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Effects of afforestation on soil physical properties
Mario Pérez Bidegain
Department of Soils and Water
Facultad de Agronomía-Udelar
September 12, 2018
Outline
• Background
• Results
• Conclusions
Background
Source:http://www.mgap.gub.uy/sites/default/files/multimedia/1927_total_uruguay_31_8.jpg
Background
Background
• Change from agriculture, or native pasture to afforestation
• Change on root system
• Change on Soil Organic Matter (SOM) supply/distribution
Results
• Does land use change affect soil physical properties?
Results
Pérez Bidegain et al, 2001
Volumetric soil water content, soil erodibility, and runoff on different soil under Eucalyptus (8-10 yr old) and Pasture
**
**
NS
Results
CSIC-UdelaR / Sector Productivo (Los Piques) 2001-2004
Results
• Water Drop Penetration Time (WDPT) for three vegetations:
native pasture, Pinus taeda and Eucalyptus grandis in a Ultisol
Acrisol Álbico
0,0
2,0
4,0
6,0
8,0
10,0
12,0
manejo
tiem
po
(seg
un
do
s)
campo
pino
eucalyptus
Rodriguez, J (2007)
• Water repellency increases after changing native pastures to Eucalyptus sp. and Pinus taeda.
• Water repellency is a consequence of microbiological and/or biochemical reactions.
• Organic hydrophobic compounds are present in the three soil uses, but their quantities were higher in afforested soils.
• An increase in hydrophobicity was associated to less Water Holding Capacity, principally in soils below eucalyptus vegetation.
Results
Results
0
100
200
300
400
500
600
700
800
0 20 40 60 80 100 120
Tin
e (
seco
nd
s)
Soil matric potential(-KPa)
Pasture
Row
Between rows
Slightly
Moderately
Strong
Field Book for describing and sampling Soils V.3 NSSC-NRCS-USDA
Bentancor y Pérez Bidegain (2017, unplublished)
Results
• Does land use affect soil water content?
Results
• Norh region
• Hapludalfs y Hapludults
• Sand stones derived soils (Triassic)
• Slopes (8-15%)
• A horizon 50 to 100 cm deep (Sandy loam)
• Bt horizon (Sandy clay loam)
• Natural fertility: low
• Soil erosion risk: high
Results
Hapludalfs Hapludults
Results
Soil water dynanics
Results
99
A
C
A
Bt
80
D
F
A
E
Bt
C
38
104
72
Watersh.1
C
A1
A2
Bt
C
78
133 C
AB AB
48
60
114
Bt
Watersh.2
Results
Soil Horizon Depth Sand Silt Clay Organic
matter
pH
(H2O)
pH
(KCl)
cm % weight %
C (summit) A1 78 83.2 8.9 7.9 0.4 5.2 4.2
A2 21 80.1 9.5 10.4 0.3 5. 4.1
Bt 34 58.1 10.8 31.3 0.3 4.8 3.7
C 61.2 10.5 28.3 0.2 4.8 3.7
F
(footslope)
A 38 74.2 13.1 12.7 1.0 5.1 4.1
E 34 75.9 12.8 11.3 0.8 5.1 4.1
Bt 32 63.1 12.3 24.6 0.7 5.1 3.8
Results Soil bulk density (Mg.m-3), volumetric soil water content (-10kPa) and macroporosity in soil C (summit) in pasture and forest (10 yrs after the plantation)
Depth BD θ Mac
P Pine PIR P Pine PIR P Pine PIR
2.5-7.5 1.54 1.41 1.36 22.2 20.1 18.5 19.7 26.9 30.3
22.5-
27.5
1.53 1.51 1.49 15.8 19.5 17.7 26.5 23.6 26.1
78-99 1.54 1.46 1.48 20.5 18.1 17.8 21.6 26.8 26.5
99-133 1.44 1.38 1.55 33.5 34.1 16.6 12.2 13.6 4.8
Results
Depth BD θ Mac
P Pine PIR P Pine PIR P Pine PIR
2.5-7.5 1.47 1.29 1.34 24.2 25.2 22.4 20.1 26.4 27.1
22.5-
27.5
1.48 1.41 1.48 19.7 20.6 20.1 24.3 26.2 23.4
38-72 1.58 1.57 1.56 21.5 17.7 19.3 18.7 23.1 22.0
72-104 1.51 1.50 1.44 33.2 33.4 34.0 9.9 10.0 10.4
Soil bulk density (Mg.m-3), volumetric soil water content (-10kPa) and macroporosity in soil F (footslope) in pasture and forest (10 yrs after the plantation)
Results Native pasture 14 yr. old Pine
Results
Piaggio et al 2017
A a
B
b
Results
• Constant head
• Surface: 5 cm depth
• Subsurface: 20 cm depth
• 12 yr old Pine
• Hapludalf
Results
0.0 2.0 4.0 6.0 8.0 10.0 12.0
Row
Between row
Native pasture
cm.h-1
Lab saturated hydraulic conductivity
A a
a
B
Surface Sub surface
0.0 2.0 4.0 6.0 8.0 10.0 12.0
Row
Between row
Native pasture
cm.h-1
Lab saturated hydraulic conductivity
B
b
Aa
Results
Results
0
100
200
300
400
500
600
01
/09
/20
02
14
/01
/20
04
28
/05
/20
05
10
/10
/20
06
22
/02
/20
08
06
/07
/20
09
18
/11
/20
10
01
/04
/20
12
14
/08
/20
13
27
/12
/20
14
10
/05
/20
16
Soil
wat
er
con
ten
t (m
m)
C Pasture
C Pine (row)
Summit
9/44 Pasture > Pine
4/44 Pine row > Pasture
Results
Summit
2/44 Pine between rows > Pasture
Results
0
100
200
300
400
500
600
01
/09
/20
02
14
/01
/20
04
28
/05
/20
05
10
/10
/20
06
22
/02
/20
08
06
/07
/20
09
18
/11
/20
10
01
/04
/20
12
14
/08
/20
13
27
/12
/20
14
10
/05
/20
16
Soil
wat
er
con
ten
t (m
m)
F Pasture
F Pine (row)
Footslope
22/44 Pasture > Pine (row)
5/44 Pine (row) > Pasture
Results
Footslope
24/44 Pasture > Pine (between rows)
Conclusions
• Land use change (from pasture to afforestation) affected:
Soil physical propeties
Soil water dymamics (soil management, topographic position)
Soil water repellency ( Hidrological implications?)
Conclusions
• Link:
Soil physical and soil chemical properties
Soil management practices &
Hidrological implications
Thanks you [email protected]
