Figure 27 : Small rock weirs ( PCDs ) after four wet seasons May 2022
• The ripping of part of Scald 1 did establish a level of persistent vegetation cover and this seemed a viable option for improving vegetation cover . Some soil amelioration would assist in stronger establishment of germinated seedlings .
• The trial of an ultra high density grazing treatment did not show improved land condition in comparison to other grazed areas .
• The condition of Scald 2 markedly improved during the project period with increased cover and encroachment of vegetation onto previously bare areas . Two “ biological carpeting ” treatments ( large numbers of cattle camped overnight ) were applied to the Scald exclosure of about 1ha but livestock were otherwise excluded from January 2018 to May 2022 . It is , therefore , difficult to separate any impact of the livestock treatments from the exclusion of livestock for long periods .
• DAF monitoring demonstrated the potential for significant improvement in biomass production with stock exclusion and also with planned grazing , even with pastures dominated by Indian couch . Biomass production of more than 5000kg / ha were recorded several times on monitored plots .
CONCLUSIONS :
• Diversion banks are a viable and relatively cost-effective option at that project scale ( 300m bank in length ) for reducing water flowing onto active head cuts . The spreader banks also worked well in slowing and spreading the outlet flow from the main bank . However , the long term viability of the banks could be an issue as they are susceptible to stock damage .
• Head cuts , the upper gully channels and the bare areas above the head cuts stabilised and had increased vegetation cover where the diversion bank reduced water flow . However , there was limited impact on erosion processes within the main gully complex .
• Head cuts continued to retreat where water was not removed from the system .
• Livestock exclusion and implementation of a planned grazing regime improved pasture biomass production and vegetation cover across nearly all sites but pasture composition remained relatively similar during the project period .
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