TREATMENTS AT LARGE-SCALE SITES
All large-scale sites were designed and supervised by engineers and revegetation specialists. The components of each large-scale site treatment is summarised in Table 2. The landholders had limited input during implementation, except for the construction of the fence. All sites had standard permanent fencing installed to enable grazing to be restricted. Four of the five sites had fencing immediately around the area of work, while the remaining site( Site 1) had fencing that included the adjacent riparian area and was thus a larger area.
The collated numbers of the erosion control structures and treatments implemented across the five large-scale sites are displayed in Figure 2. All of the catchments( pre-existing or created by reshaping) were treated with ameliorants / fertiliser and planted with pasture seed along the contour. Four of the five sites had the gullies reshaped, ameliorants of gypsum and some form of fertiliser / organic matter applied( e. g. granular fertiliser, mill mud, bagasse or hydro-mulching) and pasture seed sown( pasture mixtures including legume species). One site had four distinct rehab areas; therefore the total displayed in Figure 2 is seven. Sites 2, 3 and 4 employed water trucks to achieve ideal soil moisture for compaction while Site 1 compacted dry. Site 5 concentrated efforts on treating the catchment; the gullied area was not reshaped or treated intensively.
None of the large-scale sites used irrigation or planted woody stems. The many porous check dams installed were constructed of gabionsized rock and are mostly sited in the channels of reshaped gullies— typically about every 5m( horizontal distance)( refer to Figure 3). The bulk of these check dams are at Sites 2, 3 and 4. These totals include additions during maintenance work: one bund and three rock check dams across three sites.
Reshape, ameloriants, seed, irrigate 0
Reshape, gypsum, fertiliser 7
Reshape, fertiliser, seed Reshape, seed
0 0
Contour line rehab – catchment 3
Rock chute 12
Porus check dam / weirs 84
Bund 5
Bank and spreader – catchment 0
Cut off wall 6
Stickline
0
0 20 40 60 80 100
Figure 2. Total erosion control structures and treatments at the large-scale gully sites( from inital construction until December 2024).
NQ DRY TROPICS 9