Slope and contour bank prevalence on cropping land in the Fitzroy Basin

An analysis was undertaken to determine the occurrence of slope, and presence of contour banks on cropping land in the Fitzroy Basin (Central Queensland) to estimate how much cropping land occurs on slopes equal to or greater than 1%; and the proportion of that area where contour banks currently exist.

The analysis found overall, ~54% of all the cropping land ≥1% in the analysis area does not have contour banks present, but at a catchment scale the proportion varies substantially. Additionally, ~90% of all the cropping land on ≥1% slope without contour banks has a riverine fine sediment delivery ratio of 30% or less (a conceptual ratio between the volume of fine sediment entering an inland waterway verses the volume that arrives at the Great Barrier Reef lagoon).

These results can inform investment on the basis of area of most need, while the slope and fine sediment delivery ratio can be queried to inform or tailor investment priority setting and targeting within catchments. Potentially, investment in soil conservation on cropping land may be equally or more cost-effective as investment in other commodities and has the potential to also provide additional positive benefits to industry sustainability, food security, and riverine health. However, investment must also support and promote soil conservation knowledge and practices to ensure soil conservation measures, practices and existing contour banks and waterway structures (present on ~46% of all cropping land ≥1%) are correctly designed, fit for purpose, maintained, and functioning optimally.