Understanding Nutrient Management Plans

Understanding Nutrient Management
Jim Vanden Brook
4th Annual Volunteer Stream Monitoring
Symposium
March 25, 2011

Why Should Water Quality Advocates Care about
Nutrient Management

Because Nutrient Management practices affect
much of our water:
Photos courtesy of USDA-NRCS

• In the Lake Mendota
Watershed, agricultural
lands produce 75% of
the phosphorus to Lake
Mendota
• Wisconsin has many
other primarily
agricultural watersheds
that show similar
impacts
• St. Croix Watershed
• Big Eau Pleine
• Can we change this
situation

Some Tentative Conclusions on Phosphorus
Load Reductions to Lake Mendota:
• Lake Mendota’s s water quality will improve relatively soon after
major reductions in P loads delivered to the lake
• P load reductions to Lake Mendota will produce measurable
water quality improvements in downstream lakes
• P load reductions will take a long time to occur without
large, drastic control measures because of high P conc. in
watershed soils. *
R.C. Lathrop & S.R. Carpenter, UW Environmental Forum, 23 Feb. 20102
* Targeted nutrient management on farms could reduce P
loading much more quickly and cheaply than “drastic” measures

Nutrient Management Planning:
Not Just How to Grow Crops
NRCS 590 standard defines
nutrient management
requirements to minimize
water quality impacts while
maximizing economic
return (Not(
Yield!!!)
Addresses chronic and
acute risks for delivery of
nutrients and sediment
SNAP Plus software
calculates risk of
phosphorus delivery
(P Index)

590 manure spreading restrictions
Frozen and snow covered
ground
• No spreading near lakes and
streams
• No spreading in high risk areas
• Limit liquid manure
applications
Fields close to surface water
• Limit liquid manure
applications

590 Restriction Map
• Available on-line
• Soil Map Units
• 2008 air photo
• Stream/Lake setbacks
• N restricted soils
• Winter restricted soils
• Improved markup
capability

Predicting Phosphorus Runoff:
THE WISCONSIN P INDEX
L. G. Bundy, L. Ward Good, and W.M. Jarrell
Dept. of Soil Science - University of Wisconsin-Madison
http://wpindex.soils.wisc.edu

P Index and Total Annual Runoff P
A tool for targeting and management
Total measured runoff P (lb/a/yr)
36
30
24
18
12
6
0
0 6 12 18 24 30
P Index value
Dr. Laura Ward Good UW Soil
Science

NM standard can reduce P loads
Soil Test P
High Soil P, Low P Index
P Index
Low Soil P, High P Index

P Index Distribution
In Pleasant Valley:
16% of acres yield 60% of P load
84%
7% 9%

Status of Nutrient Management Plans
Reported to DATCP - 2010
*
17% of WI
Crop acres
under NM
plan

Another Tool to Manage the
Risk of Runoff
Short term Runoff Prediction

Tools to assist Nutrient Management
Planning & Runoff Risk Prediction

Manure Advisory System – Part 2

March 17, 2011 Forecast

Nutrient Management practices can reduce risks
and protect water quality:
Photos courtesy of USDA-NRCS

AGRICULTURE, NUTRIENT MANAGEMENT, WATER QUALITY,
VICTORY!