Rainfall Simulator Extension Tour: ‘Moruya’ Goondiwindi

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)

Soil present on site was a red-brown earth. The surface was moist with no surface cracks.

The rainfall simulator was applied to the following four plots:

A) Cultivated/dimpled. The soil was ‘cultivated’ then 6 pits (4/m²) were created on the soil surface with a shovel to duplicate the effect of a pitting implement (cover 5%).

B) Cultivated / furrowed. The soil was ‘cultivated’ with a shovel to create conditions similar to those left behind a scarifier (cover 5%).

C) No-till / high cover. The soil was not disturbed since wheat harvest, with rain having closed any soil cracks which may have been present (cover 80%).

D) No-till / bare. Similar to C but with stubble removed to simulate grazed stubble (cover 5%).

Key findings (brief)

• Runoff began soon after rainfall commenced on uncultivated soil. Two thirds of rainfall was lost as runoff (Figure 1); and
• Cultivation increased infiltration dramatically, and soil pits were useful in improving infiltration.

Location

‘Moruya’ Goondiwindi

Related studies

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

Key references and sources of this data synthesis

These data summaries have been extracted from:

1. Cawley ST, Hamilton NA, Freebairn DM, Markey LJ. Viable Farming Systems Group Project: Evaluating fallow management options by using rainfall simulation. Queensland Department of Primary Industries October 1992