Journal article
Relating carbon and nitrogen transport from constructed farm drainage
Agricultural water management, Vol.213, pp.12-23
03/01/2019
DOI: 10.1016/j.agwat.2018.10.004
Abstract
•Export of carbon through constructed drainage systems is small relative to soil organic matter stores.•Levels of inorganic carbon far exceed those of organic carbon in drainage water.•Loss of nitrate-nitrogen from constructed drainage is more transport limited compared to both inorganic and organic carbon.
Fertility and crop production in soils of the recently-glaciated agricultural Midwestern U.S. link to soil inorganic and organic carbon, soil nitrogen and nitrogen inputs. Research relating transport of each to the others through the constructed drainage network to receiving streams is sparse. The main objective of this work was to quantify and characterize concentrations and yields of inorganic and organic carbon (IC and OC) along with nitrate-nitrogen (NO3-N) using a four-year dataset that included discharge from two managed drainage districts in the Cornbelt state of Iowa. Our analysis shows loss of carbon through these constructed drainage networks averages 124 kg ha−1 yr−1 with more than 90% of this total in carbonate form and only 7% in organic forms, a small amount relative to soil organic stores. Transport of NO3-N can total as much as 97 kg ha−1 yr−1. Although loads of IC, OC and NO3-N all vary similarly with discharge, NO3-N is especially transport-limited. Elevated OC concentrations in March are likely linked to recent manure application to soil surfaces, with concentrations returning to a consistent baseline thereafter. Concentrations of IC are lowest at high flows, indicating dilution by fresh water from recent hydrologic events into the drainage system which disproportionately mobilize NO3-N compared to IC. Although yields of IC and OC to the drainage system indicate tile drainage does not threaten to deplete soil organic matter stores, returning the system to a condition where carbon and nitrogen cycle together could improve stream water quality.
Details
- Title: Subtitle
- Relating carbon and nitrogen transport from constructed farm drainage
- Creators
- Christopher S. Jones - IIHR-Hydroscience and Engineering, University of Iowa, 100 C. Stanley Maxwell Hydraulics Laboratory, Iowa City, Iowa, 52242, USAKeith E. Schilling - United States Geological SurveyAnthony Seeman - Iowa Soybean Association
- Resource Type
- Journal article
- Publication Details
- Agricultural water management, Vol.213, pp.12-23
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.agwat.2018.10.004
- ISSN
- 0378-3774
- eISSN
- 1873-2283
- Grant note
- name: Iowa Nutrient Research Center
- Language
- English
- Date published
- 03/01/2019
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984383890102771
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