Nutrition at

(1)

<71\\

'-

Presentations given at the Annual Meeting of the

Intermountain Forest Tree Nutrition cooperative

April, 1985

(2)

Table of Contents

Two-year growth response results for the 1981 and 1982 installations using the experimental design.

By Peter Mika.

A predictive model of basal area growth response to nitrogen treatments. By Jim Moore.

Additional comparisons of growth response to treatment by soil parent materials using the predictive model. By Jim Moore.

1

28

53

I. Mineralizable-nitrogen as a predictor of

treatment response. II. Other mineral nutrients--

are they also limiting growth! By Kurt Pregitzer. 56 Soil moisture holding capacity for selected parent

materials. By Jim Mital. 79

Douglas-fir height growth and site index curves-- testing and refinement using IFTNC stem analysis data. By Jim VanderPloeg.

Information requirements for an operational fertilization program. By John Olson.

Applied research needs. By John Shumway.

Basic research needs and opportunities.

By John Mandzak.

83

111

125

127

(3)

Peter Mika, Data Analyst I.P'.T.N.C.

I. Review of experimental set-up

A. Distribution of installations by reqion and year B. samplinq qoals

1. 2nd qrowth, even-aqed, manaqed stands of Df 2. Ranqe of aqes, tree sizes, densities, site conditions

Conditions sampled:

Range Mean

Aqe 27 to 100 65 years

SA 48 to 272 142 ft2/A

DSH 5.8 to 15.3 10.3 inches

site Index 37.1 to 108.0 68.7 ft @50 yrs

% Df 87.5%

-"-

Plot set-up

II. Results from analysis of experimental desiqn A. Model #1

1. OVerall model statistics

2. Details on factors influencinq treatment response a. Reqional differences (at SA = 150 ft2/A)

(i) Absolute 2 year BAI by treatment and reqion

(4)

2

Good qeneral qrowth in N Idaho Poor qrowth in HE Oreqon

General increase from control to N treatment across all reqions (ii) Difference between control and N

treatment by reqion

Larqe response of N. Idaho and Central Washinqton

Larqe chanqe from 200 to 400 in Central Washinqton

(iii) %chanqe [(treatment-control/control]

Relative response about the same over all reqions, except for Central Washinqton

b. SA differences

(i) %response decreases as initial BA

increases

(ii) 400 # response seems to converqe to

200# response at hiqher SA ( 200

ft2/A)

3. Details on factors influence underlyinq qrowth rates

a. SA differences

(i) OVerall, as SA increases, qrowth/acre also increases - effect of increased stockinq level

(ii) Yearly differences

(5)

"

.,

3

1981 - decreasinq rate of BAI/BA at hiqher BA

1982 - linear across the ranqe of BA's b. Year differences - vary by reqion

(i) North Idaho, Central Idaho, HE Oreqon, Central Washinqton - hiqher qrowth rates on 1982 installation

(ii) HE Washinqton - growth rates similar in both years

(iii) Montana - hiqher qrowth rates on 1981 installation

SCI Hodel #2

Reqion x treatment and BA x treatment replaced by Min N x treatment

1. OVerall model statistics

2. Factors influencinq treatment response a. Min N differences

(i) Converqence of treatment response to control levels as Min N increases (ii) Converqence of 400# to 200# on Min N

increases

3. Factors influencinq underlyinq qrowth rates a. Min N

(i) Growth on control plots shows trend of increasinq qrowth with increasinq Min-

N

(6)

(ii) Basically no trend (zero slope) for SAX versus Min N on treated plots

4

(7)

Nur·1BER OF INSTALLATIONS

YEAR OF INSTALLMENT

REGION 1 1981 1982 TOTAL

NORTHERN IDAHO S 14 19

CENTRAL IDAHO 3 S 13

MONTANA 8 8 16

NE OREGON 6 2 3

CENTRAL WASHINGTON 9 9 ·18

NE WASHINGTON 9 7 16

"'" ^TOTAL ^lIS ^LJS 90

5

(8)

DESIGN NODEl 1

IN

(BAD

=

F ( YEAR , REGION , YEAR X REGION, INSTAllATION ( YEAR REGION )

BLOCK ( YEAR REGION INSTAllATION ) TREATMENT

REGION X TREATMENT

6

BA X TREATMENT BA2 X TREATMENT

BA X YEAR BA2 X YEAR )

R2

⁼

0.9025 f1SE = ^0.0243 cv -

^~.^....

. ⁸⁶

¹¹^,^o

(9)

) ^)I ^j .; ;) ) ) ) J ^j ^j

2 YEAR BASAL AREA INCREMENT

BY TREATMENT AND REGION BAI

20

15

5

o

II - I

I ^I

I : _{J.lJ__} I

C 2 4 0 0 0

N 0 0 T

C 2 4 C 2 4

a

^{f2J f2J}

a

0 f2J

N f2J 0 N f2J f2J

T T

C 2 4 C 2 4 C 2 4 C 2 4 0 0 0 0 0 0 0 0 0 0 0 0 N 0 0 N 0 0 N 0 0 N 0 0

T T T T ^TRTMENT

MEAN N 1D MONT C 1D NE OR C UA NE UA REGION

^-..J

(10)

~ ⁾ ⁾ ⁾ ⁾ ^j ^~ ⁾ ⁾ ii ^j

SAl INCREASE OVER CONTROL

BY TREATMENT AND REGION RESPONSE

5

TRTMENT

2 4

o

0

o

⁰

2 4

o

^fa

o

⁰

2 4

fa 0

o

⁰

2 4

o

⁰

o

0

2 4

o

0

o

0 2 4

o

0

o

0

2 4

o

⁰

o

⁰

2

j

I I

I :

o

~lJ t.. ^l

4

MEAN N 1D ^MONT C 1D NE OR C UA NE UA REGION

_en

(11)

J )

iii

;)

)

}

.Jl

}

j )

....

)

".

2 YEAR BASAL AREA INCREMENT

G£OGRAPHICAl R£GIONbC£NTRAl IDAHO

18

8~

6 B A I

i

\0

~ ¹

^{98/, 200}

^lBs

~

¹^982,

^CONTROL

~

^{1982, 400}

^lBs

..." 19

8', CONTROL fJ-s-{J 1981, 400

las

--.

1982, 2ae

las

1-~

'" ,- , y" y"", , '""p

~-'-"

"T", -, "' -,- ,-,",-," ,_-.-r

~

r1-'-'-'-'-"r-.-_,"r -.-,_. ,_,

"T""T-'-'-'-'-'-'~T-r-.-.-,..

7S ,

0a

12S ,

sa ,

7S 2ae 22S

INITIAL BASAL AR£A (SO FT) LEGEND:

YEAR_TRT

-

(12)

j

;J

;,

;)

)

j

i

j

J

,.

^~

j

---~---~-~--- ---.,.-

• •

2 YEAR BASAL AREA INCRtMENT

GE:OGRAPHICAL RE:GION:ONORTH IDAHO

16

e

6

B A I

o/-A

225

2ee

~

¹⁹

^{8', 2ee} ^LBS

~

¹⁹⁸^2,

^CONTROL

~~

1982, 4ee Las

4.

,- r-,.r-'~r-r--.-..._ ...

. ~ ^" ^• r-,-r-r""~-r'rr-"

, l "'-'-r-?'"l-r~.,...-..-.^__

7S

, ."

r"~"r-'''_''''-r-r-r''''''l_''J"-..-

^.

lee 12S. ISe 17s ...-...., ..._

INITIAL BASAL ARE:A (sa FT)

'-,.

^198',

CONTROL

IiJ.-B-a ,

^981, ^{41313 lBs}

---'-ft. '

⁹⁸^{2. 21313}

LBs

LtGE:ND, YE:AR_TRT

(13)

j ) ^;) ) j ^jj j} ij j J

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE OREGON

::#=

^M

)( = =

B A I

18

16

14

12

a

.;II

•

---e

•

r·~'1 ,-rr,-rT'rrr r','rT-,-r yy-,-r T Y'""l-r-r"'-r·TT"-'~·1-r"-'-r-""'T-r,·,-r"··"T·'-r-t"-'-'· i , , , I

75 100 125 150 175 20~ 225

INITIAL BASAL AREA esa

FT)

LEGEND: YEAR TRT

^{• • • 1981} ~

CONTROL

⁶ ^I) ^I) _{1981 "}

200 LBS

o 8 e 1981"

40fa LBS

^~ ^Q ⁰ _1982"

CONTROL

^I-'_I-'

.. .. ..

^1982, ^{2era LBS} )( )( )( 1982" 499 LBS

(14)

,...

tv

~

^{1981. 200}

^Las

~

¹⁹⁸^2.

^CONTROL

~.1-982.

^-400

^Las.

~

* •

~

)( 4(

. 8 . . .

... 1981. CONTROL

B-a-a

^{1981. 400}

Las

---. '982, 200

Las

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGI0N~CEN ~ASHINGTON

, ...,.". "-' ., ., , . "~ -" -,'''-r '-'-, -,...,.."

"-'''''''r-,-,-,.-,-,..

'r' ~

^-r...-"'r ... ' ,....,,..,..., _'-'-.,.

7& 100 125 150 175 200 225

INITIAL BASAL AREA (SO rT)

6

81.---= _

4'f B A I

j

jJ

)

);

;j

J

)

i).

J j

LEGEND: YEAR_TRT

-

(15)

) ^}; ) ) ]) _J^:,\ J ^.) ⁾ ^j j

18

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE YASHINGTON

16 14

1

12~

^. ^__^{- - - l...}

^..---==

~ ~ . ---=-~

I 10

8

6

4 T"-"'l,"Tf"' TT f ,-,- '"r",-ry-T"·""-rTT'TT....-r-r'l'''T''-r-r'''''-'-T"'··'-r·T

,·,·,.,.,-rTTT

75

lrara

125 150 175

200

225 INITIAL BASAL AREA esa FT)

LEGEND: YEAR TRT • ,. • 1981, CONTROL

^~ ^~ ^~

1981 , 200 LBS

o

⁰ ⁰

1981, 400 LBS

^~ ^Q ~

1982, CONTROL

^...w

.... * 1982, 2e0 LBS )( )( )( 1962, 400 LBS

(16)

;) ) ) ⁾ ^;) ) ) ) j j j

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=MONTANA 18

'6

'4 '2

G - _ _ C

all II:

v II It

~

--,..

_ "TT

6~!"I"r _ __~

.a-- _----a

... ....e;.-.----.

--

^...^-~'"

---

e--- ---

4 T-,-'-1-1" , -'-'-'''"r'^{0... ,-}^{r -,-}^{r ..}^{1 ,} ^{T ,-,} ^{0' -,}^{-.-r , ...}'-1-''''-'' •^-r^{-y- ..}^-rr-' -, '.--,-,·.··rr'·r'r"'''-'T

't-".,.,...

8]

B A I 1ra

75 100 125 150 175 200 225

INITIAL BASAL AREA (sa FT) LEGEND: YEAR_TRT ..-....-.. 1981; CONTROL

B-G-B

1981;

4f2J~

LBS

--*

1982; 200

LBS

.4) 9 4

G Q Q

)( )( )(

1981;

2f2J~

LBS 1982; CONTROL 1982;

4~0

LBS

...

~

(17)

DES IGN r'loDEL

2

LN

(BAI) =

F ( YEAR , REGION , YEAR X REGION, INSTALLATION ( YEAR REGION)

BLOCK ( YEAR REGION INSTALLATION) TREATMENT

15

MIN

N

R2 = ^0.9038

BA.x

^YEAR

BA2

^X ^YEAR

MIN

N

^X TREATMENT)

CV = 6.71%

(18)

) ⁾ j ⁾ ^j J ^J ^!) J ; ^j

18

16

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE WASHINGTON

143 h---

_.. ⁰ ^{- - .} ⁸ ^---,-I'"t---_^B ~

. . >=. . . .- - -- .~"fF:-- ~

-

_~

Q i - I I I

^Ii _~

B 12}-_... . _ . _ ..

_-~---_._-:.-:-.-.- ~ ==at " " • _~

A ., ... -

*

I I0-1 .. __ -

-=-__

^{_ C :}

..,

_{.---_.-} _. __

^{- 4 - - -}

-.

^=~

--:

.. _ - .⁰ Q__ . . . - 0 - - -

8-4.-·---

6

4 _TT'.'-'T_'"TT

'1'"

'T'r,-r'"TTrr,-rr, TO'-'TT' ,-"

'0'

'-'T",,-rrrTTll , , , , 1'l-""-l"~TTrlTf"1 I , ^{i i i}t 'TT'TI • I • I I II

10 20 30 4Ja 50 60 70 80 90 100

MINERALIZABLE NITROGEN (PPM)

LEGEND: YEAR __ TRT

^1It-

1tc--.

^{1981 "}

^CONTROL

^~ ^f) ^~ ^{1981 "}

^{200 LBS}

^...

a-e-a

1981 .,

400 LBS

^G ⁰ ^4· ^1962.,

CONTROL

^m

* *

^-ff- ^1962.,

^{200 LBS}

^K ^)E ^)E ^1982.,

^{400 LBS}

(19)

;; :; ⁾ ⁾ ⁾ ^2J J ⁾ ^iJ ⁾ ^j

18

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=CEN WASHINGTON

16-

14..:t-- _, ^------ ^{)( - - -}

--*"----)(~---

---..---.---.-.- -..---... ---..

==#=-_.=tF=-~~_."

• ^·==tt

12t=-- ----...

- ; 3 - - . _ -

====---:- .~

B -a---a---

_~ _~

-

A ----., _.._~--_^{.. ---- -}~-^{-- •. --}^{-6-' - -}~=--

: ⁱ

ⁱ

^:=-:::-itr

^~~--~

I t~l1---" _.-

_{_..--a---}

~

__

- - - O - - ". _---Itt---...---

.1.-_-- ..----*

81

¹

..

^-^...^-~-~----^{- ....----} ^• ^----*-

6~

"1",,

^{n n "}^{( ' H}^{n "}

'"'I" nn~

n " " , ' " n 'IT'.r. ·r'lr r "lTnnnnrrnnn-r.,.. r· .

tra

^2lCl ^3fa ⁴⁰ ^5~ ⁶⁰ ⁷⁰ ⁸¹²¹ ⁹⁰ ¹⁰¹²¹

MINERALIZABLE NITROGEN (PPM) LEGEND: YEAR_TRT

. - . - . 1981 J

CONTROL

~.. a 1981" 40121 LBS

---*_..

^1982" ^212J0

^LBS

~ ~ ~ 1961 J 200 LBS

-C-O-._+ 1962J

CONTROL

~-*""* 1 962.. 412Jf2J LBS

...

'-.I

(20)

j ) J ⁷ ^;) ⁾ ⁾ ⁾ ^:1 .1 ^j

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE OREGON

18

16

14

1

12

'-. )(

._--~-_

.. _-*-

>< -

---.- - ..- ..--.--- tt__

·-...----·--·w ::V===

--tF=.-~ ~

• ---·tt

-. --- .. _. a-- .. ---e----

"-"6---... - - - e - - - " ~ 8 -_ _{~_} _.. -.()-------.-.~.-..

.¥--- ^-oil;. -"':._,

^{- = -}^i!I ^• ^{r =} i!I

l

-1 _-_~-- ^Q ^Q ^- ^• --*

-ie-.. - _~---.-

-i .---~.,....- - -

6] .--.--. ^-

^- ^...

^---

-JIt---""*---

4 .

r^"r,r " ' r T lrrrTT" .. r r ,

rr

r .. , 'T' , 'T'-'·'.... ,...·'TTTTrr·n ...,.l'·r ,."." "'TTTrrr.,. TTrTrrrn...-rrTrT.,...I I I I r

B

A I 10

10

2ra 3ra

40 50

sra

70

8ra

⁹⁰

lrara

MINERALIZABLE NITROGEN (PPM)

LEGEND: YEAR_TRT

.~-..

1981.. CONTROL

~ ~

..

~

1981 .. 2rara LBS

_...

&-B--f}

1981.. 4f2J0 LBS

^Q ^Q ~

1982 .. CONTROL

^co

--* 1982 .. 200 LBS )( )( )( 1982.. 40ra LBS

(21)

;> J ⁾ ^;) ^j ⁾ ⁾

j ) j J

18

16 14

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=CENTRAL IDAHO

--- )( - ) ( )(

._"""-*~---

12i1r--. _-- - -._---tt--- 4t__--- ----

* 1t==::::=:::w=-

--¥- II = Jt B

:r--

^B

- - a - - - -

⁰ - - f 8 = t - - - -

A

r---~-- -- ^~ . ^-~_. ⁱ

:ij"==- 8 .~_o-,...---' - ' f j 8

==~

I 1fa ^Q 0 : :

=-_ _--~---

~ ⁰ ^31& ^- ^- ^,..

1 .-

^{1 ! - - -} ^~-

10 20 30 40 5fa 60 70 80 90 100

MINERALIZABLE NITROGEN (PPM)

LEGEND: YEAR_TRT ..-.... - .. t98 t" CONTROL ^~ ^{~ _.~} 1981 ~ 200 LBS ...

&-B--f.} t 981" 400 LBS ~ ^• ^-.Q. 1982" CONTROL ^\D

~-.. 1982~ 200 LBS )( )( )( 1982~ 400 LBS

(22)

:; ⁾ ^;) ⁾ ^} ^} ⁾ ^j

:} j j

18

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=MONTANA

16

14

t

2 -f B

A

_I :b- ..

^{-6--_. -} ^B - - - 6 - - - __

~ ~ ^{i : _._}

^II " . - ,

~

t

0r-f:"-_

^-/T--_ <> .- ^{·.h. "}

~

-- ^...

.t. ~

.I. _ - - - -

'

^.

---

~ ~

8-1 .... __- - - ..

_----..or.- ^-4?--.

*= ¥ = = " ..

^.M'

-- --. )t-:-.=...~ . ... -:-0_. -_ . •_~----^-'-'. ^...w-=- __:::::_.:=: ...:..: ..._ ~

.JII -~=---.===-.^0°·.· tt---.. -'"W----_^o^{. - .}

6

00--

~---"-.-.-

- -...- - - 0---0--.---<>---- _ ...- - -

~

_ _.o_e

4 , J"' ,,r, " '1"1"11

'0' ,

,o,r" r-IT11"O'O'Tr'r," ' T I"l-rrTlT'Tn-r,-r,"-"" ^T-TT,^{T T l '} r r,o.-" .. ,rrr,,,,,,orl • I , ,ITTTJ

1ra 2ra 3ra

⁴⁰ ⁵⁰

sra

^7ta ⁸⁰ ^9ta ^tta0

MINERALIZABLE NITROGEN (PPM) LEGEND: YEAR_TkT

--~-.

t981

^J

CONTROL

a-a-·-e

1981

^J ^40ta

LBS

• .# -* 1982J

200 LBS

+-~-~ I 98 1^J

200 LBS

4-~~ 1982J

CONTROL

W v~ t982~

400 LBS

I\.)

o

(23)

) :; ^)I

) ) } ⁾

) ) ) J

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NORTH IDAHO

\0 20 30 ⁴⁰ ⁶⁰ ⁶⁰

70 80 ^9ltl ^1ltl0

MINERALIZABLE NITROGEN CPPM)

LEGEND: YEAR_1RT ^~ ^{• • 198\J} CONTROL ⁺

e

_~ '96\J 200 LBS ^IV

a--e---9 \

98' J 400 LBS

..cr ^Q ~ '982 .. CONTROL ^~

.-._*

'982 .. 200 LBS

*

^X

*

\962 .. 400 LBS

_...---

_--4---

e----'- ______

. ..---....--

~

:1 41

1

n'" n , n Inn ...._.,., Tn,., ,-., , ' p n , ",.

-nrn-

n "'''''T'-n ....n",-n-rrrrn-rp ,...n"'-' • • , rrTTTt-nT

B

A I \0

(24)

) ) .> ^;) ^.) ⁾ ^:1 ^") ^;) ^.I ^J

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE UASHINGTON

18

16

• __:t

~

r1

'OJ -

---a--- --

~

..

e---

r----

8

I'll

12

J

~ ~

I 10 6

(25)

)

J

.)

)

;)

j)

)

j

tv t.J j )

)

>( - - k

if •

~

^1981. ²⁰⁰

^lBS

~

¹⁹⁸^2. ^CONTROL

~

¹⁹⁸^2. ⁴⁰⁰ ^lBs

~ ....---

~

^'I< '98'. CONTROL

B--£J--fJ , 9£$/.

400

lBs

*--.--.

^1982. ²⁰⁰ ^lBS

2 YEAR BASAL AREA INCREMENT

GeOGRAPHICAL ReGION~ceN ^WASHINGTON

---*

- - #

18

-4,

"IT-r"l-r-.,..,. ,. r,·r""r"r r r" _

, , , , T ,-..-, "-'-"'-,,_""-"-r-,.". ,."_'-' -".. ,-,.,_, ...-, , _,_...-,.,-

75 I 00 , 25 , S0 I 75 200 22S

INITIAL BASAL AReA (SQ FT)

B A I

LEGEND: YEAR_TRT

-

(26)

) :; }) :) ) ) -; ) .] 3 ^j

18

16

14

12 B A I

1ta

8

6---..-

4

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=NE OREGON

~ = ~ = - ..

• * *

ale

r-r'-rT-TI"~-rl-r,. r T T ' " "'-TTr'.,.·'·l·.-r-T.,....TTr~TI·T-'-rTl'-TrT.,·r-l-r" .,-,-• • • • • • • I

75

10ta .125 150 176 200

225

INITIAL BASAL AREA (sa ^FT)

LEGEND: YEAR TRT * •• ¹⁹⁸¹

^J

^CONTROL

^~ ^$ ^~ ^t98t~

^{200 LBS}

IV

a-e-a 1981

J

400 LBS

^c; ^Q ^II t982~

CONTROL

^~

* •. *

¹⁹⁸²^J ^{200 LBS}

^{)( )( )(}

^1982~

^{400 LBS}

(27)

") ) ") ) ;) ) ) ) ) ') }

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=CENTRAL IDAHO

16

1

¹

16

14 _-K

)(

:: ..

~

--- ^..

8

6

--e--

A.~^{_ _}

---_Q.o---= •

^III

^*

---

(28)

) ) ⁾ ⁱ⁾ j j :; ) ) }) }

18

16

14

~

¹²

1

I

101

8

6

4

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL REGION=MONTANA

- _--= ~ ;; ;;;; :: ^:=I

=it:

;<;?"-

~-

^-

. . . - Q Q Q _.--~

r~r·fO-T,-rrrT r-r-r"T-rrr-J-rT,,-r Of I I I

,-r-r-t.,-r'-'-rr

^{I I} ^I

'-T--r-T",.-.-'

I I I I I I I J

75

100 125 150 175 20121

225

INITIAL BASAL AREA (sa ^FT)

LEGEND: YEAR_TRT

.-~-.

1981

J

CONTROL

~ & & 1981 1

2121121 LBS

I\)

e 8 8 1981 J

412J12J LBS

^-c- ^Q ^•

1982 .. CONTROL

^0'\

* • * 1982.. 20121 LBS )( )( )( 1982.. 4121121 LBS

(29)

) ) ;) ⁾ j) }) ) ) 1 ⁾ ^j

2 YEAR BASAL AREA INCREMENT

GEOGRAPHICAL

REGION=NORTH

IDAHO

6 8 16

~

...

.. ...

14

12 18

B

A

I 1~~

4 r...r-T·r'·' ..."-r'-Y,l-r.,-r-y--r.-rr,--r-' '-T-r-TTr-r"'rrT"T ...rT' ' r 'I'r'-'-T-'-rr"'-'-' ^{i i i ,} I

75 ^1f2Jf2J ¹²⁵ t5~ 176 200 225

INITIAL BASAL AREA (sa FT)

LEGEND:

YEAR_TRT . . - . - . 1981 " CONTROL ~ ~ ~ 1981 _~ 200 LBS _N

8 8 8 I 981 " 4~ra

LBS

^Q ^Q ^ca 1982"

CONTROL

^-..J

... -- 1982" 200 LBS )( )(~ 1962" 400 LBS

(30)

28

Jim Moore

Department of Forest Resources University of Idaho

Predictive Model of Response to Nitrogen Fertilization

~ Contrast with design model

=

differences between installations rather than within installations.

Predictive model R2 ₌ _.70 vs. R2 ₌ _.90 for the Design Models.

Variables in the predictive model that account for underlying

~ differences in growth between installations but do not interact with treatment are:

*S01l Depth - deep soils (>24") grow better than medium (12 to 24 " ) grow better than shallow soils (~12").

*Ash Depth - (where present) deep better than shallow ash illustrated later.

ash soils (>12") grow caps. This will be

of Figures illustrates the relationships growth response and initial basal area by

Figure 4.

*Douglas-fir site index (Monserud 1984) as site index increases growth increases. See Figure 1.

*Slope and aspect this is expressed as an interaction term (Stage 1976) in the model. The highest basal area increment occurs on Southerly aspects (other factors being equal). Similar results from other studies in Northern Hemisphere. See Figure 2.

*Soil parent material and initial stand density (basal area) - also influence the underlying differences in basal area growth rate between installations.

But more importantly they significantly interact with treatment. They both are important in predicting treatment response.

The next series between treatment parent material.

Figure 3. A bar graph showing differences in relative (%) response to treatment by parent materials.

Note: No response for valley fills and very large % response for sandstone.

The effect of initial basal area on relative response for Ash/Metasediments.

Notes: (1) This parent material is confined to North Idaho.

(31)

29

(2) (3) (4)

Relative response is highest at low densities.

The 400 lb. treatment is significantly more than the 200 lb. treatment.

Thi 30% response line. For2200 Ibs.

=

¹¹⁷

Ft lAc.; for 400 Ibs.

=

204 Ft lAc.

Figure 5. The effect of initial basal area on relative response for basalts.

the

Notes: (1)

(2)

Relative response is highest at low stand densities.

There is no significant difference between 200 and 400 lb. treatments.

Figure 6. The effect of initial basal area on relative response for granite.

(1) (2)

Notes: Relative response is highest at low stand density.

There is no significant difference between the 200 and 400 lb. treatments.

Figure 7. The effect of initial basal area on relative response for Valley fill.

Notes: (1) This parent material was sampled only in Montana.

(2) There was no treatment response on this parent material.

Figure 8. The effect of initial basal area on relative response for colluvium.

...,

(3)

(1) (2)

Notes: This parent material was sampled only in Montana.

There was a significant difference between the 200 and 400 lb. treatments.

There was a very high % response on this parent material, but this may not translate to as much absolute basal area response depending on the level of untreated growth.

This will be illustrated in SUbsequent figures.

Figure 9. The effect of initial basal area on absolute basal area increment for ash/metasediments with shallow ash (~12U).

Notes: (1) Control 2-year basa~ area increment peaks at approximately 130 Ft lAc.

(2) Absolute basal area response for the 200 lb.

treatment is highest at the lowest stand

(32)

30

densities, but the curve is relatively flat over the range of densities sampled.

(3) Absolute response f0

2

^the ⁴⁰⁰ lb. treatment peaks at about 120 Ft AC., although resionse is predicted to be greater than 4 _F~ /Ac.

even at an initial basal area of 175 Ft . (4) Ash/metasediment soils were sampled only in

North Idaho.

Fiqure 10. The effect of initial basal area on absolute basal area increment for ash/metasediments with deep ash

(~121')•

Notes: (1) The contrast of this fiqure with fiqure 9 illustrates the effect of having a deep ash cap on the site. There is an increase in the amount of absolute response to treatment due to the higher baseline (normal) growth on deep ash soils.

Fiqure 11. The effect of initial basal area on absolute basal area increment for ash/loess with a deep ash

(~12")• (1)

(2) (3)

Notes: Control (untreated) gro~h peaks at an initial basal area of 200 Ft /Ac.

Treatment response peaks at about 170 Ft2/AC.

There is no significant difference between the 200 and 400 lb. treatments.

Fiqure 12. The effect of initial basal area on absolute basal area increment for glacial t i l l with deep ash.

Notes: (1)

(2) (3) (4)

co~trol (untreated) qrowth peaks at about 160 Ft /Ac. initial basal area.

Response to the 200 lb. treatment is h~qhest

at the lowest initial basal area (75 Ft lAc).

Absolute response to thi 400 lb. treatment is largest at about 100 Ft initial basal area.

The response curves are relatively flat over the range of basal areas sampled on this parent material.

Fiqure 13. The effect of initial basal area on absolute basal area increment for granite.

Notes: (1)

(2)

Control growth is greates~ at an initial basal area of about 160 Ft for this parent material.

Absolute basal area response to the 200 lb.

treatment is qriatest at the lowest initial basal area (75 Ft lAc.).

(33)

31

(3) Response to the 400 lb. treatment peaks at an

in~tial basal area of approximately 125

Ft lAc.

(4) The response curves are relatively flat over the range of basal areas sampled. Similar to the pattern shown for glacial tills.

Figure 14. The effect of initial basal area on absolute basal area increment for colluvium.

Notes: (1) Because of the very slow normal (untreated) growth on this parent material, the "huge"

percent response (shown in Figure 8) translates to only a "large" absolute response.

(2) A relatively narrow range of initial basal area was sample2 on this parent material

( 105 to 175 Ft lAC.) and the curves do not extrapolate well outside of this basal area range.

(3) This parent material was sampled only in Montana.

Figure 15. The effect of initial basal area on absolute basal - area increment for alluvium.

Notes: (1) Control (untreated) growth pe2ks at an initial basal area of about 170 Ft lAc.

(2) Absolute basal area response to the 200 lb.

treatment is greatest

2at an initial basal of approximately 160 Ft lAc. for both nitrogen treatments.

(3) The response to the 400 lb. treatment is less than for the 200 lb. treatment on this parent material. SUbsequently, we discovered that the plots for the 400 lb. treatments had higher pre-treatment nitrogen mineralization rates (Min-N) than the 200 lb. treatment plots. When we statistically adjust for the differences in pre-treatment Min-N, the response to 400 lbs. becomes slightly higher than for the 200 lbs. treatment.

(34)

) ⁾ ~ ) ") ⁾ ~J j y J ⁾

2 YEAR BASAL AREA INCREMENT

GLACIAL

TILL~

12- OR LESS

ASH~

AVERAGE SOIL DEPTH

8Aa150~ SLOPEa2S~

ASPECTal80

• • • I • • • • • I ~""'-"T.

. . . .

I • • • • • • • • • I • • • • • • e I • I • , • • • • • • • I

SITE INDEX (FEET AT 50 YEARS) B

A I

49 60 60 70

80

90

100

w

t\)

Eigure 1. The relationship between untreated two-year basal area increment per acre and Douglas-fir site index.

(35)

;> ⁾ ⁾ ;; j) ) .J j ^} .>

,

2 YEAR BASAL AREA INCREMENT

GLACIAL

TILL~ 12-

OR LESS

ASH~

AVERAGE SOIL DEPTH

BA=t60~

SITE INDEX=70

B A I

10.0 9.8

• • • • I • • • • • • • • • I • .,T. • • • • I • • • • • • • • • I

9 4S 99 ISS t89 22S ^279' SIS ³⁶⁹

ASPECT (DEGREES) LEGEND- SLOPE

• • • 19 "

• • • 49 "

• • • 20 "

At Ia At S0 "

a a a

^{30 "}

w: w:

^Nt

60 "

^w^w

Figure 2. The relationship between untreated two-year basal area increment per acre and slope and aspect.

(36)

BAI INCREASE OVER CONTROL (%)

BY TREATHENT AND PARENT HATERIAL .

.:;. _{• J} ^.3 ;; ^j ^j ^J J' ⁾ ⁾ ^:»

RESPOOSE 188

Fie

8 I I ' "

"1'

^{" I I} ^{. .}

-58

2 .. 2 .. 2 .. 2 .. 2 • 2 .. 2 • 2 4 2 ..

e

8 8

e

⁸

e e

⁸ ^{8 8}

e

⁸ ⁸

e e e e

⁸ ^TRTHENT

8 8 8 8 ^(I 8 8 8 ^(I 8 8 8 8 8 8 8 8 8

G

A

^IS ^T

A F

C

A ^S

R ^S A

I

S

I 0 L

A

H

S

L

H

L L L N

N

I

A

L / L L U 0 P_HATER

L

H U V

T ^V

w

Figure 3. Two-year relative basal area response by soil parent material. ^~

(37)

) ) , ) ;) p iJ ^~ ⁾ ^; ^;) ^J

BAI INCREASE DUE TO FERTILIZATION

PARENT MATERIAL-ASH/METASEDIHENT

P

E R

C E

N T

o

F

I

75 lea

¹²⁵ ¹⁵⁹ ¹⁷⁵ ^28a

225 INITIAL BASAL AREA (SO FT)

LEGEND. TRTHENT • • • CONTROL

^~ ^{A •}

298 LBS o

^{II []}

-489 LBS

wU1

Figure 4. The effect of initial basal area on relative response for Ash/Metasediments.

(38)

) ^{, j} ⁾ ^;) ) _J!J ⁾ J ^j ^{. )} ⁾

SAl INCREASE DUE TO FERTILIZATION

PARENT HATERIALaBASALT

c o

N

T R

O . ^{I .} I

L

~

^I ^,

-10 ⁱ ^{• i} ^{• •} ⁱ ^• ⁱ ^• ^• ••••••••• 1•••••••••••••••• 1•••••••••••••••••••••••••

o

F

P E _

R 79 C

E N

T

75 190 125 158 175 290 225

INITIAL BASAL AREA

(Sa

FlY

LEGEND. JRTHENT • • • CONTROL

~ A A 299 LBS ^[I 9 B 499 LBS Yigure 5. The effect of initial basal area on relative response for Basalt.

W 0\

(39)

) :J _i"'-I j ) 21 ^.) w ^;) ^') ^J

BAI INCREASE DUE TO FERTILIZATION

PARENT MATERIAL-GRANITE

o

f

3_ I

C I

~

^I

T 19 I I

R I

o

^{J . .} ^.. ^tit ^{I •} ^• ^•

L

^I

I

-19 I

P E

R

C

E

N

T

15 109

125

159 175 299 225

INITIAL BASAL AREA (sa FT)

LEGEND- TRTHENT

^.. ^.. ^lit

CONTROL

^.. ^{A A}

299 LBS

^[] ^[J ^Il

400 LBS

Figure 6. The effect of initial basal area on relative response for granite.

w~

(40)

; ^;) ^)J ^} ^{. )} ¹¹ ⁱ⁾ ¹¹ ⁾ ^;>

}

BAI INCREASE DUE TO FERTILIZATION

PARENT MATERIAL-VALLEY FILL

.p E

R

C

E N T

o F

o

C N

T 1

R o

L

10 ••••••••• ' ••

'1.'

... Ii • • • • • i i i i I • • • • • • • • 1 • • • • • • • ' • • • • 1 • • • • • • • • • • • •

75

199 125 159 175 290 225

INITIAL BASAL AREA (Sa FT)

LEGEND- TRTHENT

^{III •} ^III

CONTROL

^{~ ~ ~} ^{299 LBS} ^{D [) D} ^{499 LBS}

w

00

Yigure 7. The effect of initial basal area on relative response for valley fill.

(41)

) ^;) ^)J j J ^j ^;) ^j :; .> ^j)

BAI INCREASE DUE TO FERTILIZATION

PARENT MATERIAL-COLLUVIUM

o F

C

o

N

T I

R

o

L ...¹U " . i i i • • • • • •^{f t} i • i • i i • • • • • • • • • • • • • • • • • • • • • "

P E

R C E

N T

75 10a 125 168 176 299 225

INITIAL BASAL AREA (SO FT)

LEGt:ND. TRTHENT .. • • CONTROL

^{.. A A} ^{299 LBS} ⁹ ^g ^B ^{499 LBS}

W

\0

Vigure 8. The effect of initial basal area on relative response for colluvium.

(42)

; J ⁾^... ) ;) J )J } j 11 ~

-- ^"

2 YEAR BASAL AREA INCREMENT·

PARENT MATERIAL-ASH/METASEDIMENT ASH CAP DEPTH=12- OR LESS 22

28 18

B 12

1 . . .

^~

A . •

I ^to ^•

76 tee

t25 t60 176

2ee

225

INITIAL BASAL AREA (sa FT)

LEGEND. TRTMENT .. .. .. CONTROL • • • 2ga LBS

B B B

4ga LBS

~o

~Figure 9. The effect of initial basal area on absolute basal area increment for ash/

metasediments with shallow ash (~l2n).

(43)

) ^-} ;; J ⁾ ^:a ⁾ ^;) .1 ^), t

2 YEAR BASAL AREA INCREMENT

PARENT HATERIALaASH/HETASEDIMENT ASH CAP DEPTH=HORE THAN 12-

22 29

B

A

J:

76 100 125 160 176 .' 200 225

INITIAL BASAL AREA (sa FT)

LEGEND

^I

TRTHENT • • • CONTROL

^• ^{e •} 290

LBS

^B ^{B B} 400

LBS

oI:lo f-4

Figure 10. The effect of initial basal area on absolute basal area increment for ash/metasediments with deep ash (>12").

(44)

j ;; figure 11. JThe effect of i'tltlol basot ord} on absolute bLtal or.o Increa..Jt for osh/loeS8 l.fth deeposh (,.2¹¹^{) .}

2 YEAR BASAL AREA INCREMENT

PARENT HATERIALaASH/LOESS ASH CAP DEPTH=MORE THAN 12-

J; y

76 199 0125

169 176 ^o.

290 225

INITIAL BASAL AREA (SO

^FT)

LEGEND

^I

TRTHENT ... • CONTROL

^• ^• ^{• 290}

LBS

^{Il B} ^B -490

LBS

os:.

to.)

Figure 11. The effect of initial basal area.on absolute basal area increment for ash/

loess with deep ash (>12").

(45)

) ::i ⁾ ~ J J ⁾ ^j ⁾ ~ ^":\.^~

2 YEAR BASAL AREA INCREMENT

PARENT MATERIAL-GLACIAL TILL ASH CAP DEPTH=MORE THAN

^12-

76 t99

125

169 176 ". 299

225

INITIAL BASAL AREA (SO FT)

LEGEND. TRTHENT .. .. .. CONTROL

^• ^A ^A ^2ra9

LBS

^Il ^{B B} -49a

LBS

.a:.w

Figure 12. The effect of initial basal area on absolute basal area increment fo~

glacial till with deep ash.

(46)

;; ^j ⁾ _:J ⁾ ^.} ⁾ ⁾ ⁾ ^~ J

2 YEAR BASAL AREA INCREMENT

PARENT MATERIAL-GRANITE ASH CAP DEPTH=12- OR LESS

76 100 126

159 175

200

225

INITIAL BASAL AREA (sa FT)

~i9ure 13. The effect of initial basal area on absolute basal area increment for granite.

LEGEND

a

TRTMENT • • • CONTROL

• e e

2sa LBS

^{B B B}

-4aa LBS

~

(47)

) j ) J ^;) J ⁾ ^j ⁾ ^} ^}

2 YEAR BASAL AREA INCREMENT

PARENT MATERIALaCOLLUVIUH ASH CAP DEPTH=12- OR LESS

29

76

IB8 125 IS0

176 . 208

225

INITIAL BASAL AREA (SO FT)

Fiqure 14. The effect of initial basal area on absolute basal area increment f0r colluvium.

LEGEND

^I

TRTHENT

ÎII ÎII ÎII

CONTROL

• • • 209

LBS

B B B -409

LBS

~

U1

(48)

) j ⁾ .ll ;; ⁾ ⁾ J J 3' ⁾

22 28

2 YEAR BASAL AREA INCREMENT

PARENT HATERIALaALLUVIUM ASH CAP DEPTH=12- OR LESS

I. i i i i i i i , , i i i i , , • • • i i ' i i ' • • , • • • • • • • , • , , • , , " • • • • • • I • • • • • • • • • I

76

t00 t25 15e 176

.. 299

225

INITIAL BASAL AREA (sa FT)

Figure 15. The effect of initial basal area on absolute basal area increment for alluvium.

LEGEND- TRTHENT • • • CONTROL • • • 2ae LBS

^{B B B}

480 LBS

.e:..

0'\

(49)

47

Summary

What have we gained in a practical sense from the information just presented? One way to illustrate the gains from the new information is to go through the following scenarios:

If we had applied 200 lbs. of nitrogen per acre to all the managed Douglas-fir stands in the Intermountain region as represented by our installations, we would have obtained

th~ overall average 2-year basal area response of 2.4 Ft lAc. or an average 31% increase in basal area growth.

These numbers are probably higher than we expected at the beginning of the project. But if these are th$ averages, think what response we must be getting on the best responders!

Table 1 illustrates how we can use the predictive models to eliminate the non-responders and concentrate the treatments on the better responding sites. Each contrast represents conditions that are common in each region (not the best or worst). The comparisons were selected to show the effects of parent materials and stand density on response in a useable way.

These differences will determine the profitability of an operational fertilization program if they continue in the same manner over time.

The evidence to date certainly indicates that nitrogen fertilization should be strongly considered as a viable silvicultural treatment on many sites in the Intermountain West. The key is to identify the best responding sites and concentrate on those that produce the highest return on the investment. We have come a long way toward identifying those sites in the last several years.

(50)

Table 1. Predicted response to 200 pounds of nitrogen per acre for various site and stand conditions in each geographi.c region.

Nutrition at

Nur·1BER OF INSTALLATIONS

YEAR OF INSTALLMENT

REGION 1 1981 1982 TOTAL

NORTHERN IDAHO S 14 19

CENTRAL IDAHO 3 S 13

MONTANA 8 8 16

NE OREGON 6 2 3

CENTRAL WASHINGTON 9 9 ·18

NE WASHINGTON 9 7 16

"'" TOTAL lIS LJS 90

DESIGN NODEl 1

(BAD

F ( YEAR , REGION , YEAR X REGION, INSTAllATION ( YEAR REGION )

BLOCK ( YEAR REGION INSTAllATION ) TREATMENT

REGION X TREATMENT

BA X TREATMENT BA2 X TREATMENT

BA X YEAR BA2 X YEAR )

R2

0.9025 f1SE = 0.0243 cv -

. 86

2 YEAR BASAL AREA INCREMENT

BY TREATMENT AND REGION BAI

o

II - I

I : J.lJ__ I

a

a

T T

T T T T TRTMENT

MEAN N 1D MONT C 1D NE OR C UA NE UA REGION

SAl INCREASE OVER CONTROL

BY TREATMENT AND REGION RESPONSE

TRTMENT

o

o

o

o

o

o

o

o

o

o

o

o

o

j

I :

~lJ t.. l

MEAN N 1D MONT C 1D NE OR C UA NE UA REGION

....

2 YEAR BASAL AREA INCREMENT

G£OGRAPHICAl R£GIONbC£NTRAl IDAHO

~ 1

lBs

~

CONTROL

~

lBs

las

*-*-.

las

1-~

~-'-"

~

"T""T-'-'-'-'-'-'~T-r-.-.-,..

0a

sa ,

INITIAL BASAL AR£A (SO FT) LEGEND:

,.

• •

2 YEAR BASAL AREA INCRtMENT

GE:OGRAPHICAL RE:GION:ONORTH IDAHO

e

2ee

~

8', 2ee LBS

~

CONTROL

"'" ^TOTAL ^lIS ^LJS 90

0.9025 f1SE = ^0.0243 cv -

. ⁸⁶

I : _{J.lJ__} I

T T T T ^TRTMENT

~lJ t.. ^l

MEAN N 1D ^MONT C 1D NE OR C UA NE UA REGION

~ ¹

^lBs

^CONTROL

^lBs

--.

^{8', 2ee} ^LBS

^CONTROL

'-,.

^Las

^CONTROL

^Las.

^..---==