Agricultural and Biosystems Engineering Publications

Campus Units

Agricultural and Biosystems Engineering, Civil, Construction and Environmental Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

2019

Journal or Book Title

Transactions of the ASABE

Volume

62

Issue

6

First Page

1607

Last Page

1617

Research Focus Area(s)

Land and Water Resources Engineering

DOI

10.13031/trans.13414

Abstract

The prairie pothole region ranges from central Iowa to the northwest into Montana and south-central Canada, totaling around 700,000 km2. This area contains millions of potholes, or enclosed topographical depressions, which often inundate with rainfall. Many are located in areas that have been converted to agricultural land through installation of artificial drainage. However, even with drainage, potholes pond or remain saturated during and after significant rain events. In this two-year study, surface water depth was collected hourly (typically from after planting through harvest) from eight farmed potholes (drained and under corn-soybean rotation) on the Des Moines Lobe in central Iowa. Nutrient data were collected daily and tested for nitrogen (N) and phosphorus (P) when inundation depth exceeded 10 cm. The data were analyzed in two ways. First, seasonal differences were investigated using samples from the first day of each inundation event. Surface water concentrations were higher in the early growing season than late season for total N (TN), NO3-N, NH3-N, total P (TP), and total suspended solids (TSS). Secondly, average event concentration changes were determined. Nitrate reductions occurred in 85% of multiday events, but these reductions were offset by increases in P. Total P and dissolved reactive P (DRP) had significant increases that averaged 0.51 and 0.46 mg L-1 per event, respectively, with event lengths of 2 to 19 days. This study demonstrates that inundated farmed potholes reduce NO3-N but serve as in-field hotspots, contributing elevated TP and DRP to drainage waters. When a surface intake directly connects inundated farmed potholes to drainage, new strategies, such as field management or engineered technologies, are needed to mitigate P export. This study is useful in informing policy regarding field management and conservation of farmed potholes.

Comments

This article is published as Martin, Alexander R., Michelle L. Soupir, and Amy L. Kaleita. "Seasonal and intra-event nutrient levels in farmed prairie potholes of the Des Moines Lobe." Transactions of the ASABE 62, no. 6 (2019): 1607-1617. DOI: 10.13031/trans.13414. Postged with permission.

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Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Copyright Owner

American Society of Agricultural and Biological Engineers

Language

en

File Format

application/pdf

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