Rainfall Simulator Extension Tour: ‘Enderley’ Gindie

Level 1 General description

Purpose:

A rainfall simulator was used to examine the influence of different management options on infiltration of rainfall and runoff.

Methods (brief)

The soil present on site was a cracking clay scrub soil with a dry surface and minor cracks. Very light sunflower stubble on a lighter textured soil type was present at A and B while standing wheat stubble was present at C and D where the soil was a deeper cracking clay scrub soil (slope 0.5%).

The rainfall simulator was applied to the following four plots:

A) Sunflower stubble was 'cultivated' then 6 pits (4 per square meter) were created on the soil surface with a shovel to duplicate the effect of a pitting implement.  This treatment is referred to as Dimpled (cover 10%).

B) Similar to plot A but with no pits - Cultivated sunflower (cover 10%).

C) Soil was not disturbed and was similar to that after harvest. The plot is described as Zero-Till (cover 80%).

D) Was 'cultivated' bare with a shovel to create conditions similar to those left behind a scarifier.  The soil surface was furrowed, described as Scarified (cover 5%).

Key findings (brief)

• Cultivating soil which had cracks increased runoff compared to uncultivated soil.
• Stubble cover increases infiltration of intense rainfall.
• The simulations convincingly showed that a heavy storm will result in considerable runoff (and erosion) even though the soil is dry below the surface.
• Soils pits reduced runoff compared to bare soil but were not as effective as cover or cracks in improving infiltration.

Figure 1. Results of 75mm rain applied for 45 minutes at the rate of 100mm/hr (4”/hr) (Freebairn et al. 1992).

Location

‘Enderley’ - Gindie

Related studies

‘Orion Downs’ Orion; ‘Kurrajong’, Capella; ‘Maryland’, Retro; ‘Innesfree’, Wolfgang; ‘Tarvellon’, Kilcummin; ‘Bundella’ Wallumbilla; ‘Twin-Butts’ Wandoan; ‘The Limes’ Chinchilla; ‘Moruya’ Goondiwindi; ‘Forest Park’ Warwick

Key references and sources of this data synthesis

These data summaries have been extracted from:

1. Freebairn D, Wockner G, Huff S, Agnew J, Carroll C, Halpin M, Douglas N, Wade J. (1992). Rainfall simulator extension tour: central Queensland 27-29^th October 1992.