View
114
Download
1
Category
Preview:
DESCRIPTION
69th SWCS International Annual Conference “Making Waves in Conservation: Our Life on Land and Its Impact on Water” July 27-30, 2014 Lombard, IL
Citation preview
Agricultural Phosphorus in Western Lake Erie – Opportunities,
Uncertainty and Competing Interests
KEVINKING
USDA‐ARS
DOUGSMITHUSDA‐ARS
PETEKLEINMANUSDA‐ARS
ANDREWSHARPLEYU. ARKANSAS
LAURAJOHNSONHEIDELBERG U.
Lake Erie Eutrophication Historical Success
Source: Baker and Richards, Heidelberg University
Lake Erie Eutrophication Today’s harmful algal blooms
Source: NOAA
2011 algal bloom
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Dis
solv
ed R
eact
ive
Pho
spho
rus
FWM
C (m
g/L)
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
1975 1980 1985 1990 1995 2000 2005 20100.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Maumee
Sandusky
Cuyahoga
River % Agric. % Urban % Forest
Maumee 73 11 7
Sandusky 78 8 9
Cuyahoga 9 40 34
Source: Johnson,Heidelberg University
Reversal of fortunedissolved phosphorus
DRP (kg P/ha)
TP (kg P/ha)
Maumee 0.293 1.32
Sandusky 0.415 1.81
Honey Cr. 0.577 1.89
Rock Cr. 0.335 1.98
Low phosphorus loads< 2 kg/ha
Source: Johnson,Heidelberg U.
7.5
5.0
2.5
0
Par
ticul
ate
P (k
g ha
-1)
P en
richm
ent r
atio
1
6
4
2
810
Particulate PP enrichment ratio
Erosion (tonnes ha-1)10 10010.10.010.001
Phosphorus enrichment ratioThe lower the erosion, the greater the
P concentration of the sediment
Source: Sharpley,University of Arkansas
In‐channel phosphorusSedimentation
Mark Tomer, ARS
Mark Tomer, ARS
Joe Magner, Univ. Minn.
Entrained wetlands
Constructed wetlands
Two‐stage ditch
Stream restoration/reconnecti
on
Field management of phosphorusControlling source and transport
PhosphorusSource
TransportMechanism
Critical Critical source area
Hydrologic connectivityFlat, internal drainage
Field management of phosphorusControlling source and transport
PhosphorusSource
TransportMechanismTransportMechanism
Critical source area
Hydrologic connectivityFlat, internal drainage
P Loss (kg/ha)
10
20
30
0 421mg/kg
447mg/kg
20012002
20032004
2005
Kleinman et al., 2007 (J. Soil and Water Conserv.)
1500
5000
1000
Precip(m
m)
In hydrologically connected systemsLoads driven by precipitation
Lake Erie Eutrophication Harmful algal blooms
Satellite Images: NOAA/NASA
2012 algal bloom
St. Joe’s Watershed 2011 2012Annual 45” 25”March‐June 19” 7” Source: Smith,
USDA‐ARS
2011 algal bloom
In hydrologically connected systemsLoads driven by runoff/drainage
Conservation Technology Innovation Center (Purdue)
Drainage and subsurface P loss Many parallels with surface runoffDissolved P in tile drainage (m
g/L)
Soil test P, upper 2 inches (mg/kg)Source: King,USDA‐ARS
Tile drainage phosphorus loss Surface runoff through pipes
Source: M. Shipitalo, USDA‐ARS
Mar Apr May
Flow
dep
th (f
t)
0.00.20.40.60.81.01.2
DR
P co
nc. (
mg/
L)
0.00.20.40.60.81.0
flow depth concentration
Source: King, USDA‐ARS
Source: Shipitalo, USDA‐ARS
Concentration of P along flow pathwaysIncidental transfers of applied P
.
Dates custom applicators were in fields
Source: Johnson, Heidelberg U.
0
1
2
3
4
Before Broadcast Tilled‐in
Concentration of P along flow pathways4R strategy – placement of applied P
Dairy slurry
P loss in
leachate (kg/ha)
Kleinman et al., 2009
Tillage to incorporate manure and disrupt
macropores
Concentration of P along flow pathways4R strategy – rate/timing of applied P
0
2
4
6
8
10
12
0 50 100 150 200 250 300 350Days since Manure Application
100 T/ha35 T/ha
200 T/ha
Dissolved P in tile drainage (m
g/L)
Klausner et al., 1976; Brookes et al., 2000
Days after manure was applied
Source: Johnson, Heidelberg U.
0
12
8
6
4
2
10
3628
55 6049
34
26
Vertical stratification of soil PSupports tillage where high P is a concern
Sampling de
pth (in
ches)
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Dissolved P (m
g/L)
Maumee
Sandusky
20101980 20001990
No‐till expands
Mostly rotational no‐tillRota onal no ll →59%Con nuous no ll → 8%
Kleinman et al., 2010 (Canadian J. Soil Science)
0
100
200
300
400
500
600
2000 2002 2005 2007 2009
Meh
lich‐3 soil P (m
g/kg)
Lime
0
1
2
3Dissolved P in ditch flow
(mg/L)
Legacy PNo change after one decade
• In stream/channel• Edge‐of‐field• In field
All of the above, and moreTraditional conservation strategies don’t solve dissolved nutrient losses
In‐ditch filters Edge‐of‐field filters
Source: Bryant, USDA‐ARS
Unnecessaryconflict
Once the soil is healthy and has good water infiltration and water holding capacity it may be possible to surface apply fertilizer knowing that there will be little or no water runoff and that the nutrients will infiltrate and percolate through the soil via matrix flow.
This will allow the nutrients to interact and bond with the soil. In addition, fertility requirements will likely be lower in a healthy soil due to better nutrient retention and recycling. The overall retention of nutrients and improved soil biota can affect nutrient cycling, may increase efficiency and reduce fertilizer needs.
p. 38
No tillCover crops
Recommended