Flow paths and phosphorus transfer pathways in two agricultural streams with contrasting flow controls

Mellander, Per-Erik and Jordan, Phil and Shore, Mairead and Melland, Alice R. and Shortle, Ger (2015) Flow paths and phosphorus transfer pathways in two agricultural streams with contrasting flow controls. Hydrological Processes, 29 (16). pp. 3504-3518. ISSN 0885-6087

Abstract

In this paper, we analyse 4 years of data from simultaneous high-frequency monitoring of streamflow and phosphorus (P) concentration. This was carried out to investigate hydrological flow paths and P transfer pathways from diffuse sources in two intensively farmed river catchments (~10 km2) with contrasting flow controls and dominating flow paths. Catchment scale P loss was viewed on an annual and event flow basis and related to hydrological flow paths. A grassland catchment with mostly poorly drained soils, and a higher Q10:Q90 ratio (60 compared with 24), had three times higher annual P loss than an arable catchment with mostly well-drained soils (1.04 compared with 0.34 kg TPha-1) despite the arable catchment having larger areas with high soil P status and more discharge. Neither of the catchments indicated supply limitations. The magnitude of the P losses from the two catchments was not defined by land use, source pressure or discharge volume but rather by more basic rainfall-to-runoff partitioning influences that determine proportions of quickflow and slowflow. There were larger differences between the years than between the catchments, and the P loss of the arable catchment appeared more sensitive to climate. The results confirmed the need to manage the quickflow components of runoff to moderate P transfers. Therefore, in order to further reduce diffuse pollution it may be necessary to account for the contrast in hydrological function before or in addition to any of the other factors known to influence P losses from catchments (such as soil P and land use). Schemes designed to attenuate diffuse P after mobilization from soil surfaces can then be targeted (and resourced) more effectively.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: Current - Institute for Agriculture and the Environment
Date Deposited: 04 Apr 2017 06:42
Last Modified: 11 Sep 2017 06:01
Uncontrolled Keywords: diffuse pollution; agriculture; eutrophication; high-frequency water quality monitoring; nutrient management; climate
Fields of Research : 07 Agricultural and Veterinary Sciences > 0799 Other Agricultural and Veterinary Sciences > 079901 Agricultural Hydrology (Drainage, Flooding, Irrigation, Quality, etc.)
07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070101 Agricultural Land Management
05 Environmental Sciences > 0502 Environmental Science and Management > 050206 Environmental Monitoring
Socio-Economic Objective: D Environment > 96 Environment > 9609 Land and Water Management > 960905 Farmland, Arable Cropland and Permanent Cropland Water Management
D Environment > 96 Environment > 9614 Soils > 961402 Farmland, Arable Cropland and Permanent Cropland Soils
D Environment > 96 Environment > 9606 Environmental and Natural Resource Evaluation > 960608 Rural Water Evaluation (incl. Water Quality)
Identification Number or DOI: 10.1002/hyp.10415
URI: http://eprints.usq.edu.au/id/eprint/30870

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