Incidental nutrient transfers: assessing critical times in agricultural catchments using high-resolution data

Shore, Mairead and Jordan, Phil and Melland, Alice R. and Mellander, Per-Erik and McDonald, Noeleen and Shortle, Ger (2016) Incidental nutrient transfers: assessing critical times in agricultural catchments using high-resolution data. Science of the Total Environment, 553. pp. 404-415. ISSN 0048-9697

Abstract

Managing incidental losses associated with liquid slurry applications during closed periods has significant cost
and policy implications and the environmental data required to review such a measure are difficult to capture due to storm dependencies. Over four years (2010–2014) in five intensive agricultural catchments, this study used high-resolution total and total reactive phosphorus (TP and TRP), total oxidised nitrogen (TON) and suspended sediment (SS) concentrations with river discharge data to investigate the magnitude and timing of nutrient losses. A large dataset of storm events (defined as 90th percentile discharges), and associated flowweighted mean (FWM) nutrient concentrations and TP/SS ratios, was used to indicate when losses were indicative of residual or incidental nutrient transfers. The beginning of the slurry closed period was reflective of incidental and residual transfers with high storm FWM P (TP and TRP) concentrations, with some catchments also showing elevated storm TP:SS ratios. This pattern diminished at the end of the closed period in all catchments. Total oxidised N behaved similarly to P during storms in the poorly drained catchments and revealed a long lag time in other catchments. Low storm FWM P concentrations and TP:SS ratios during the weeks following the closed period suggests that nutrients eitherweren't applied during this time (best times chosen) or that they were applied to less risky areas (best places chosen). For other periods such as late autumn and duringwet summers,where storm FWMP concentrations and TP:SS ratios were high, it is recommended that an augmentation of farmer knowledge of soil drainage characteristics with local and detailed current and forecast soil moisture conditions will help to strengthen existing regulatory frameworks to avoid storm driven incidental nutrient transfers.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version cannot be displayed due to copyright restrictions.
Faculty / Department / School: Current - Institute for Agriculture and the Environment
Date Deposited: 09 Mar 2017 04:37
Last Modified: 09 Mar 2017 04:37
Uncontrolled Keywords: incidental nutrients; slurry; closed-period; catchments; water-quality
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: 10.1016/j.scitotenv.2016.02.085
URI: http://eprints.usq.edu.au/id/eprint/30825

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