Journal article
Nitrogen and phosphorus budgets for the sub-tropical Richmond River catchment, Australia
Biogeochemistry, Vol.50, pp.207-239
2000
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Abstract
<p>Nitrogen and phosphorus budgets were developed for four sub-catchments in the Richmond River catchment for two study years. The catchment is used for a variety of farming pursuits including dairying, beef,cropping, fruit, nuts, forestry, and sugar cane. Each sub-catchment varies in hydrology, the proportion ofeach land use, and the population density which enabled a unique opportunity to study fluxes and storage associated with a variety of environmental factors. Total loadings entering each sub-catchment varied from 12 to 57 kg ha<sup>–1</sup>yr<sup>–1</sup> for nitrogen and 0.25 to 6.6 kg ha<sup>–1</sup>yr<sup>–1</sup> for phosphorus with little inter-annual variation. Averaged across the whole catchment, nitrogen fixation (47%) dominated the inputs; fertiliser (26%) and rainfall (21%) made up the next largest inputs. Fertiliser inputs dominated the phosphorus budget(65.5%); rainfall and manures making up 13% and 12%respectively. Produce dominated the outputs of both nitrogen and phosphorus from the four sub-catchments being greater than the riverine export. The delivery of nitrogen to catchment streams ranged from <1>to24% of the total inputs and the delivery of phosphorus to catchment streams ranged from <1 to>39%. Storage of phosphorus in catchment soils varied between –0.32 and 4.46 kg ha<sup>–1</sup>yr<sup>–1</sup>. When denitrification and volatilisation were estimated using data from other studies, storage of nitrogen ranged from 1 to 24 kg ha<sup>–1</sup>yr<sup>–1</sup>. Despite the episodic nature of run off in the sub-tropical Richmond River catchment, the magnitude of nutrient fluxes and storage appear similar to other catchments of the world which have mixed land use and relatively low catchment nutrient loadings.</p>
Details
- Title
- Nitrogen and phosphorus budgets for the sub-tropical Richmond River catchment, Australia
- Creators
- Lester J McKee - San Francisco Estuary InstituteBradley D Eyre - Southern Cross University
- Publication Details
- Biogeochemistry, Vol.50, pp.207-239
- Identifiers
- 1426; 991012820524502368
- Academic Unit
- Centre for Coastal Biogeochemistry; School of Environment, Science and Engineering; Faculty of Science and Engineering; Science
- Resource Type
- Journal article