Orchard Groundcover Management - Amaya Atucha

Orchard groundcover management
effects on trees, soil and water
resources
February, 2013

Long-term studies of orchard groundcover
management systems (GMSs)
Effects on :
ü Tree physiology and yields
ü Soil physical, chemical and biological conditions
ü Nutrient dynamics
ü Agrochemical leaching and runoff

Long-term Effects of Four Groundcover Management Systems in an
NY Apple Orchard

Objective
To determine the impacts of various GMS
treatments on tree growth, nutrition, and
production and to ascertain the effects of various
GMS treatments on soil physical and edaphic
conditions over several decades.

Pre-emergence
Post-emergence
Sod Bark Mulch

Cumulative TCSA (cm²)
200
180
160
140
120
100
80
60
40
20
0
1992
**
1993
**
1994
*
1995
1996
Tree growth
1997
1998
*
1999
**
2000
*
2001
**
2002
*
2003
PreHerb PostHerb Sod Mulch
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at ** P≤0.05 or * 0.1
**
2004
**
2005
**
2006
**
2007
**
2008

Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at P≤ 0.05

Fruit Yield (kg·tree -1 )
120.0
100.0
80.0
60.0
40.0
20.0
0.0
**
1994
**
1995
**
1996
1997
**
1998
Fruit Yield
*
1999
2000
*
2001
2002
**
2003
2004
PreHerb PostHerb Sod Mulch
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at ** P≤0.05 or * 0.1
2005
2006
2007
2008

Long-term effects of GMSs treatments on soil nutrient availability (kg/ha)
and pH.
Variable 1992 1993 1995 2000 2005 2006 2007
NO־³
PreHerb 11.4 47.7 a 19.5 13.1 b N/D N/D 2.6 b
PostHerb 11.2 24.6 ab 8.7 12.7 b 5.4 b
Sod 10.8 11.0 b 2.6 12.7 b 4.0 b
Mulch 11.2 11.1 b 4.8 15.7 a 23.9 a
P
PreHerb 1.2 3.2 a 2.8 a 7.1 b 2.1 b 2.2 1.0 b
PostHerb 1.4 2.8 ab 0.7 ab 6.0 b 2.1 b 2.4 1.6 b
Sod 1.0 1.5 b 0.3 b 3.7 b 3.2 b 1.9 1.2 b
Mulch 1.3 2.7 ab 1.1 ab 16.4 a 22.0 a 7.1 10.0 a
K
PreHerb 122.3 ab 169.5 ab 74.4 ab 375.2 410.2 ab 249.0 190.5
PostHerb 127.5 ab 191.3 ab 74.3 ab 317.3 328.5 b 207.8 214.5
Sod 106.5 b 148.5 b 56.1 b 306.1 420.5 ab 193.5 192.0
Mulch 158.3 a 200.3 a 93.9 a 388.3 595.4 a 264.0 299.3
Ca
PreHerb 4041.0 4733.3 2028.1 3124.8 b 3216.7 b 3620.3 b 3364.5 b
PostHerb 3192.8 4284.0 1509.0 2639.5 b 3191.3 b 3551.3 b 3060.8 b
Sod 3291.0 4107.0 1525.0 2284.8 b 3086.8 b 3276.8 b 3087.0 b
Mulch 4935.0 4700.3 1760.7 5730.7 a 12799.0 a 8248.5 a 9559.5 a
Mg
PreHerb 682.7 912.4 a 418.5 957.6 898.8 810.1 a 862.3
PostHerb 597.4 857.3 ab 367.6 767.2 792.9 772.3 a 805.8
Sod 629.0 799.8 ab 353.2 774.7 889.1 690.5 ab 805.1
Mulch 612.5 705.0 b 342.3 643.7 988.1 544.7 b 760.1
Mn
PreHerb 38.6 27.7 b 71.3 b 234.1 58.4 b 44.6 b 26.9 b
PostHerb 36.0 30.0 b 76.0 b 154.6 44.7 b 40.2 b 32.7 b
Sod 31.7 32.0 b 81.8 ab 121.7 54.6 b 35.1 b 29.5 b
Mulch 47.0 48.6 a 108.0 a 185.5 117.5 a 75.2 a 63.5 a
pH
PreHerb 6.9 7.1 7.1 5.9 6.9 bc 6.8 bc 7.1 ab
PostHerb 6.9 7.2 7.0 5.9 7.0 ab 7.0 ab 6.9 b
Sod 7.1 7.2 7.0 5.8 6.6 c 6.6 c 6.8 b
Mulch 6.7 7.4 7.0 6.4 7.4 a 7.2 a 7.5 a
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at P≤ 0.05

Percent nitrogen (N), percent carbon (C), and C-to-N ratio in soil
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at P≤ 0.05

Yao et al. (2005) Orchard floor management prac7ces that maintain vegeta7ve or biomass groundcover s7mulate soil
microbial ac7vity and alter soil microbial community composi7on. Plant and Soil. 271:377-­‐389

Oliveira et al. (2001) Soil physical condi7ons in a New York orchard aLer eight years under
different groundcover management systems. Plant and Soil. 234: 233-­‐237

• Total soil nitrogen (N) and carbon (C) content, C-to-N
ratios, and essential plant nutrients were much higher in
the Mulch soil after 16 years of treatments.
• Deterioration of soil physical properties, biological
activity, and soil fertility in weed-free plots.
• Post-emergence herbicides that reduce weed competition
during summer month may offer an optimal combination
of weed suppression and soil conservation.

Nutrient Cycling and Budgets under Four Groundcover Management
Systems (GMSs) in a NY Apple Orchard

Objective
• To measure and budget the major inputs and
outputs of N in an orchard after 15 years under
four different GMSs, with and without soil-
applied N fertilizer applications.

Nitrogen Budget
INPUTS INTERNAL
FLUXES
Fertilization
Irrigation and
precipitation
water N
Bark mulch
Recycling surface
vegetation
Leaf litter fall
Pruned wood
Soil N mineralization
OUTPUTS
Harvested fruit
Subsurface leaching
Surface Runoff

Litter decomposition study
• Litter samples: apple leaves,
fallen immature fruits and
surface vegetation.
• 3 bags with 40 g of litter
were placed under the tree
canopy
• Bags were removed after 6,
12 and 18 weeks and
analyzed to determine C:N

Nitrogen Budget
INPUTS INTERNAL
FLUXES
Fertilization
Irrigation and
precipitation
water
Recycling surface
vegetation
Leaf litter fall
Pruned wood
Soil Mineralization
OUTPUTS
Harvest fruit
Subsurface leaching
Surface Runoff

Leaf litter fall

Nitrogen Budget
INPUTS INTERNAL
FLUXES
Fertilization
Irrigation and
precipitation
water
Recycling surface
vegetation
Leaf litter fall
Pruned wood
Soil Mineralization
OUTPUTS
Harvest fruit
Subsurface leaching
Surface Runoff

PreHerb
PostHerb
Mowed Sod
Mulch
Sub-­‐surface water collec9on sta9on
Surface water collec9on sta9on
Tree (Empire on M.9/111)
Orchard OuElow
4” Perforated plot collec9on 9le
4” Solid 9le to collec9on sta9on
4” Perimeter isola9on 9le
Surface water collec9on 9le
Outline of the experimental site (DTS) at Lansing Source: M G Brown, 2005

Nitrogen Budget
INPUTS INTERNAL
FLUXES
Fertilization
Irrigation and
precipitation
water
Recycling surface
vegetation
Leaf litter fall
Pruned wood
Soil Mineralization
OUTPUTS
Harvest fruit
Subsurface leaching
Surface Runoff

Results

g N / kg of biomass
35
30
25
20
15
10
5
0
Nitrogen mineralization from groundcover
litter decomposition
32 66 96
2005
days
PreHerb PostHerb Sod Mulch
g N / kg of biomass
35
30
25
20
15
10
5
0
42 84 126
2007
PreHerb PostHerb Sod Mulch
days

Average nitrate-N (NO 3 -N) concentration (mg L –1 ) in
runoff and leachate samples collected from
June to Nov. 2005 and 2007
Treatment
Runoff N Concentration
(mg L -1 )
Leachate N Concentration
(mg L -1 )
June-November June-November
2005 2007 2005 2007
PreHerb 5.8 a 4.6 ns 4.1 b 0.6 b
PostHerb 3.1 ab 2.6 13.0 a 0.8 b
Mulch 1.6 b 5.5 10.0 ab 1.6 a
Sod 1.9 b 3.8 12.8 a 1.0 b
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at P≤ 0.05

Water flows (L·m -2 ) from surface runoff and sub-surface
leaching during May-Dec. of 2005 and 2007
Treatment
Surface Runoff Water
(L·m -2 )
May-Dec
Sub-surface Leaching Water
(L·m -2 )
May-Dec
2005 2007 2005 2007
PreHerb 11.6 b 32.9 ab 34.2 ns 44.7 b
PostHerb 30.7 a 87.9 a 47.7 41.5 ab
Mulch 6.7 b 6.6 b 53.5 61.7 a
Sod 21.0 ab 36.6 ab 42.3 51.4 ab
Letters in columns represent mean separation using Tukey’s honestly significant difference (HDS) at P≤ 0.05

A. EXTERNAL INPUTS
PreHerb
(kg N·ha - 1·yr -1 )
Groundcover Management Systems (GMSs)
PostHerb
(kg N·ha - 1·yr -1 )
Sod
(kg N·ha - 1·yr -1 )
Mulch
(kg N·ha - 1·yr -1 )
2005 2007 2005 2007 2005 2007 2005 2007
Fertilizer application 60.0 0 60.0 0 60.0 0 60.0 0
Mulch Biomass N 0 0 0 0 0 0 169.2 84.6
Rain water 0.9 1.2 0.9 1.2 0.9 1.2 0.9 1.2
Irrigation Water 1.8 0.03 1.8 0.03 1.8 0.03 1.8 0.03
Total Inputs 62.7 1.23 62.7 1.23 62.7 1.23 231.9 85.3
B. INTERNAL FLUXES
Recycling surface vegetation 15.1 19.5 20.9 21.5 23.6 29.9 25.1 24.4
Soil Mineralization 11.2 12.3 13.5 14.1 14.8 17.2 17.8 18.9
Leaf litter Fall 16.4 10.7 11.6 14.2 10.3 17.9 10.3 15.9
Pruned wood 4.1 11.5 5.6 13.2 4.8 14.5 5.2 14.9
Total internal fluxes 46.8 54.0 51.6 63.0 53.5 79.5 58.4 74.1
C. OUTPUTS
Harvested fruit* 69.3 57.3 82.2 70.3 54.9 61.0 80.9 78.0
Surface runoff 4.0 13.5 3.1 20.8 1.4 12.8 1.2 11.1
Subsurface leaching 16.1 5.2 18.9 5.2 16.1 5.9 20.9 7.4
Total outputs 89.4 76.0 104.2 96.3 72.4 79.7 103.0 96.5
BALANCE= (A+B)-C 20.1 -20.8 10.1 -32.1 43.8 1.1 187.3 62.9

• Soil N mineralization and recycling groundcover biomass
accounted for over 60% of internal fluxes in both years.
• Harvested fruit represented > 70% of N outputs in both years.
• Most N losses occurred through leaching rather than runoff,
regardless of GMS.
• Positive balance for N supply in Sod and Mulch at this orchard
• Potential long-term problems with N leaching in orchards that
receive high annual inputs of compost, biomass mulch, or
other organic nutrient sources.
• N deficit in both herbicide GMSs without N fertilizer inputs,
because of reduced internal N cycling in these GMSs

Ques7ons