1. Iowa Agriculture Water Alliance
Farmer-led Efforts to Improve Water Quality
SD Corn Growers 30TH Annual Meeting
January 9th, 2016

2. Iowa Agriculture Water Alliance
Mission
Increase the pace and scale of farmer-led efforts to improve water quality
Founding organizations
Iowa Corn Growers Association
Iowa Pork Producers Association
Iowa Soybean Association

3. The scope of agricultural expansion is hard to describe just with words, so here are some maps. This is what the world looked like in 1700, with cropland shown as dark brown and rangelands shown in yellow. Forests are dark green and grasslands are lighter green.

4. At the turn of the last century, agriculture had expanded to cover much of the globe.

5. By 2050 many of our remaining intact natural areas are projected to be impacted by expanding agriculture.

6. Global Nitrogen, Phosphorus and Irrigation Use

7. Water Challenges – Global
Many of you will have heard about the dead zone in the Gulf of Mexico, which is caused by excess nutrients in our rivers, largely attributable to runoff of agricultural fertilizers. The fertilizers cause aglal blooms that, when they decompose, reduce the oxygen concentrations below what fish and other aquatic life can withstand, causing all life within the dead zone to flee or die. What you many not know is that this is one of dozens of locations around the world suffering from similar problems, primarily caused by agricultural runoff. Doubling our food production will require adding more fertilizers; this makes the challenge to keep those fertilizers on the farm fields instead of polluting our waters even more urgent.
Major known eutrophic and hypoxic areas. Reprinted from Selman et al.

8. U.S. Corn Production and Nutrient Use

9. Water Quality – National
>100,000 miles of rivers and streams
166 coastal hypoxic areas or “dead zones” nationwide
“nutrient pollution is widespread”: 27% river and stream miles have high N, 40% have high P
Stream biological condition:
55% poor, 23% fair;
(9% more “good” N condition, 19% fewer “good” P condition )
Source: 2013 EPA website: , ,

10. Water Quality – Regional Wadeable Streams with High Nutrients

11. USGS Estimates of Loss and Delivery of N and P to the Gulf
SPARROW - Modeled Estimate of N and P Discharge in Watersheds of the Mississippi R. Basin
<1
1 to 10
10 to 100
100 to 500
500 to 1000
>1000
<0.01
0.01 to 0.1
0.1 to 1.0
1.0 to 5.0
5.0 to 10.0
>10.0
kg km-2 yr-1
lbs/A/yr (approx.)
Alexander et al. Environ. Sci. Technol. 2008, 42, 822–830

12. USGS SPARROW Modeled Sources of Annual N Load to Gulf of Mexico
Robertson and Saad J. Environ. Qual. 42:1422–1440

13. USGS SPARROW Modeled Sources of Annual P Load to Gulf of Mexico
Robertson and Saad J. Environ. Qual. 42:1422–1440

14. EPA Hypoxia SAB report suggested 45% less total N AND 45% less total P
discharge to the Gulf to reduce hypoxia

15. Water Challenges – Regional
Mississippi River and Gulf of Mexico Hypoxia
Impact on the Gulf
David, et al., JEQ 39:

16. Iowa Water Challenges

17. Soils Vulnerable to Leaching
Nutrient content of water has more to do with historic changes in land use and hydrology than inputs by farmers.
Current major cropping system leaves soil vulnerable to erosion and nutrient leaching.
Markets and Technological Advances have shifted cropping patterns and increased productivity.
Have the most tools available to date and will still continue to develop and adopt new technologies
Past cropping system was driven by animal agriculture needed to power agriculture.

18. Changes in Land Use
Past cropping system was driven by animal agriculture needed to power agriculture.

19. Corn Nitrogen Cycling & Budget
Corn Grain Harvest
(~100 lbs N/acre/year)
Gaseous Loss
(~10 lbs N/acre/year)
Corn Nitrate Use
(~165 lb N/acre)
Corn Residue Return
(~65 lbs N/acre/year)
Fertilizer to Corn
(~150 lbs N/acre/year)
Microbial production of nitrate from native soil
( lbs N /acre/year)
NITRATE
Native Soil Organic Matter Nitrogen ~ 10,000 lb N/acre
Microbial re-uptake of nitrate
( lbs N/acre/year)
What leaches, what does not.
Nitrate leaching to water
(~30 lbs N/acre/year) 3

20. Soybean Nitrogen Cycling & Budget
Soybean Grain Harvest
(~165 lbs N/acre/year)
Atmospheric Fixation
(~100 lbs N/acre/year)
Soybean Nitrogen Use
(~230 lb N/acre)
Gaseous Loss
(~2 lbs N/acre/year)
Corn Residue Return
(~65 lbs N/acre/year)
Soybean Nitrate Use
(~130 lb N/acre/year)
Microbial production of nitrate from native soil
( lbs N /acre/year)
NITRATE
Native Soil Organic Matter Nitrogen ~ 10,000 lb N/acre
Microbial re-uptake of nitrate
( lbs N/acre/year)
What leaches, what does not.
Nitrate leaching to water
(~30 lbs N/acre/year) 4

21. Iowa Nutrient Reduction Strategy
Iowa Water Quality Initiative
IOWA DEPARTMENT OF AGRICULTURE & LAND STEWARDSHIP
Iowa Nutrient Reduction Strategy
Leads
Iowa Department of Ag and Land Stewardship
Iowa Department of Natural Resources
Iowa State University
Released May 2013, after public comment period
Living document meant to be adjusted as technologies are developed and understanding of these systems/practices improves.
Goal of 45% Reductions in Total Nitrogen and Phosphorous

22. Iowa Nutrient Reduction Strategy
Transformational change will be required to meet these targets, cost upwards of $4B
No single practice will meet these reductions
Current rate of adoption and investment – centuries; best case – decades
NRCS Photo

23. Iowa Agriculture Water Alliance
Conservation Practices
Cover Crops
Nutrient Management
Strip Till / No-Till
Bioreactors
Saturated Buffers
Nutrient Treatment Wetlands
Drainage Water Management
Buffers, Grass Waterways, Terraces, Prairie STRIPS
NRCS Photo
Implementation of The Iowa Nutrient Reduction Strategy is a central focus of our effort. Implementation means a farm by farm application of a suite of practices that will meet the goals of the strategy.
Many farmers are applying these practices, but we have a long way to go.
No single practice will achieve the goals of the strategy. Not all practices will work or are needed for every field. In many cases, application of multiple practices will be required.
This ISU document, which some of you may have seen, is an excellent brief summary of the practices included in the science assessment, along with an estimate of the average level of nutrient reduction that each individual practice is likely to achieve.

24. IAWA Engagement in Watershed Projects
Rock Creek
4 Mile Creek WMA
Walnut Creek WMA

25. Water Quality – Watershed Scale
First Draft Rock Creek Watershed Management Plan
Initial Estimated Costs
Initial Cost: $5.0m ($117/ac)
Yearly Cost: $750k ($45/ac)
*Update – after completion of watershed plan, Mitchell SWCD applied and received WPF/WSPF funding from IDALS. $174K/year one; $962K total request.

26. Iowa Agriculture Water Alliance
Questions?
Sean McMahon