Center for Sustaining Agriculture and Natural Resources
Washington State University, Wenatchee, WA

Individual results of all 1997 On-Farm Compost Trials
Brownfield replant
Cook topdress
Goehry new planting
Goehry topdress
Goehry interplant
Goehry compost in the planting hole new planting
Stevens replant
Sullivan new planting
VanWinkle topdress
VanWinkle replant
Wenatchee Valley College replant
95 ZurHausen replant
96 ZurHausen replant

Links to other sites
Summary of 1997 On-Farm Compost Trials
The Compost Connection publication


1997 Report : 1996 Brownfield Replant - Gala

Objective

To compare the effect of different composts and different application rates on tree growth and productivity.

Treatments                              

                                              Lincoln Cow Feedlot compost                  Lincoln Chicken compost

                                                       (total N = 1.9%)                                           (total N = 3.8%)                                                            1) 2.3 tons/A                                              4) 3.3 tons/A                                                            2) 3.1 tons/A                                              5) 5.0 tons/A                                                            3) 5.4 tons/A                                              6) 7.7 tons/A

All rates are on a treated area basis, and reported as wet weight.

Comments

Composts were surface-applied after the trees were planted in spring 1996. The soil was fumigated prior to planting. The experimental design is a randomized complete block, with 4 replications. Each plot consists of two adjacent rows approx. 100' in length. The orchard is managed organically. Alfalfa is grown as a covercrop between rows, and all trees are mulched with alfalfa after each mowing.

Data

10 tree trunk diameters per plot were measured on 9/25/97.

% Increase TCSA

2 year

Treatment

Year 1

Year 2

Cumulative

Lincoln Cow Feedlot, 2.3 Tons/A

42.5

100.0

185.8

Lincoln Cow Feedlot, 3.1 Tons/A

40.4

87.8

164.1

Lincoln Cow Feedlot, 5.4 Tons/A

43.1

94.2

178.9

Lincoln Chicken, 3.3 Tons/A

43.1

101.8

188.8

Lincoln Chicken, 5.0 Tons/A

44.2

93.2

178.2

Lincoln Chicken, 7.7 Tons/A

47.2

97.6

203.0

Source of Variation

P-value

P-value

P-value

Trt

0.877

0.612

0.364

Rep

0.392

0.003

0.009

P-values < .05 are considered significant.

Conclusions

Both compost rate and type have not appreciably influenced tree growth in the first 2 years. There are no significant differences among treatments. Tree growth was less than desirable in 1996, but was very good in 1997.

 

1997 Report : 1996 Cook Compost Topdress - Fuji

Objective

To determine how much compost is needed to optimize tree growth and fruit production on organically managed Fujis.

Treatments

4 rates of Nielsen chicken compost (3% N) were applied in spring 1996:

    0 scoops (check); 1 scoop per tree (5-6 lb); 2 scoops per tree (10-12 lb);  4 scoops per tree (20-24 lb)

Greensand at 300 lbs/A was applied to all trees in 1997.

Comments

The experimental design is a randomized complete block with 4 replications, with each row as a replication containing all treatments. A plot consists of 5 adjacent trees in a row. Leaf samples were taken for nitrogen analysis, SPAD leaf readings were taken, trunk diameters were measured on 10/27/97, crop load was estimated, and a 20-fruit sample was weighed and measured for diameter for each plot.

Data

Treatment

SPAD

Leaf N

% trunk

Yield

Frt. diam

Yield Efficiency

(scoops of compost)

(%)

growth

(# frt/tree)

(cm)

Kg frt/x-area

0

42

2.5

31.0

48.3

84

0.74

1

44

2.6

29.0

46.0

84

0.68

2

44

2.5

25.8

53.7

85

0.89

4

45

2.6

23.6

64.8

85

0.88

Source of Variation

P-value

P-value

P-value

P-value

P-value

P-value

Trt

0.230

0.896

0.217

0.412

0.886

0.412

Rep

0.911

0.861

0.130

0.607

0.598

0.521

P-values < .05 are considered significant.

Conclusions

Tree performance appears to be most influenced by soil changes within the orchard. No significant treatment differences were measured. However, trees in several check plots appeared to have a lower leaf density and fruit appeared more mature than on the compost treated plots. The inverse relationship between trunk growth and yield is normal. Leaf N levels are in the sufficient range.

  

1997 Report : 1996 Goehry New Planting - Cameo

Objective

To determine the effect of compost applied to apple trees on previously unfarmed ground.

Treatments

0,10, and 20 tons/A of Cedar Grove yard waste compost ( 0.9% total N) were applied prior to planting in spring 1996. Rates were on a treated area basis. Compost was spread in a 6' band over the planting row and incorporated.

Cedar Grove compost was reapplied in 1997, with trees in the 10 Ton plot getting 1 scoop, 20 Ton plot getting 2 scoops, checks getting none.

Comments

A modified randomized complete block design was used with 4 replications. Each row was a replication of all 3 treatments, with the check between the two rates. Reps 1 & 2 of all treatments were mulched in 1996 with alfalfa flakes. Tree trunk diameters were measured on 10/23/97.

Data

Year 1

Year 2

Cumulative

%

% trunk

% trunk

% trunk

Treatment/Rep

Leaf N

growth

growth

Growth

Check

2.7

99.0

96.4

294.7

10 T/A Cedar Grove

2.6

99.4

102.0

299.8

20 T/A Cedar Grove

2.5

106.3

97.7

314.9

rep 1

109.5

rep 2

114.6

rep 3

86.0

rep 4

84.7

Source of Variation

P-value

P-value

P-value

P-value

Trt

0.415

0.882

0.319

0.824

Rep

0.601

0.328

0.0005

0.051

P-values <.05 are considered significant.

Conclusions

Trunk growth was excellent in both years. The rep effect in year 2 is dramatic. One possible explanation is that reps 1 & 2 were given a mulch of alfalfa flakes during their first leaf. Otherwise there is no treatment effect due to compost. All trees had adequate leaf N.

  

1997 Report : 1996-97 Goehry Compost Topdress - Fuji

Objective

To compare the effect of different composts upon poorly growing apple trees.

Treatments

In spring 1996 Sunland chicken compost, Cedar Grove yard waste compost, and Stutzman chicken compost were applied by shovel scoop to the ground surrounding the tree trunks of approx. 550 trees. Rates were 0, 1, or 2 scoops/tree. In spring 1997 composts were re-applied at the same rates, however BION dairy compost replaced Sunland chicken.

Comments

Entire rows of approx. 40 trees constitute one replication, except for the checks and Stutzman. Checks are made up of 5 trees at alternating row ends. Stutzman was applied to only a few trees within one row. There are 2 to 4 reps of the other treatments. Leaf samples were taken for nitrogen analysis, SPAD leaf readings were taken, trunk diameters were measured on 11/25/97, and a 40-fruit sample was weighed and measured for diameter for each plot. No tree yield could be calculated due to the amount of fruit blown off trees by wind.

Data

% trunk

(lb.)

(cm)

Treatment

Growth

Leaf N

SPAD

Frt. Wt.

Frt. Diam

North end check

14.9

2.4

43

0.64

86

South end check

15.0

2.3

41

0.65

87

BION, 2 - 2 1/2 Gal.

15.7

2.4

42

0.64

86

BION, 4 - 5 Gal.

17.2

2.5

42

0.65

87

Cedar Grove, 2 - 2 1/2 Gal

15.6

2.4

42

0.67

86

Cedar Grove, 4 - 5 Gal.

12.5

2.5

42

0.66

86

Stutzman, 2 - 2 1/2 Gal.

5.1

2.5

39

0.64

86

Stutzman, 4 - 5 Gal.

15.1

2.6

40

0.62

85

Source of Variation

P-value

Trt

0.257

Rep

0.262

P-values <.05 are considered significant.

Conclusions

No significant treatment differences were observed. The Stutzman treated trees performed poorly in both years, perhaps due to the high salt content of that compost.

  

1997 Report : 1997 Goehry Interplant - Gala

Objective

To compare the effect of different composts on tree growth and productivity.

Treatments

8 combinations of composts and soil amendments were mixed into augered planting holes.

Check                                                    5 gallons Cedar Grove compost
1 cup Leonardite                                  5 gal. BION + 1 cup Leonardite
5 gallons BION compost                     5 gal. Lincoln + 1 cup Leonardite
5 gallons Lincoln mix compost           5 gal. Cedar Grove + 1 cup Leonardite

Comments

Trees were interspersed within an existing Gala block. All 8 treatments were grouped within a row. Plots are single trees replicated 10 times. Tree trunk diameters were taken at planting time and on 9/30/97.

Data

% trunk

Treatment

growth

Check

26.8

Leonardite

26.8

Lincoln mix

22.4

Cedar Grove

23.5

BION

31.6

Lincoln mix + Leonardite

21.3

Cedar Grove + Leonardite

33.4

BION + Leonardite

25.8

Source of Variation

P-value

Trt

0.604

Rep

0.021

P-values < .05 are considered significant.

Conclusions

Trees did not respond to any soil amendments in the first year. All trunk growth was much less than desirable.

  

1997 Report : 1996 Goehry Compost-in-the-Planting Hole New Planting - Cameo

Objective

To determine the effect of compost directly incorporated into the planting hole.

Treatments

Check
Leonardite, 1 cup (a mined humic acid product)
Stutzman chicken compost, 2.5 gal
Stutzman chicken compost, 2.5 gal + 1 cup Leonardite
Stutzman chicken compost, 4.0 gal
Cedar Grove yard waste compost, 2.5 gal
Cedar Grove yard waste compost, 5.0 gal
Cedar Grove yard waste compost, 5.0 gal + 1 cup Leonardite
Cedar Grove yard waste compost, 5.0 gal + 2 cup Leonardite
Check with Aliette (a fungicidal root dip)
Check without Aliette
Total N: Stutzman - 4.8%; Cedar Grove - 0.9%
E.C.: Stutzman - 27 mmho/cm; Cedar Grove - 4 mmho/cm.

Comments

This site was previously unfarmed. Plots consist of 3 consecutive trees, mostly unreplicated. The Aliette treatments are located in an adjacent row, 2 trees/plot, replicated 3 times. This was intended more as an observational trial.

Data

Year 1

Year 2

Cumulative

% trunk

% trunk

% trunk

Treatment

growth

growth

growth

Check

57.5

60.6

152.4

Leonardite, 1 cup

86.3

112.2

294.1

Stutzman, 2.5 gal

38.1

107.4

187.5

Stutzman, 2.5 gal + leo, 1 cup

19.3

126.6

170.7

Stutzman, 4 gal

58.6

142.4

280.7

Cedar Grove, 2.5 gal

97.7

82.3

262.3

Cedar Grove, 5 gal

91.3

104.3

294.1

Cedar Grove, 5 gal + leo, 1 cup

114.0

106.2

333.5

Cedar Grove, 5 gal + leo, 2 cup

139.6

114.1

414.0

Aliette root dip

64.1

88.2

209.2

no root dip

96.2

107.5

307.3

Conclusions

The composts appear to be enhancing tree growth, however the sample sizes are too small to provide statistical confidence. There appears to be a growth-enhancing effect of the leonardite. The Stutzman compost may have reduced growth due to the high salt content in the first year. It is interesting that the check trees grew significantly poorer in both years, even though this is virgin ground. They grew considerably less than the check trees in the rest of the Cameo block. The Aliette root dip appeared to have no effect. Additional testing, given the promising results, is needed.

 

1997 Report : 1996 Stevens Replant - Gala

Objective

To compare different composts and different application rates on tree growth and productivity.

Treatments

Check (no compost)
Stutzman chicken 10 tons/ A          Lincoln chicken 15 tons/ A
Stutzman chicken 20 tons/ A          Lincoln chicken 30 tons/ A
Stutzman chicken 30 tons/ A          Lincoln chicken 45 tons/ A

Rates are on a treated area basis. Leonardite @ 40 lb/ A was applied to all but 3 rows.

Comments

Composts were applied prior to tree planting and then incorporated. A randomized complete block design was used, with 5 replications. Trunk diameters were measured 9-22-97. Top leader growth was measured 10-2-97.

Data

Table 1 - with Leonardite

Year 1

Year 2

Cumulative

Top

Replicated

% trunk

% trunk

% trunk

Leader

Treatments

growth

growth

growth

Leaf N

Growth (cm)

Check

45.9

77.1

123.0

2.4

19

Stutzman 10T/A

47.0

81.8

128.8

2.6

24

Stutzman 20T/A

41.5

79.1

120.6

2.5

23

Lincoln 15T/A

41.6

78.4

120.0

2.5

23

Lincoln 30T/A

40.8

89.5

130.3

2.5

24

Source of Variation

P-value

P-value

P-value

P-value

P-value

Trt

0.734

0.667

0.908

0.497

0.333

Rep

0.720

0.331

0.672

0.022

0.942

P-values <.05 are considered significant.

Table 2 - with Leonardite

Year 1

Year 2

Cumulative

Top

Unreplicated

% trunk

% trunk

% trunk

Leader

Treatments

growth

growth

growth

Leaf N

Growth (cm)

Stutzman 30T/A

28.5

102.9

131.4

2.6

23

Lincoln 45T/A

7.4

50.7

58.1

2.4

16

 

Table 3 - without Leonardite

Year 1

Year 2

Cumulative

Top

Unreplicated

% trunk

% trunk

% trunk

Leader

Treatments

growth

growth

growth

Leaf N

Growth (cm)

Check

34.8

74.8

109.6

2.6

21

Stutzman 20T/A

29.9

77.6

107.6

2.6

21

Stutzman 30T/A

23.9

40.0

63.9

2.6

11

Lincoln 30T/A

32.3

91.4

123.8

2.7

23

Lincoln 45T/A

30.9

108.6

139.5

2.7

23

 

Table 4

Year 1

Year 2

Top

% trunk

% trunk

Leader

growth

growth

Leaf N

Growth (cm)

Trts. with Leonardite

42.8

81.9

2.5

22

Trts. w/out Leonardite

32.4

81.3

2.6

22

Table 4 includes data from Check, Stutzman 20T/A, & Lincoln 30T/A;
Leonardite trts. have 5 reps. Without Leonardite trts. have 2 reps.

Conclusions

Only in Year 1 % trunk increase did the Leonardite treatmented trees do better than those without Leonardite (Table 4). Differences between types of compost and rates have not had a significant effect upon tree growth to date (Table 1).All trees appear to have adequate N, but the leader growth seems less than desired. First year trunk growth is less than desirable.

 

1997 Report : 1996 Sullivan New Planting - Cameo and Fuji

Objective

To evaluate various organic amendments for growing high quality organic apples in Columbia Basin sand.

Treatments

A = K-mag, rock P, sulfur, bloodmeal: 1lb. minerals/tree
M = BION + ground-up carp: 5 gallons/tree
B = BION: 5 gallons/tree

Comments

Treatments were applied to whole rows and replicated 3 times, using a randomized complete block design. Three rows of Cameo and 6 rows of Fuji were treated.

All sampling was done on a group of 20 adjacent trees in a row, on the south end of the block. Alfalfa is grown between rows and is allowed to drape over the orchard rows as a living mulch. Trunk diameters and leader growth were measured on 10/5/97. Leaves were sampled for nitrogen analysis and SPAD readings in early July.

Data

avg lateral

Year 1

Year 2

Cumulative

7/3/97

leader

% trunk

% trunk

% trunk

Cameo

SPAD

Leaf N

(cm)

growth

growth

growth

A

46

2.6

59

45.5

97.0

188.2

M

48

2.8

81

77.8

120.8

296.0

B

49

2.9

82

85.4

122.3

307.2

Fuji

A

51

3.0

98

107.6

148.8

423.4

M

49

3.0

98

125.8

147.0

465.0

B

49

2.8

93

141.6

144.8

485.2

Combined

A

49

2.9

85

86.9

131.6

345.0

M

49

2.9

92

109.8

138.3

408.7

B

49

2.9

89

122.9

137.3

425.9

Source of Variation

P-value

P-value

P-value

P-value

P-value

P-value

Trt

0.998

0.916

0.695

0.005

0.701

0.055

Rep

0.278

0. 292

0.073

0.001

0.018

0.002

P-values <.05 are considered significant.

Conclusions

The trees at this site exhibited some of the highest trunk growth of all sites monitored, despite the extremely sandy soils. Trunk growth, leader growth, and leaf N were all lower in the Cameo trees compared to the Fuji trees. No significant treatment differences in tree growth were observed in the second year.

 

1997 Report : 1996 Van Winkle Desert Rose - Compost Topdress - Gala

Objective

To compare the effect of different amounts of compost and application methods on tree growth and fruit production of apple trees.

Treatments

A - Check - no compost
B - 5 gal ( 34 lb/ tree) Lincoln chicken compost surface-applied close to tree
C - 10 gal ( 68 lb/ tree) L. chicken compost surface-applied close to tree
D - 15 gal ( 102 lb/ tree) L. chicken compost surface-applied over weed strip
E - 15 gal ( 102 lb/ tree) L. chicken compost incorporated into weed strip
F - 20 gal (136 lb/ tree) L. chicken compost surface-applied over weed strip

Compost was applied by hand in the spring of 1996 to 5th leaf Imperial Gala on EMLA 26. No additional compost was applied in 1997.

Comments

The experimental design is a randomized complete block, with 3 replications. Each plot consists of 5 adjacent trees. Trunk growth was measured on 9-8-97 and compared with measurements from the previous year. Leaf samples were taken and analyzed for nitrogen content and SPAD leaf readings were also taken. Crop load was estimated, but no fruit measurements were taken.

Data

2 - year

1997

Cumulative

% trunk

% trunk

Yield

Treatment

growth

growth

SPAD

Leaf N

(# fruit/tree)

A

20.2

48.8

48

2.6

84.7

B

27.6

55.4

48

2.7

94.0

C

29.0

63.8

48

2.7

91.3

D

23.9

50.7

48

2.7

95.7

E

24.0

50.6

49

2.8

93.3

F

20.7

51.2

49

2.8

83.8

Source of Variation

P-value

P-value

P-value

P-value

P-value

Trt

0.027

0.069

0.149

0.110

0.920

Rep

0.063

0.076

0.812

0.863

0.548

P-values <.05 are considered significant.

Conclusions

Compost treatment did lead to some significant trunk growth differences in 1997. But none in 1996. However, there is no clear rate response, and thus it is difficult to interpret the results. All trees appeared to have adequate leaf N. Compost treatment had no influence on fruit yield or size in either year.

 

1997 Report : 1996 Van Winkle Replant - Fuji

Objective

To compare different composts and different application rates on tree growth and productivity.

Treatments

Control
Lincoln chicken compost @ 22 tons/ acre
Lincoln chicken compost @ 44 tons/ acre
Cedar Grove compost @ 10 tons/ acre
Cedar Grove compost @ 20 tons/ acre
Cedar Grove compost @ 30 tons/ acre
Cedar Grove compost @ 40 tons/ acre

Comments

Composts were applied and incorporated before planting. The field is split in two, north vs. south ends (representing 2 soils), with the center of the field untreated. A variety of Fuji strains were planted, which interfered with the experimental design. Three comparisons were salvaged, with trunk diameter measurements taken.

Data

1997

% trunk

Red Fuji Nagafu M9

Growth

L22 (north)

53.0

L44 (north)

65.3

Source of Variation

P-value

Trt

0.538

Rep

0.896

1997

1997

% trunk

% trunk

Red Fuji BC#2 Emla 26

Growth

Red Fuji BC#2 Emla 26

growth

N Check

87.9

S Check

82.0

CG20 (north)

98.8

CG20 (south)

99.0

CG30 (north)

109.7

CG30 (south)

93.1

CG40 (north)

90.1

L22 (south)

72.0

Source of Variation

P-value

Source of Variation

P-value

Trt

0.448

Trt

0.233

Rep

0.511

Rep

0.678

Conclusions

Due to the confounding by difference varieties, this study provides little insight. However, on the EMLA 26 trees, the measured trees all showed good trunk growth. The trees with Cedar Grove compost showed a trend of increased growth over the check trees.

 

1997 Report : Wenatchee Valley College 1997 Replant, Sunnyslope

Objective

To determine the effect of compost and root inoculants on apple trees planted on soil which has historically experienced severe replant problems, i.e. to attempt to find an alternative to fumigation.

Treatments

1 = No Compost; 2 Cups Rhizone
2 = 5 Gal Compost + 1 Cup Rhizone
3 = 5 Gal Compost + 2 Cups Rhizone
4 = 10 Gal Compost
5 = 10 Gal Compost + 1 Cup Rhizone
6 = 10 Gal Compost + 2 Cups Rhizone
8 = No Compost; Rhizone Root Dip
9 = 10 Gal Compost + Rhizone Root Dip

Rhizone is a microbial inoculant from Cascade Envirosystems.

Comments

Half of the block was fumigated, half was not. One row in each half was treated with combinations of yard waste compost incorporated into the planting hole, rhizone applied as a liquid to the planting zone, and/or rhizone applied as a root dip. Each plot (a treatment-rep) is 3 adjacent trees within the row, with all plots replicated at least 4 times.

Data

% trunk

% trunk

Fumigated

growth

Non-fumigated

growth

1

50.7

1

28.1

2

55.8

4

53.8

3

53.6

6

52.6

4

72.0

8

43.6

5

36.2

9

23.4

6

54.0

Source of Variation

P-value

Source of Variation

P-value

Trt

0.131

Trt

0.123

Rep

0.0001

Rep

0.304

P-values <.05 are considered significant.

Conclusions

Soil fumigation increased tree growth on the control plots from 28% to 51%. However, this is still far below optimal growth for a newly planted tree. The variability across the site was very high. There are no significant results after the first year. It is interesting to note that treatments 4 and 6 in the non-fumigated section had tree growth similar to treatments 3 and 4 in the fumigated section.

 

1997 Report : 1995 ZurHausen Replant - Red Delicious

Objective

To compare different types and rates of compost when applied to the planting hole; to improve tree growth and overcome potential replant problems.

Treatments

New Soil + 0 % Compost             Old Soil + 0 % Compost
New Soil + 5 % Compost             Old Soil + 5 % Compost
New Soil + 10 % Compost           Old Soil + 10 % Compost
New Soil + 20 % Compost           Old Soil + 20 % Compost
New Soil + 40 % Compost           Old Soil + 40 % Compost

Comments

Sunland chicken compost was mixed into the planting hole at planting; New soil came from a non-agricultural source; Old soil was that removed from the planting hole. Treatments were applied to single trees as plots: 10 trtmts x 4 reps = 40 trees. Trunk diameter measurements were taken 10/14/97 and compared to measurements taken previous years.

Data

Trunk Growth (% Increase TCSA)

                       3 year

Old soil only

Year 1

Year 2

Year 3

Cumulative

Old soil + 0% compost

49.2

107.7

39.5

342.1

Old soil + 5% compost

51.0

74.8

34.8

266.8

Old soil +10% compost

46.7

111.5

36.1

319.9

Old soil +20% compost

54.1

138.7

50.9

462.5

Old soil +40% compost

47.3

152.2

70.7

550.0

Source of Variation

P-value

P-value

P-value

P-value

Trt

0.963

0.123

0.487

0.277

Rep

0.306

0.354

0.230

0.440

New soil only
New soil + 0% compost

68.5

133.1

58.1

508.1

New soil + 5% compost

56.3

152.8

48.1

494.6

New soil +10% compost

79.7

140.0

53.4

560.4

New soil +20% compost

96.3

117.4

20.0

409.2

New soil +40% compost

102.2

134.5

54.6

609.7

Source of Variation

P-value

P-value

P-value

P-value

Trt

0.065

0.762

0.498

0.682

Rep

0.003

0.025

0.038

0.096

P-values <.05 are considered significant.

   3 year

ALL trt combined:

Year 1

Year 2

Year 3

Cumulative

Source of Variation

P-value

P-value

P-value

P-value

Trt

0.006

0.173

0.567

0.216

Rep

0.003

0.006

0.004

0.034

Conclusions

Third year results show no additional benefit to the trees by having new soil. The boost in year 1 was 40%, year 2 - 14%, year 3 - 0%. The initial benefit, however, is reflected in the greater cumulative % trunk growth with new soil.

The addition of compost to the planting hole was of benefit in year 1 to trees receiving new soil and in years 2 and 3 to trees with old soil-20% and old soil-40% compost added. The question, "Can the addition of compost to the planting hole give a benefit similar to the addition of new soil?" can tentatively be answered "Yes" at the 20% and 40% levels.

Soil variability between reps is dramatically influencing any treatment differences that may occur, especially in the new soil treatments. A larger-area study would help eliminate this problem.

  

1997 Report : 1996 ZurHausen Replant

Objective

To compare different types and rates of compost when applied to the planting hole; to improve tree growth and overcome potential replant problems.

Treatments

A = Check (no compost)
B = 10% (4.7 gal) of planting hole volume - Sunland chicken compost
C = 20 % (9.4 gal) of planting hole volume - Sunland chicken compost
D = 10% (4.7 gal) of planting hole volume - Cedar Grove yardwaste compost
E = 20 % (9.4 gal) of planting hole volume - Cedar Grove yardwaste compost
Biosolid = a Biosolid soil mix (100 % of planting hole volume)
Cedar Grove compost - 0.9% total N
Sunland compost - 1.1% total N

Comments

Composts were mixed into the planted hole at the time of planting. Compost treatments were applied to 3-tree plots, replicated 6 times. The Biosolid treatment was applied separately to a group of 6 trees. Trunk diameter measurements were taken 10-14-97 and compared to measurements taken the previous year.

Data

Trunk Growth ( % increase TCSA )

2 year

Treatment

Year 1

Year 2

Cumulative

A

111.3

121.6

368.8

B

113.8

133.3

400.1

C

97.4

136.3

367.1

D

124.7

145.0

450.2

E

111.4

138.0

403.1

Source of Variation

P-value

P-value

P-value

Trt

0.781

0.418

0.312

Rep

0.124

0.276

0.870

Biosolid

40.8

108.4

194.4

P-values <.05 are considered significant.

Conclusions

All trees grew very well, regardless of treatment, except for the Bios trees in 1996. Year 1 growth was considerably better than the growth in the 1995 study, except for the new soil plus high rate of compost. It will be interesting to see whether the % increase in trunk growth slows down in 1998, as it did in year 3 of the 1995 replant trial.