Journal article
Total phosphorus export from Iowa agricultural watersheds: Quantifying the scope and scale of a regional condition
Journal of hydrology (Amsterdam), Vol.581, p.124397
02/2020
DOI: 10.1016/j.jhydrol.2019.124397
Abstract
•Annual TP yields from 46 Iowa watersheds were estimated for the period from 2000 to 2017.•Annual mean yields ranged from 0.44 to 7.71 kg/ha.•TP yields were positively correlated to precipitation, basin slope and stormflow.•Iowa’s TP export contributes 15% of the TP load to the Gulf of Mexico.
Total phosphorus (TP) export in rivers contributes to development of hypoxic conditions in receiving waterbodies and is typically sourced to agricultural nonpoint sources. Systematic quantification of TP loads and yields at a regional scale is not often reported but TP yields are known to vary considerably. In this study, TP yields from 46 Iowa watersheds were evaluated for the period from 2000 to 2017 to evaluate long-term patterns of TP export and quantify the contribution of Iowa-sourced TP loads to the Gulf of Mexico. Using two common load estimation programs, annual mean and median TP yields ranged from 0.44 to 7.71 kg/ha and 0.32 to 3.75 kg/ha, respectively. Highest median yields were found in western and southern Iowa. The weighted average TP yield for Iowa was 1.70 kg/ha and, on average, Iowa’s TP export contributes approximately 15% of the TP load to the Gulf of Mexico. Reducing TP export will require improved quantification and differentiation of sources of TP loads in Midwestern rivers and a commitment to find strategies that reduce both TP and NO3-N loss from agricultural lands in a complementary and additive approach.
Details
- Title: Subtitle
- Total phosphorus export from Iowa agricultural watersheds: Quantifying the scope and scale of a regional condition
- Creators
- Keith E Schilling - Iowa Geological Survey, University of Iowa, Iowa City, IA, United StatesMatthew T Streeter - Iowa Geological Survey, University of Iowa, Iowa City, IA, United StatesAnthony Seeman - Iowa Soybean Association, Ankeny, IA, United StatesChristopher S Jones - IIHR Hydroscience and Engineering, University of Iowa, Iowa City, IA, United StatesCalvin F Wolter - Iowa Department of Natural Resources, Des Moines, IA, United States
- Resource Type
- Journal article
- Publication Details
- Journal of hydrology (Amsterdam), Vol.581, p.124397
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.jhydrol.2019.124397
- ISSN
- 0022-1694
- eISSN
- 1879-2707
- Language
- English
- Date published
- 02/2020
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984066335802771
Metrics
15 Record Views