Information

Soil Erosion Studies in the Mackay District

Level 1: General Description

Purpose:

This study increased the understanding of erosion processes and investigated ways of measuring erosion and applied these results in assessing the various factors contributing to erosion.

Methods (brief)

The first year of the study investigated various methods of measuring soil erosion over and expected range of conditions. The aim was to determine the reliability of the method and to isolate the largest areas of variation (areas of low and high soil loss).

The change in soil (erosion or accumulation) was measured by the means of a profilometer, which consists of pins dropped from a horizontal bar that is laid across the area of measurement.

The profile shape of the furrow was recorded and repeated along the furrow and monitored over the wet season. Changes in the profile (loss or accumulation) were recorded to determine soil erosion.

Key Findings

The result from the study found that soil texture is a major factor that affects soil erosion. Soil erosion from the Mulei was higher than from the other two sites even if the site was only conducted on an intermediate slope. The difference from Mulei and the other sites is the soil texture is fine to very fine sand to sandy loams, that can allow the transport of the soil material.

  • Soil movement ranged from 42.3 to 227 tonnes/ha.
  • Soil texture was important for the amount of soil being moved.
  • There is an increase in the soil texture for sites 1 to 3 ranging from heavy loam to sandy clay loam at site 3.
  • Slope effect is more evident during 1976 / 77 monitoring period. Sites 2 and 6 lost appreciably more soil than their paired lower slope sites 1 and 5.
  • Movement of soil down the slopes was a noticeable feature of both seasons.
  • Early in the season (periods 1 - 2) soil moved from the higher slope positions and deposited in the lower sections, the degree of this depends on the amount and intensity of rainfall.

 

Level 2, level 3, level 4 and level 5