- Title
- Nitrate import-export dynamics in groundwater interacting with surface-water in a wet-tropical environment
- Creator
- Rasiah, Velu; Armour, John; Cogle, A.L.; Florentine, Singarayer
- Date
- 2010
- Type
- Text; Journal article
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/57957
- Identifier
- vital:3261
- Identifier
-
https://doi.org/10.1071/SR09120
- Identifier
- ISSN:0004-9573
- Abstract
- Solute import-export dynamics in groundwater (GW) systems interacting with surface-water are complex, particularly under farming systems receiving high fertiliser/pesticide inputs in high rainfall regions. We investigated whether any linkage existed between nitrate-N in: (i) leachate (LC) collected at similar to 1m depth under banana (Musa) and that in GW, and (ii) GW and drain-water (DW). We also assessed the hazard/risk of the concentrations against the trigger values proposed for the sustainable health of different aquatic ecosystems. The LC, GW, and DW samples were collected at short intervals during 3 consecutive rainy seasons (January-July) from a similar to 300-ha banana farm in the wet tropical Tully River Catchment in north-east Queensland, Australia. Water samples were analysed for nitrate-N, dissolved organic carbon, and electrical conductivity. The coefficients of variation, ranging from 13 to 132%, obtained for solute concentrations in LC, GW, and DW indicated large within-and between-season temporal variations. The mean nitrate-N concentrations in LC, GW, and DW were 5320, 4135, and 1976 mu g/L, respectively, and were orders of magnitude higher than the trigger values proposed for the sustainable health of most of the neighbouring aquatic ecosystems. Significant positive associations, with correlation coefficients ranging from 0.56 to 0.96, existed between rainfall received and LC volume collected, and between LC volume and solute concentration, including nitrate-N, in the LC. Similar associations existed between the solutes in (i) LC and GW and (ii) GW and DW. From these associations we conclude the unused/under-utilised nitrate that leached below the root-zone was imported into the GW by the percolating rainwater and was exported into the drain via GW base-flow discharge.
- Publisher
- CSIRO
- Relation
- Australian Journal of Soil Research Vol. 48, no. 4 (2010), p. 361-370
- Rights
- Copyright CSIRO
- Rights
- Open Access
- Rights
- This metadata is freely available under a CCO license
- Subject
- 05 Environmental Sciences; 07 Agricultural and Veterinary Sciences; 06 Biological Sciences; Nitrate; Leachate; Groundwater; Drain-water; Three-way linkage; Trigger values
- Full Text
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