Transcript Orchard Floor Management David Granatstein WSU Center for Sustaining Agriculture and Natural Resources Wenatchee, WA.

Orchard Floor Management
David Granatstein
WSU Center for Sustaining Agriculture and
Natural Resources
Wenatchee, WA
Orchard Floor Management
Functions
Water intake/storage
Physical support
Gas exchange for roots
Nutrient cycling/storage
Habitat (micro, macro)
Micro-climate
Impacted by:
Understory species
Understory canopy
Irrigation system
Nutrient inputs
Spray drip
Organic inputs
Orchard Floor Management Review
Microclimate:
 soil temperature inverse to the amount of herbage or
mulch
 plant mulch dampens extremes of daily soil temperature
 plant cover reduces minimum air temperature by 0.5-1.0oC
 bare, compacted wet soil raised minimum air temperature
by as much as 2oC
 dwarf rootstocks grow best at 14oC vs. up to 27oC for
seedling rootstocks
(Skroch & Shribbs, 1986)
Orchard Floor Management Review
Soil quality:
 avoid cultivation
 favorable soil effects: legumes > grass > mulch > bare
ground > cultivation
Water:
 soil moisture availability mulch > bare soil > minimal
cultivation > grass > legumes >continuous cultivation
 mowing decreases water use
(Skroch & Shribbs, 1986)
SOIL
 Complex, dynamic living medium as
indispensable to plant growth as sunlight and
air.
 Civilizations have fallen throughout history
due to failure to maintain the quality of soils.
 Source and medium of delivery of most water
and nutrients for plants.
 Defined by its physical, chemical, and
biological properties..
SOIL QUALITY
Definition
“Capacity of a soil to function within ecosystem
boundaries
to:
 sustain biological productivity
 Maintain environmental quality
 promote plant and animal health.”
Not a soil property, but a value based on human
needs.
Soil health and quality are used interchangeably.
Soil Quality
Chemical
Biological
Physical
• Dynamic interplay of 3 aspects
• Short-term and long-term changes
• Influenced by environment (climate,
geology, plants)
• Influenced by human activity (erosion,
fertilization, irrigation, plants)
Soil Quality Reference Point
Current System
Native Ecosystem
Dryland wheat (KS)
Prairie
Rainfed corn (WI)
Temperate forest
Paddy rice (Asia)
Tropical rainforest
Irrigated potatoes (ID)
Shrub-steppe
Orchard (Yakima)
Shrub-steppe
Reference Point
Prairie
Pasture ?
??
Pasture ?
??
INDICATORS OF IMPROVED SOIL
QUALITY
Increasing:
Infiltration
Aggregate stability
Macropores
Aeration
Biological activity
Water-holding capacity
Soil organic matter
Decreasing:
Bulk density
Soil resistance
Runoff
Erosion
Nutrient losses
Diseases
Production costs
Carbon – the key ingredient
Carbon (C), the basis of Soil Organic
Matter, which affects:
Physical – bulk density, aggregate stability,
water-holding capacity
Chemical – cation exchange capacity,
nutrient release
Biological – energy source for microbes,
base of the soil food web, nutrient
turnover, soil-borne diseases
SOIL ORGANIC MATTER
Friends:
No-till
Mulching
Organic amendments
Cool temperatures
Nutrient balance
Enemies:
Tillage
Erosion
Fumigation
Herbicides, bare ground
Leaching, nutrient export
Carbon Budget
Inputs
Crop residues – leaves, roots, prunings
Green manures
Animal manures
Imported organics – compost, yard debris, etc.
Losses
Background soil respiration
Tillage – accelerated mineralization
Erosion – wind, water
Crop export – roots
Burning
Soil Quality Testing
Chemical
Biological
Physical
Integration
Soil Quality Index
Testing Approaches
Soil – physical, chemical, biological
Plant – bioassay
Ecosystem – watershed, energy, diversity
Soil Quality Index – Orchard Systems
Four soil functions (after Karlen et al., 1994):
 Accommodate water entry (weight 0.20)
 Facilitate water transfer and absorption (weight 0.20)
 Resist degradation (weight 0.20)
 Sustain fruit quality and productivity (weight 0.40)
(Glover et al., 1998)
Soil Quality Index
Function: Accommodate water entry
Indicator:
Infiltration
Aggregate stability
Surface bulk density
Earthworms
(Glover et al., 1998)
Weight
0.40
0.30
0.20
0.10
Soil Quality Index
Function: Facilitate water transfer and absorption
Indicator:
Water filled pore space
Porosity (0-15 cm)
Organic C (0-15 cm)
Earthworms
(Glover et al., 1998)
Weight
0.40
0.30
0.15
0.15
Soil Quality Index
Function: Resist degradation
Indicator:
Aggregate stability
Microbial processes
(Glover et al., 1998)
Weight
0.60
0.40
Soil Quality Index
Function: Sustain fruit quality and productivity
Indicator:
Rooting environment
Water relations
Nutrient relations
Chemical barriers
(Glover et al., 1998)
Weight
0.27
0.27
0.26
0.20
Soil Quality Index for 1998
WSU Orchard Systems Trial – Zillah, WA
Function
Water entry
Orchard System
Conventional
Integrated
0.09
0.14
Organic
0.17
Water transfer
0.17 b
0.19 a
0.17 b
Resist degrad.
0.14 b
0.20a
0.16 ab
Sustain product.
0.13 b
0.34 a
0.36 a
Total
0.71 b
0.87 a
0.86 a
(Glover et al., 1998)
WSU Orchard Systems Trial - Zillah, WA
Soil Organic Matter Content (0-15 cm)
Conventional
Organic
4.0
3.5
OM (%)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1994
1995
1996
1997
1998
Soil Biology
The last frontier ?
The ultimate black box ?
Microbe - Microbe
Microbe - Macrofauna
Microbe - Plant
Effect of Apple Replant Disease –
Gala/M26, Moxee, WA
Replant soil
‘Virgin’ soil
Growth of ‘Gala’ Apple Seedlings in Soil
from Orchard Blocks of Varying Age
Changes in Relative Recovery of Specific
Microorganisms with Increasing Age of
WVC Orchard Blocks
90
% of total isolates
80
70
60
50
40
30
20
10
0
NC
1 yr
2 yr
P. putida
3 yr
P.f.bv3
4 yr
R. solani
5 yr
Cover Crops and Fallow
No change in disease pressure with one-year
fallow
Wheat cover crops effective in reducing
Rhizoctonia, Pythium, Pratylenchus penetrans;
inducing microbial shifts; and enhancing tree
seedling growth
Effect of wheat is very cultivar-specific
Rapeseed cover crop moderately effective, but soil
amendment with rapeseed meal is promising
Growth of ‘Gala’ Apple Seedlings in CV
Orchard Replant Soil Following Planting
with Different Wheat Cultivars
Other Cultural Controls
Autumn trenching nearly as effective as soil
fumigation
Planting new tree rows in former drive aisles also
effective
Alternating between apple and non-susceptible
perennial crop (e.g. cherry)
Plant more resilient or vigorous rootstocks
Trench
Control
Recovery of Fungi from Apple Roots
at CV Orchard
% of root segments
25
20
15
10
5
0
R. solani
Pythium
Check
Phytophthora
Fumigated
Trench
Cylindrocarpon
Organic Amendments
Evaluating Compost Quality for
Orchard Use
What end use?
Absence of contaminants
Maturity
Moisture content
Organic matter
Electrical conductivity (EC)
pH
Total N
Available N
Nutrient Content of WA Composts
Parameter
Org. Matter (%)
Chicken (3) Cow (4)
Yard (3)
4-78
30-50
30-50
pH
6.3-8.3
6.1-8.9
6.3-7.6
E.C. (mmho/cm)
25-30
7-25
2-13
C:N
10-38
10-32
13-23
Total N (%)
1.1-4.2
0.9-1.9
0.8-2.0
NO3-N (ppm)
162-2460
36-2081
8-1421
NH4-N (ppm)
3600-9780
16-306
17-50
Total P (%)
0.9-1.8
0.2-0.8
0.2-0.3
Total K (%)
0.6-2.5
0.3-1.4
0.4-1.1
(Granatstein, 1996)
Comparison of Testing Labs
Mean
pH
E.C.
Range
C.V.
Chicken
6.6
5.7 – 7.7
10
Yard
6.9
6.5 – 7.3
5
Chicken
25
14 – 38
34
7
4 – 11
36
(mmho/cm) Yard
Total N
Chicken
3.6
2.9 – 4.2
12
(%)
Yard
1.2
0.9 – 1.4
16
NH4-N
Chicken
8620
6700 – 10500
19
(ppm)
Yard
370
17 - 1400
158
Low C.V. – pH, total N, total P, organic matter
Compost Costs
$/wet ton
FOB
Chicken manure 40
compost
Dairy manure
24
compost
Yard debris
14
compost
$/wet ton
Freight
30
$/dry ton
Delivered
107
$/lb N
dry
1.31
17
80
1.74
26
70
2.69
Nutrient $ Value of Compost
Chicken manure compost
(4% total N)
Yard debris compost
(2% total N)
Value $/wet ton
Total
Available
Nutrient
Nutrient
$41-53
$13-14
$20-23
$5
Includes N, P, K, Ca, S, Zn
(37¢lb N; 40-90¢/lb P; 21¢/lb K; 9¢/lb Ca; 11¢/lb S; $1.40/lb Zn)
Based on fertilizer prices of 2/98.
Organic N Sources and Costs
Source
%N
(dry)
Cost per
ton ($)
Cost per
lb N ($)
Chilean nitrate*
16
560
1.75
Bloodmeal
13
792
3.05
Feathermeal
12
690
2.87
Bio-Gro fish by-product
9
650
3.61
Canola meal
6
395
3.29
Chicken man. compost
4
80
1.33
Alfalfa meal
3
278
4.63
* Chilean nitrate is restricted by most organic programs.
Disease Suppression with Compost
• Need sufficient organic matter to support
microbial growth/activity
• General Suppression – occurs as compost
matures and limits readily available substrate;
effective on Pythium, Phytophthora
• Specific Suppression – requires colonization by
microbial antagonists of pathogen; needed for
Rhizoctonia
• Suppressive ability hard to predict in terms of
range and longevity of control; influenced by
compost feedstocks, production process
Effect of Compost on Trunk Growth
New orchard sites - 3 year cumulative
% increase in TCSA
1000
900
800
700
600
500
P = 0.04 R2 = 0.22
400
0
10
20
30
40
Compost Rate (lb/tree)
50
60
Foliar Disease Control with Compost
Tea – Oregon, 1996
Crop/Disease
No
Water
Compost
Best
Trt
Control
Tea
Fungicide
- - - - - - % infection or infestation - - - - - -
Apple/Scab
Leaves
41
Fruit
52
Cherry
Blossom blight 11
Cherry leaf spot 62
Grape/Powdery Mildew
Leaves
-Clusters
-(H. Wittig, 1997)
---
40
37
13
11
---
6
42
3
5
25
25
19
17
8
10
Compost Tea and Pathogens
Can Human Pathogens Grow In Compost Tea?
Addition of molasses led to Salmonella growth
(3 log or more)
No growth without molasses
Tea sprayed on strawberry plants, pathogens
grew on leaves
(B. Duffy, USDA-ARS)
Orchard Mulching and Cover Crops
Weed control – non-herbicide; suitable
for organic production
Moisture conservation
Fertility management, soil quality
Pest management ?
Orchard Cover Crops
Purposes:
 Prevent erosion, dust
 Reduce effects of equipment on
compaction
 Improve soil quality and nutrient
cycling
 Improve orchard IPM
Orchard Cover Crops
A good cover crop…
 Limited competition with the tree
 Poor habitat for rodents, other pests
 Good habitat for beneficial species
 Improves soil quality
Area and Timing of Weed Control – New York
‘Imperial Gala/M.26
Weed-free
area (ft2)
0
22
43
65
LSD(.05)
Cum. Yield
(kg/tree)
Cum. Growth
TCSA (cm2)
14.9
41.0
38.2
41.1
11.0
20.0
25.5
25.6
24.7
5.1
Planted in 1991; cumulative data for 1991-1995.
(Merwin & Ray, 1997)
Area and Timing of Weed Control – New York
‘Imperial Gala/M.26’
Weed Control Time
(days)
(month)
0
check
30
May
30
June
30
July
30
August
60
Ma, Jn
60
Jn,Jy
60
Jy, Au
90
Ma, Jn, Jy
90
Jn, Jy, Au
(Merwin & Ray, 1997)
Cumulative Yield
(kg/tree)
15.0
34.4
34.5
30.7
36.6
46.3
42.7
40.5
51.9
46.0
Costs of Orchard Weed Control – New York
System
Hay-straw mulch
Wood chip mulch
Weed collarTM
1.2 mil polyethylene
Belton-Sarlon plastic
Warren’s Weed-arrestTM
Herbicide strip
Mowed sodgrass
Clean cultivation
Cost (US$/acre/yr)
Materials
Labor
Total
300-400
145
300-550
0-20
295
130-315
9800
200
10,000
150
35
185
735
35
190-770*
1800
35
395-1835*
10
5
15-50
30
40
70-100
15
35
50
*cost based on 1-4 yr life of material
(Merwin, 1995)
Orchard Floor Management – New York
Soil Changes Over 5 Years
SOM
Treatment
(g/kg soil)
Mowed sod
5.6
Straw mulch
6.2
Glyph. 5’ strip
4.9
Tilled
4.5
LSD(.05)
1.0
(Merwin & Stiles, 1994)
NO3-N
(kg/ha)
6.3
37.6
8.3
53.2
P
(kg/ha)
5.7
28.5
6.4
4.7
30.1
12.0
K
(kg/ha)
209
1230
201
188
163
Effect of Orchard Floor Management on Tree
Mortality After 6 Years - New York
Tree mortality (%)
40
30
20
10
0
Mow
(Merwin & Stiles, 1994)
Straw
Glyph 5
Tilled
Wood chip mulch,
Wenatchee, WA.
Shredded paper mulch,
Wenatchee, WA
Fall-planted Dwarf white clover
Fall-planted Oriental mustard
Spray-on paper mulch
Orchard Mulching Trials – Summerland, BC
Bulk Density: biosolids treatments 0.92 vs. check 1.51
Moisture Retention: biosolids, composted biosolids sign. >>
check
Soil Temperature: maximums lower under mulches, except
greatest (+10oC) under geotextile
Infiltration Rate: inhibited by geotextile; all other mulches
sign. >> check
Orchard Mulching Trials – Summerland, BC
5th Leaf Spartan / M.9
TCSA
Roots
Yield
(mm2)
1.
2.
3.
4.
5.
6.
7.
Check (glyphosate)
Biosolids (Vancouver)
Paper mulch
2+3
Composted biosolids + 3
Alfalfa hay
Geotextile
(Hogue et al., 2000)
1011 b
1052 b
1565 a
1490 a
1406 a
1203 b
1125 b
(g/0.018m3)
11.3 c
16.9 bc
28.7 abc
41.8 a
38.7 a
35.2 ab
19.1 bc
(kg/tree)
10.3 c
11.2 bc
13.0 ab
13.9 a
14.9 a
14.0 a
12.7 abc
WVC Mulch Trial
Treatments compared to Control:
3-yr
TCSA
2-yr
Yield
2001
Yld Eff.
Alfalfa
+63%
+40%
+60 (ns)
Clover
+30%
+35%
+130%
Woodchip +26%
+ 0%
+105%
WVC Mulch Trial
SPAD units
Leaf Greenness - 2000
60
50
40
30
20
10
0
Control
Wood chip
Paper
Alfalfa
Mustard
Rye
122
143
172
Julian days
191
Clover mow
Clover herb
N Release from Clover Living Mulch
lbs/acre
Nitrate in Tube
80
70
60
50
40
30
20
10
0
07/24/2001
07/31/2001
08/07/2001
A
B
C
D
E
F
Trt
A = Control + Cover
D = Clover – Cover + Clippings
B = Control + Cover + Clippings
E = Control (no tube)
C = Clover + Cover + Clippings
F = Clover (no tube)
N Release from Clover Living Mulch
lbs/acre
Nitrate in Tube WVC-M 2001
60.0
50.0
40.0
30.0
20.0
10.0
0.0
A
B
C
D
E
F
Treatment
8/21/01
8/28/01
A = Control + Cover
B = Control + Cover + Clippings
C = Clover + Cover + Clippings
9/4/01
D = Clover + Cover
E = Control (no tube)
F = Clover (no tube)
WVC Mulch Trial
Weed Biomass 9/99
160
Weed DM (g/m2)
140
9/21/99
b
120
100
80
60
40
a
a
20
a
0
Control
Wood chip
Paper
Alfalfa
400
WVC Mulch Trial
BL weeds/m2
350
300
250
200
150
100
50
0
Weed Control by
Mulches – 6/1/00
% weed cover
Control
Wood
chip
Paper
Alfalfa
Mustard
Rye
Clover
Alfalfa
Mustard
Rye
Clover
50
45
40
35
30
25
20
15
10
5
0
Control
Wood
chip
Paper
Nem atodes / 100m l soil
Effect of Mulches on Nematodes in
Orchard Soil - Summerland, BC
600
Check
500
VBio
400
PM
300
VBio+PM
200
KBio+PM
100
AlfM
0
Bactiv. (x10)
(Hogue et al., 1998)
Omni/Pred
Pratylenchus
Geotex
Pest Reduction with Cover Crops
Cover crops can control tree vigor through
regulation of N and water.
Apple (WV) – lower aphid populations in trees with
cover crop than with herbicide strip; also 50% less
powdery mildew, slightly less scab, and no fireblight
with lower vigor (Brown & Schmitt, 1996)
Apple (BC) – much less aphid infestation with white
clover/grass cover vs. rye, herbicide strip, weed
barrier; clover mix competed with trees, reduced
vigor, which reduced aphids (Haley & Hogue, 1990)
Pest Reduction with Cover Crops
Successful examples usually involve a specific pestpredator relation.
Pecans (GA) – control of pecan aphid with convergent
lady beetle; grow cover crop of hairy vetch; produced
two generations of lady beetles, reaching 143,000/acre;
migrated from ground cover (senescing) to pecan trees
at time when aphids are reaching peak levels; effective
biocontrol achieved (Tedders, 1983)
Citrus (China) – control of citrus red mite by natural
enemies (Amblyseius spp.) encouraged on the weed
Ageratum conyzoides; cover is planted or conserved;
used on over 135,000 ha of citrus (Liang & Huang)
Cover Crops in Apples – Royal City, WA
Pest / beneficial ratios
3 best
Bug ‘n Breakfast Mix
Special Insectary
Special cover
(Granatstein, 1995)
5.6
6.2
7.0
3 worst
Grass B3
Grass BP
Grass B1
31.8
17.9
14.6
Effect of mowing on insect fauna in pears
Hood River, OR
Ground beetles
Floor
Spiders
Earw igs
Harvestmen
Unmowed
Monthly
Staphylinidae
0
0.2
0.4
0.6
0.8
1
Density (ratio to weekly mowing)
(Horton, 1998)
1.2
Effect of mowing on insect fauna in pears
Hood River, OR
Parasitoids
Floor
Damselbugs
Spiders
Unmowed
Lacew ings
Monthly
0
(Horton, 1998)
2
4
6
8
Density (ratio to weekly mowing)
10
Effect of mowing on insect fauna in pears
Hood River, OR
Ladybugs
Floor
M inute P. Bug
Big-eyed Bugs
Unmowed
Syrphid flies
Monthly
0
5
10
15
Density (ratio to weekly mowing)
(Horton, 1998)
20
Effect of mowing on insect fauna in pears
Hood River, OR
Tree
Parasitoids
Spiders
Unmowed
Monthly
Deraeocoris
0
0.5
1
Density (ratio to weekly mowing)
(Horton, 1998)
1.5
Effect of mowing on insect fauna in pears
Hood River, OR
Psylla
(beat trays)
Tree
Spider mites
Unmowed
Spider mites
(leaf samples)
Monthly
0
(Horton, 1998)
1
2
3
Density (ratio to weekly mowing)
4
Effect of mowing on insect fauna in pears
Hood River, OR
Floor
Lygus
Stinkbugs
Unmowed
Monthly
Aphids
0
4
8
12
16
20
24
28
32
Density (ratio to weekly mowing)
(Horton, 1998)
36
40
Enviroscan Mulch Trial
An automated system that
continuously measures soil
moisture content.
Enviroscan
probe
Individual
sensors
Access tube
WVC – Enviroscan Results
Mulch
No mulch
Wood chip mulch led to 20-25% less
moisture depletion between irrigations.
Soil Depth (cm)
Effect of Orchard Mulching on Soil
Moisture Depletion
50
30
20
10
0.0
0.5
1.0
1.5
Moisture Depletion (mm)
Mulch
Unmulched
2.0
Effect of Orchard Mulching on Soil Moisture
Depletion
Depletion as % of total
100%
80%
10
60%
20
30
40%
40
20%
50
0%
Mulch
Unmulched
(-)Centibars
WVC-M Tensiometers 10cm
0.0
-20.0
-40.0
-60.0
-80.0
5/18
6/8
6/29
7/20
8/10
Date 2001
B 10cm
A 10cm
(-)Centibars
0.0
8/31
9/21
G 10cm
WCV-M Tensiometers 30cm
-20.0
-40.0
-60.0
-80.0
5/18
6/8
6/29
7/20
8/10
Date 2001
B 30cm
A 30cm
8/31
G 30cm
9/21
Summerland, BC - Cumulative Water Use
L H2O used (15/06 to 23/08)
1200
1000
800
600
400
Mulch
No mulch
200
0
0
5
10
15
20
25
30
Trunk Diameter (mm)
35
40
45
Mulching Summary
• Moisture monitoring alone reduced
irrigation frequency by 50%
• Mulching reduced moisture depletion
another 20-25% on established trees
• Mulches can provide adequate weed
control
• Low-cost approaches are needed to
make mulching practical
Good Bets for Soil Health
 Reduce tillage, stop erosion, maintain
soil structure
 Keep the soil covered
 Maintain adequate C, N inputs
 Promote diversity, rotate crops
 Monitor soil moisture to avoid excess
Knowledge Gaps
• Pest ecology in complex
systems
• Pest / nutrition interactions
• Manipulation of rhizosphere
• Chemical ecology of plants
• Nutrient flow through orchard
Orchard Floor Management
Net effect is the interaction of:






plant species
management
nutrient levels
pests
weather
irrigation
Harder to predict single component
impacts.