USDA/ARS National Soil Tilth Laboratory 2004

Gulf Hypoxia Goals

Reduce average to 5000 km2 by 2015• 2001 Hypoxia Action Plan - 30% N

reduction target• Updated Gulf Science – 35-45%, up to

55% & 60% N reduction, P reduction• SAB report 8/27/07 – at least 45%

reductions of both N and P

2001-2005 Nitrogen Loadings to the Gulf

32% N reduction – “previous” regression method for USGS monitoring data

21% N loading reduction – “new” regression method for USGS monitoring data

No corresponding change in size of zone

Role of fertility management to reduce N transport to water resources and to meet Gulf hypoxia N reduction targets?

Impact of annually increasing corn yields with steady fertilizer rates?

Excess nutrients?

Iowa’s Statewide Nutrient BudgetNitrogen Balance

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

N Inputs N Outputs

Tons

Iowa Statewide Hypoxia Strategy Dean’s 10/15/07 Strawman

N Reduction Target 45%, at least

Improved fertility mgmt 10%Riparian buffers <1%Drainage management ??Not discovered practices ??Row crop land retirement ??N sink wetlands 30+%

Needed “Scaling” of N Sink WetlandDeployment

• Current Iowa CREP – 20 sites/year

• Adoption level to achieve 40-50% reduction of statewide NO3 transport to water resources for Gulf hypoxia goal

3,000 – 10,000 N sink wetland sites in Iowa

10,000 sites478 sites

1999 2000 2001 2002 2003 2004 2005 2006 2007

CREP Sign

ing Cere

mony at

Iowa S

tate Fair

CREP discuss

ion initia

ted with

FSA

2000 Io

wa legisla

ture

pass

water in

itiativ

e –

includes C

REP

SFY2001 $3,000,00

0 appropria

tion

SFY2001 ($

2,990,583)

de-ap

propria

tion

SFY2002

$3,000

,000 a

ppropria

tion

SFY2002 ($

2,965,465)

de-ap

propria

tion

Region

al Perm

it #34 i

ssued

First s

ites a

pprove

d

through R

egiona

l

Permit #

34CREP Engin

eering o

utsou

rced

NRCS desig

ns firs

t 6 si

tes under N

WP 27

Individ

ual 404

permits

requir

ed & in

itiate

progra

mmatic ag

reemen

ts for

RP

20 C

REP wetla

nd proj

ects

cons

tructe

d to date

– 6

unde

r NWP 27

, 14 un

der

indivi

dual

404 perm

its

Dedica

ted C

REP Field/

Lando

wner Conta

ct Supp

ort

1993 – 2007 IDALS Funding of N

-sink

wetland re

search

, ISU

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

CR

EP

P

rogr

ess

Deappropriation

RegulatoryE

conomics

?