2017 SWCS Annual Conference July 30-August 2, 2017 Monona Terrace Convention Center

1. Is It Working?
A look at the changing nutrient practices in the Southern
Willamette Valley Groundwater Management Area
Susanna L. Pearlstein, Jana Compton, J. Renée Brooks,
Alan Henning, Donna Schmitz, Audrey Eldridge
July 31, 2017
SWCS Madison, WI

2. Today’s Objectives
• Southern Willamette Valley
Groundwater Management Area
• Partnership for Improved Nutrient
Efficiency (PINE) Project
• Lysimeter NO₃¯-N concentrations
over time by crop type
• Comparison of current cropland with
1990s data
Photo: S. Pearlstein

3. Oregon Nitrogen Fertilizer Inputs
http://enviroatlas.epa.gov/enviroatlas/atlas.html

5. Willamette Valley
• Most rainfall occurs in winter months
• Mediterranean climate
• Over 200 different crops grown
S. Pearlstein

6. Percentage Nitrogen Contribution by Source
90%
4% 6% 0%
Crops
Septic Systems
CAFOs
Large Wastewater
Systems
Southern Willamette Valley
Groundwater Management Area

7. Partnership for Improved Nutrient Efficiency
Project Objective
Provide a tool that will help farmers, managers and
conservation groups quantify the water quality benefits of
practices that they are conducting or funding and use that
information to set priorities and inform water quality
trading.
Photo: S. Pearlstein

8. Alan Henning, US EPA Region 10
Jana Compton, US EPA-ORD
Susanna Pearlstein, ORISE
Audrey Eldridge, Oregon DEQ
Priscilla Woolverton, Oregon DEQ, GWMA lead
Bart Faulkner, US EPA-GWERD
Ken Forshay, US EPA-GWERD
J. Renée Brooks, US EPA-ORD
Donna Schmitz, Benton SWCD
Teresa Matteson, Benton SWCD
Dave Downing, Upper Willamette SWCD
Tom Snyder, USDA NRCS
Paul Measles, Oregon Dept. of Agriculture
Carrie Sanneman, Willamette Partnership
Denise Kalakay, Lane Council of Governments
John Selker, Oregon State University
Project support:
EPA – Field sampling, isotope analysis
DEQ – Chemistry analysis in-kind
ODA Fertilizer Fund – Equipment, soils work
SWCD – Soil health
NRCS, SWCS, GWMA, Land owners – Sites
WP – Modeling edge-of-field loss
LCOG – Outreach, Expert Panel

9. N
N
Harvest
Study expectations based
on changing practices
1990s study Current study
N
N
Harvest
Improvements
Irrigation Practices
Breeding, Production
Fertilizer management
Right source
Right rate
Right time
Right place

10. Field Measurements
Farm information
• Crop harvest
• Irrigation timing
• Irrigation nitrate levels
• Fertilizer type, timing
Soil information
• Soil quality measures
• Soil moisture probes
Groundwater
Monitoring wells
Analyze for:
• Nitrate
• Volume
• δD, δO
1 m
depth
PCAP Prenart
Water sampler
Photo: S. Pearlstein

11. Study sites – crop types and distribution
peppermint
38%
Grass seed
9%Blueberry
9%
Orchard
10%
Row
crops
29%
wheat
5%
1990's Crops
Peppermint
13%
Grass
seed
33%
Blueberry
7%
Orchard
7%
Row
crops
27%
Wheat
13%
Current Study Crops

12. Preliminary
Results

13. 0
10
20
30
40
50
60
70
80
90
100
January
April
July
October
January
April
July
October
January
April
mg/LNO3-N100cmsoildepth
Control Sites, Out of Farming
2015 2016 2017

14. 0
10
20
30
40
50
60
70
80
90
100
January
April
July
October
January
April
July
October
January
April
July
October
January
April
mg/LNO3-N100cmsoil
depth
Nitrate-N Concentrations: Peppermint
Mint #1
Mint #2
Mint #2 Tile Drain
Mint #2 TD L2
Mint #2 L2
2014 2015 2016 2017
0
10
20
30
40
50
60
70
80
90
100
Nov.93
Feb.94
May.94
Aug.94
Nov.94
Feb.95
May.95
Aug.95
Nov.95
Feb.96
May.96
Aug.96
Nov.96
Feb.97
May.97
Aug.97
Nov.97
Jan.98
Apr.98
ppm(mg/L)NO3-N Nitrate-N Concentration in Groundwater Recharge: Peppermint
Mint #1
Mint #3
Mint #4
Mint #5
Mint #6
Mint #7
330 kg N ha¯¹
168 kg N ha¯¹ 336 kg N ha¯¹

15. 0
10
20
30
40
50
60
70
80
90
100
January
April
July
October
January
April
July
October
January
April
July
October
January
April
mg/LNO3-N100cmsoil
depth
Nitrate-N Concentrations: Row Crops
2014 2015 2016 2017
0
10
20
30
40
50
60
70
80
90
100
Nov.93
Feb.94
May.94
Aug.94
Nov.94
Feb.95
May.95
Aug.95
Nov.95
Feb.96
May.96
Aug.96
Nov.96
Feb.97
May.97
Aug.97
Nov.97
ppm(mg/L)NO3-N Nitrate-N Concentration in Groundwater Recharge: Row Crops
Row Crop #1
Row Crop #2
Row Crop #3
Row Crop #4
Row Crop #5
Row Crop #6
Corn: 195 - 213 kg N ha¯¹ Spring Green Beans: 135 kg N ha¯¹ Spring
Sugar Beets: 180 kg N ha¯¹ Spring
Squash: 146 kg N ha¯¹ May Spinach: 191 kg N ha¯¹
Sugar Beets: 168 kg N ha¯¹ Spring

16. 0
10
20
30
40
50
60
70
80
90
100
January
April
July
October
January
April
July
October
January
April
July
October
January
April
mg/LNO3-N100cmsoil
depth
Nitrate-N Concentrations: Grass Seed
2014 2015 2016 2017
0
10
20
30
40
50
60
70
80
90
100
Jan.94
Mar.94
May.94
Jul.94
Sep.94
Nov.94
Jan.95
Mar.95
May.95
Jul.95
Sep.95
Nov.95
Jan.96
Mar.96
May.96
Jul.96
Sep.96
Nov.96
ppm(mg/L)NO3-N Nitrate-N Concentration in Groundwater Recharge: Rye Grass Seed
Grass #1
Grass #2
PRG: 232 kg N ha¯¹
Nov, March & April
PRG: 177 kg N ha¯¹
Spring
TF: 200 kg N ha¯¹
Spring & Fall
ARG: 183 kg N ha¯¹
Spring & Fall

17. Past Present
•
•
• Pastpresent
Past Present
Peppermint
Row Crop
Grass Seed

18. • Agricultural practices in the valley have
become more nutrient efficient over time for
peppermint and row crops
• Grass seed fertilizer timing and rates should
be researched further to reduce nitrate
leaching
• Four years of data collection increases
reliability especially for perennial crops
• Frequent sharing of data with farmers
encourages community engagement
Conclusions