Timing of riverine export of nitrate and phosphorus from agricultural watersheds in Illinois: Implications for reducing nutrient loading to the Mississippi River

Todd V. Royer, Mark B. David, Lowell E. Gentry

Research output: Contribution to journalArticle

Abstract

Agricultural watersheds in the upper Midwest are the major source of nutrients to the Mississippi River and Gulf of Mexico, but temporal patterns in nutrient export and the role of hydrology in controlling export remain unclear. Here we report on NO3--N, dissolved reactive phosphorus (DRP), and total P export from three watersheds in Illinois during the past 8-12 years. Our program of intensive, long-term monitoring allowed us to assess how nutrient export was distributed across the range of discharge that occurred at each site and to examine mechanistic differences between NO3 --N and DRP export from the watersheds. Last, we used simple simulations to evaluate how nutrient load reductions might affect NO 3--N and P export to the Mississippi River from the Illinois watersheds. Artificial drainage through under-field tiles was the primary mechanism for NO3--N export from the watersheds. Tile drainage and overland flow contributed to DRP export, whereas export of particulate P was almost exclusively from overland flow. The analyses revealed that nearly all nutrient export occurred when discharge was ≥ median discharge, and extreme discharges (≥ 90th percentile) were responsible for >50% of the NO3--N export and >80% of the P export. Additionally, the export occurred annually during a period beginning in mid-January and continuing through June. These patterns characterized all sites, which spanned a 4-fold range in watershed area. The simulations showed that reducing in-stream nutrient loads by as much as 50% during periods of low discharge would not affect annual nutrient export from the watersheds.

Original languageEnglish (US)
Pages (from-to)4126-4131
Number of pages6
JournalEnvironmental Science and Technology
Volume40
Issue number13
DOIs
StatePublished - Jul 1 2006

Fingerprint

Watersheds
Nutrients
watershed
nutrient
Phosphorus
Rivers
Butyrophenones
phosphorus
Tile
Drainage
Custodial Care
Cosyntropin
river
overland flow
drainage
simulation
Hydrology
Nitrates
Monitoring
Antimony Potassium Tartrate

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Science(all)
  • Environmental Chemistry

Cite this

@article{4469ddb082c24e21889bfa2b0276e5f7,
title = "Timing of riverine export of nitrate and phosphorus from agricultural watersheds in Illinois: Implications for reducing nutrient loading to the Mississippi River",
abstract = "Agricultural watersheds in the upper Midwest are the major source of nutrients to the Mississippi River and Gulf of Mexico, but temporal patterns in nutrient export and the role of hydrology in controlling export remain unclear. Here we report on NO3--N, dissolved reactive phosphorus (DRP), and total P export from three watersheds in Illinois during the past 8-12 years. Our program of intensive, long-term monitoring allowed us to assess how nutrient export was distributed across the range of discharge that occurred at each site and to examine mechanistic differences between NO3 --N and DRP export from the watersheds. Last, we used simple simulations to evaluate how nutrient load reductions might affect NO 3--N and P export to the Mississippi River from the Illinois watersheds. Artificial drainage through under-field tiles was the primary mechanism for NO3--N export from the watersheds. Tile drainage and overland flow contributed to DRP export, whereas export of particulate P was almost exclusively from overland flow. The analyses revealed that nearly all nutrient export occurred when discharge was ≥ median discharge, and extreme discharges (≥ 90th percentile) were responsible for >50% of the NO3--N export and >80% of the P export. Additionally, the export occurred annually during a period beginning in mid-January and continuing through June. These patterns characterized all sites, which spanned a 4-fold range in watershed area. The simulations showed that reducing in-stream nutrient loads by as much as 50% during periods of low discharge would not affect annual nutrient export from the watersheds.",
author = "Royer, {Todd V.} and David, {Mark B.} and Gentry, {Lowell E.}",
year = "2006",
month = "7",
doi = "10.1021/es052573n",
volume = "40",
pages = "4126--4131",
journal = "Environmental Science and Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "13",

}

TY - JOUR

T1 - Timing of riverine export of nitrate and phosphorus from agricultural watersheds in Illinois

T2 - Environmental Science and Technology

AU - Royer,Todd V.

AU - David,Mark B.

AU - Gentry,Lowell E.

PY - 2006/7/1

Y1 - 2006/7/1

N2 - Agricultural watersheds in the upper Midwest are the major source of nutrients to the Mississippi River and Gulf of Mexico, but temporal patterns in nutrient export and the role of hydrology in controlling export remain unclear. Here we report on NO3--N, dissolved reactive phosphorus (DRP), and total P export from three watersheds in Illinois during the past 8-12 years. Our program of intensive, long-term monitoring allowed us to assess how nutrient export was distributed across the range of discharge that occurred at each site and to examine mechanistic differences between NO3 --N and DRP export from the watersheds. Last, we used simple simulations to evaluate how nutrient load reductions might affect NO 3--N and P export to the Mississippi River from the Illinois watersheds. Artificial drainage through under-field tiles was the primary mechanism for NO3--N export from the watersheds. Tile drainage and overland flow contributed to DRP export, whereas export of particulate P was almost exclusively from overland flow. The analyses revealed that nearly all nutrient export occurred when discharge was ≥ median discharge, and extreme discharges (≥ 90th percentile) were responsible for >50% of the NO3--N export and >80% of the P export. Additionally, the export occurred annually during a period beginning in mid-January and continuing through June. These patterns characterized all sites, which spanned a 4-fold range in watershed area. The simulations showed that reducing in-stream nutrient loads by as much as 50% during periods of low discharge would not affect annual nutrient export from the watersheds.

AB - Agricultural watersheds in the upper Midwest are the major source of nutrients to the Mississippi River and Gulf of Mexico, but temporal patterns in nutrient export and the role of hydrology in controlling export remain unclear. Here we report on NO3--N, dissolved reactive phosphorus (DRP), and total P export from three watersheds in Illinois during the past 8-12 years. Our program of intensive, long-term monitoring allowed us to assess how nutrient export was distributed across the range of discharge that occurred at each site and to examine mechanistic differences between NO3 --N and DRP export from the watersheds. Last, we used simple simulations to evaluate how nutrient load reductions might affect NO 3--N and P export to the Mississippi River from the Illinois watersheds. Artificial drainage through under-field tiles was the primary mechanism for NO3--N export from the watersheds. Tile drainage and overland flow contributed to DRP export, whereas export of particulate P was almost exclusively from overland flow. The analyses revealed that nearly all nutrient export occurred when discharge was ≥ median discharge, and extreme discharges (≥ 90th percentile) were responsible for >50% of the NO3--N export and >80% of the P export. Additionally, the export occurred annually during a period beginning in mid-January and continuing through June. These patterns characterized all sites, which spanned a 4-fold range in watershed area. The simulations showed that reducing in-stream nutrient loads by as much as 50% during periods of low discharge would not affect annual nutrient export from the watersheds.

UR - http://www.scopus.com/inward/record.url?scp=33746774712&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33746774712&partnerID=8YFLogxK

U2 - 10.1021/es052573n

DO - 10.1021/es052573n

M3 - Article

VL - 40

SP - 4126

EP - 4131

JO - Environmental Science and Technology

JF - Environmental Science and Technology

SN - 0013-936X

IS - 13

ER -