13 1.13
TreatmentsTreatment Form Amount Reason for inclusion
Control - - - - Statistical reference for treatmentsN Urea 224 kg N / ha Standard approach, examine effects of
adding N to N-rich sites
Lime CaCO3 1000 kg Ca / ha Elevates pH, reduces Al, adds Ca: compare to Ca-only treatment
Ca CaCl2 100 kg Ca / ha Low soil and foliar Ca is common at our sites, attributable to high soil N
P NaH2PO4 500 kg P / ha Can limit growth in highly weathered soils, some sites have P-fixing soils
Kinsey Blend Site specific Scientific and industry interest in overall nutritional limits to productivity
Fenn Blend Site specific Scientific and industry interest in overall nutritional limits to productivity
Treatments, Kinsey
WF CTC HAGRSTR GDE GDH PB OSU ODF MNN MNS HAKMAP 250 250 250 250 250 250 250 250 250 250 250K2SO4 200 500 125 125 175 425Sulfur 95 105 90 95 90 95 95 95 90 85 95 80Boron 15 15 15 15 10 15 15 10 5 7ZnSO4 20 20 20 15 20 10 10 20 20 0CuSO4 20 10 10 20 30 20 20 20 25 25 25 25FeSO4 400 325 400 400 425 400 400 400 400K-Mag 400 300 300 750 400 324 400 400MnSO4 100MgSO4 300Cal lime 350 4850 1900 2800 1200 1200 950 2100 2250 950 2250 1500Dol lime 1200 4150 2700 2500 3000 3100 2150 3200 1700 2100
Values given in lbs/acre
Treatments, Fenn
Values given in lbs/acre
WF CTC HAGR STR GDE GDH PB OSU ODF MNN MNS HAKNitroform 476 169.6 138.4 297.5 169.6 59.6 536.1 700.3 169.6
K-Mag 568 340.9 341 681.7 340.9 227.6 399.6 214.3 340.9
Gypril 249.9 104 624.8 249.9 312.8 74.9 476.4 249.9
Ammonium sulfate 41.6 41.6 41.6
ZnSO4 273.5 139.9
Na Molybdate 4.1 4.2
InstallationChoose appropriate dom/codom measure tree on 1 chain grid
Subject tree measurements: Dbh Ht Hllb Sapwood width Diameter @ 5.5 m Fifth-whorl foliage retention
1/40-ac plots centered on measure tree (radius=18.6 ft)
Installation
Plot-level measurements: Dbh of all trees within plot
Installation
Treatment-level data (composite from 10 plots): Foliage (needles from current shoots) Soil (from 2 soil cores)
Each treatment randomly assigned
to 10 plots
ScheduleSchedule• 2006-07
– Install and measure plots– Sample soil and foliage– Fertilize (February-March)
• 2007-08– Sample soil and foliage– Apply lime to Kinsey treatments
• 2009-10– Measure plots– Sample soil and foliage
• 2012-13– Measure plots