REDUCING NUTRIENT LOADS IN AGRICULTURAL LAND DRAINAGE SYSTEMS · 2010-09-17 · REDUCING NUTRIENT...
Transcript of REDUCING NUTRIENT LOADS IN AGRICULTURAL LAND DRAINAGE SYSTEMS · 2010-09-17 · REDUCING NUTRIENT...
REDUCING NUTRIENT LOADS IN AGRICULTURAL LAND DRAINAGE SYSTEMS
Keynote Presentation to10th
International Drainage Workshop
July 08, 2008Helsinki, Finland
ByChandra A. Madramootoo
McGill University, Montreal, Canadaand
Vice President Hon. ICID
Spring field conditions
Subsurface pipe drainage installation
Montreal Gazette June 2008
Montreal Gazette June 2008
Water quality impacts
DRAINAGE FOR:
•Crop production?•Water quality improvement?•Flood control?
Making best use of outlets
Drain outlets
Pumped outlet
Gravity outletGravity outlet
Surface inlet
Nitrogen Cycle
McGill Water Management Research Facility
St. Emmanuel, Qc
75 m
30 m15
m
N
Buildings
FDSIBuffer FDBuffer SI
Block C Block B Block A
Surface runoff plots
McGill Water Management Research Facility
St. Emmanuel, Qc
Field Layout
NO3-N Concentrations in mg/L
1998 1999FD SI FD SI
Jun 5.2 1.03 2.5 2.0Jul 5.1 1.5 2.5 1.5Aug 3.7 1.02 2.5 1.5Sep 2.7 0.7 2.5 1.5Oct 3.0 1.0 4.5 2.0Nov 3.2 1.0 4.5 2.0
Sample date
Denitrification rate (g N ha-1 day-1)†1996 1997
FD SI FD SI11 July15 July23 July6 Aug18 Aug22 Aug3 Sept.17 Sept.20 Sept.3 Oct.5 Oct.
—185—
31.3—
27.35.5—
14.3—
4.64
—225—
113*—
21.830.5*
—25.8—
15.3*
36.1—6.76.81.1—4.87.8—4.9—
38.1—
14.2*7.2
8.78*—
12.0*20.0*
—11.2*
—
Yield Increases due to Subirrigation McGill Water Management Research
Facility St. Emmanuel, QC
Treatment Grain corn yield (t/ha)2001 2002
Subirrigation 9.4 10.1
Non-irrigated 6.9 7.6
% increase 36% 33%
Site Locations
Missisquoi Bay
Pike River
3
4
21
H flume for surface runoff
Flow meter and sampler for Subsurface drainage
Instrument Shelter
Site DescriptionField Area Soil Type1 7 ha Sandy Clay Loam2 6 ha Sandy Loam3 2 ha Clay Loam4 3 ha Sandy Clay Loam
Field Drainage Crops1 Surface + Tile Corn, Soybeans2 Surface + Tile Alfalfa, Corn3 Only Surface Corn, Cereals4 Only Surface Hay, Pasture
Site Description
Field Soil Test P (kg/ha)
% P sat
1 114 5.3
2 373 22.0
3 38 1.6
4 72 4.0
Understanding the field hydrologic and water quality processes –
Measurements and modelling
1000 mm
100 mm
400 mm
450 mm
TILE DRAINAGE
Spring Season Hydrology
Importance of the seasonEnvironmentally sensitive Snowmelt High Intensity stormsFertilizer ApplicationsHigh Runoff RatioHigh Erosion Potential
Field hydrology (% of total rain)Runoff (10% - 25% dry - wet)Tile drainage (55% - 66% dry - wet)
Year Field Rain SS SRO %SS %SRO
mm mm mm
2002 1 342.1 229 61.4 66.9% 17.9%
2 376.3 277.5 31.8 73.7% 8.5%
2003 1 232.3 134.4 22 57.9% 9.5%
2 257.8 190 12.8 73.7% 5.0%
2004 1 240.5 123.8 n/a 51.5% n/a
2 244.3 181.8 n/a 74.4% n/a
2006 1 368.4 243.9 90.1 66.2% 24.5%
2 364.2 206.2 38.6 56.6% 10.6%
3 346.5 - 51.3 - 14.8%
Seasonal Phosphorus Loads
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
Measured Simulated Measured Simulated Measured Simulated Measured Simulated
Site #1 Site #2 Site #1 Site #2
Particulate P Dissolved P
Site | Season
Load
(kg/
ha)
Spring Summer Fall Winter
Particulate P is the main form of phosphorus exiting the fieldP in surface runoff (60%) and subsurface flow (40%)Mean concentrations consistently exceed MENV guidelines of 0.03 mg/l
0
100
200
300
400
500
600
0 20 40 60 80 100Drain spacing (m)
Flow
(mm
)
0
25
50
75
100
Tile
dra
inag
e/ T
otal
flow
) %
.
SubsurfaceSurface
%
0
100
200
300
400
500
600
0 20 40 60 80 100Drain spacing (m)
Flow
(mm
)
.
0
25
50
75
100
(Tile
dra
inag
e/To
tal F
low
) %
.
Subsurface
Surface
%
Site B Site A
DRAINMOD Simulated Surface Runoff and Tile Flows for Different Drain Spacings
Sandy clay loamSandy loam
0
0,3
0,6
0,9
1,2
1,5
1,8
0 0,3 0,6 0,9 1,2 1,5 1,8Log (Tile drainage depth (mm) + 1)
Log
( TP
(g/h
a) +
1)
.
0
0,5
1
1,5
2
2,5
0 20 40 60 80 100Drain spacing (m)
P lo
ads
(kg/
ha/y
r)
TP
TPP
TDP
0
0,2
0,4
0,6
0 20 40 60 80 100Drain spacing (m)
Plo
ads
(kg/
ha/y
r)
TDP
TP
TPP
(a) Site 1 (b) Site 2
Simulated P Concentrations in Tile Flow for Different Drain Spacings
Sandy clay loam Sandy loam
0
1
2
3
4
5
6
0 20 40 60 80 100Drain spacing (m)
P lo
ads
(kg/
ha/y
r)
. TPTPPTDP
0
0,4
0,8
1,2
0 20 40 60 80 100Drain spacing (m)
P lo
ads
(kg/
ha/y
r)
TDP
TPP
TP
(a) Site 1 (b) Site 2
Simulated P Concentrations in Surface Runoff for Different Drain Spacings
Sandy clay loam Sandy loam
Watershed BMP selection - SWAT Modelling
40
50
60
70
80
90Pasture
Alfalfa
Corn2Past2
Corn2 Alfalfa2
Corn3Past
Actual
Corn2Soy2
Corn2 SoyGrn
CornSoyGrnPast
Corn Mono
0.00.51.01.52.02.53.03.54.0Pasture
Alfalfa
Corn2Past2
Corn2Alfalfa2
Corn3Past
Actual
Corn2Soy2
Corn2SoyGrn
CornSoyGrnPast
CornMono
0.46
0.48
0.50
0.52
0.54
0.56
0.58
Pasture
Alfalfa
Corn2Past2
Corn2Alfalfa2
Corn3Past
Actual
Corn2Soy2
Corn2SoyGrn
CornSoyGrnPast
CornMono
0.0
0.5
1.0
1.5
2.0Pasture
Alfalfa
Corn2Past2
Corn2Alfalfa2
Corn3Past
Actual
Corn2Soy2
Corn2SoyGrn
CornSoyGrnPast
CornMono
Management Practice ScenariosRunoff Ratio Sediment
Total PhosphorusNitrate-nitrogen
Conventional Conservation No Till
THANK YOU!A special thanks to all my graduate students, postdocs, and research assistants.
I acknowledge all our funding agencies particularly NSERC, CFI, FQRNT, Max Bell Foundation.
Water table management
• Subirrigation• Controlled drainage• Water quality benefits• Agronomic benefits
Drained Vs Undrained Fields20 May, 2006 Event Concentrations
0
100
200
300
400
500
600
700
800
VER-SRO-COMP GAG-SS-COMP MES-SRO-GRAB MAR-SS-COMP
Sample
Con
cent
ratio
n (u
g/l f
or P
, mg/
l for
MES
)
MES P-BIO P-ORTHO P DISS P TOTAL
Undrained; surface runoff)
Undrained; surface runoff)
Drained; subsurface drainage)
Drained; subsurface drainage)