Information

Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)

Description of study

What?

Thirty one plots ranging from 0.4 – 27ha, each with a particular soil, land use and land management combination, were instrumented to obtain hydrologic and runoff quality data.

When and Where?

The Pittsworth site was comprised of four nested plots. Details and locations for each nested plot are provided in Figure 1 and Table 2.

The remainder of the sites are also located within the Queensland Murray Darling Basin and represent the main soil types (basaltic derived cracking and non-cracking clays, grey clays supporting Brigalow, Acacia harpophylla, red brown earths supporting Poplar Box, Eucalyptus populnea, red earths growing Mulga, Acacia aneura, and solodics) and land management combinations (e.g. cultivation, pasture and forest).

How?

Data collected for each site included land use and land management practices, rainfall (intensity, depth) and runoff (quantity).  Runoff samples (using rising stage and pumping samplers and hand samples) were collected and stored at less than 4oC within 24 hours. All runoff samples were then held in acid-washed polyethylene bottles and frozen until analysed. Rainfall samples were collected from five of the sites across the region and treated similarly.

Samples were analysed at the Natural Resources Science Laboratory, Brisbane, for suspended sediment concentration (gravimetric) and for N and P levels in various forms (total P (TP), orthophosphate P (filterable reactive P, OP), total N (TN), Kjeldahl N (TKN), ammonia N (AN), and oxidised N (nitrite and nitrate, ON)) for both the dissolved state and attached to sediment (where sufficient sediment was available) – that is, unfiltered, filtered and filtrate as appropriate.

Analyses for TKN and TP were carried out using acid digests with automated colorimetric finishes. The TP finish for OP was based on ascorbic acid / phosphomolydic blue reaction.

The method for AN was based on the idophenol reaction. The method for ON was based on the Griess-Ilosvay reaction following Cadmium reduction. Analyses for AN, ON and OP broadly followed the automated continuous flow methods.

TN was determined as TKN plus ON for samples with suspended sediment concentrations less than 1 g/L otherwise as the sum of TKN filtrate, TKN filtered and ON filtrate.  Dissolved organic N was calculated as TKN (filtered) minus AN (filtered).

Particulate concentrations for the various parameters where suspended sediment concentrations were less than 1 g/L were calculated as the difference between paired filtered and unfiltered samples.

Project administration

Site identifier code: N/A

Principal investigator: Titmarsh G.

Principal data manager: N/A

Principal organizations: Murray-Darling Basin Commission and the National Resource Management Strategy

Data custodian: Queensland Department of Primary Industries

Key co-operators: N/A

Data access policy: Research has not been published and base data is not archived

Planned pathway for data: completed study, no evidence of formal database records.

Data warehousing: for ongoing studies N/A

Planned data upload frequency: for ongoing studies N/A

Key references and sources of this data synthesis

These data summaries have been extracted from:

  1. Titmarsh G, Cameron A, and Lock C. (2009). Nitrogen and phosphorous in runoff from small catchments in the Queensland Murray Darling Basin increases with intensity of catchment land use.

Keywords:

Nitrogen, phosphorous, runoff, land use

 

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