Information

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

Description of study

What?

8 pasture sites were examined to determine runoff and nutrient response to rainfall across 3 catchments (Figure 1).  

When and Where?

The Myall catchment encompasses 36,300ha and is dominated by pasture.

The region experiences ~1150mm of rainfall per annum, with slightly greater falls in the hinterland than on the coast. The topography of the region consists primarily of a wide coastal plain and a series of ridges and valleys of the eastern Great Dividing Range that rise to a maximum elevation of ~600 m.

Soils in the catchment are generally low in fertility and have developed from sedimentary rocks. Almost 50% of the catchment remains under native vegetation, primarily as dry sclerophyll forest.

How?

A rainfall simulator was used to generate runoff from pasture. The simulator consisted of 3 oscillating nozzles delivering water onto 2 simulation plots 2000 by 760 mm. At each site 2 rainfall simulations were conducted as close as possible to each other, generally within 10 m.

Ground cover at each site was estimated and the site was photographed. The local slope was recorded using an inclinometer placed on top of the simulation plot frames. Before each simulation, soil samples were taken for antecedent moisture conditions and sealed in metal tins. A core sampler was used to sample a core for the topsoil bulk density. Soil samples and cores were taken for future physical and chemical analysis.

The times that rainfall and runoff commenced were both recorded. Runoff was collected in five 1-L HDPE bottles; the first 2 bottles were collected consecutively as soon as runoff occurred, while the rest of the bottles were spaced as much as possible over the 1 h of simulated rainfall, but actual collection times varied.

A post simulation soil sample was collected from within the rainfall simulation plots and sealed in a metal tin. The second simulation was then run immediately adjacent to the first using the same procedure.

Project administration

Site identifier code: N/A

Principal investigator: Jones MG

Principal data manager: N/A

Principal organizations: NSW Department of Environment and Climate Change, Department of Environment and Heritage.

Data custodian: NSW Department of Environment and Climate Change

Key co-operators: Great Lakes Council

Data access policy: Research has been published but 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.  Jones MG, Vervoort RW, Cattle J. (2009). Nutrient losses under simulated rainfall from pasture plots in the Great Lakes District, New South Wales. Australian Journal of Soil Research  47: 555 – 564.

Keywords:

Rainfall simulation, grazing, diffuse pollution, water quality

 

Level 1, Level 3, Level 4 and Level 5