costs , for example ), many more sites can potentially be remediated in this way .
• Water diversion banks are a successful and , historically , a soil conservation approach to gully management . A number of designs were used in the project and in general the works operated as designed . There are on-going maintenance considerations for this approach and the cost-benefit ratios need to be carefully considered for each site . Lower risk structures can also be designed in-house and become more cost effective .
• After four wet seasons , the Strathalbyn , rock-capped , alluvial gully site appears to be a successful and cost-effective , long-term remediation project . However , where other sites generated less sediment yield e . g . Strathalbyn Dunn ’ s paddock and the Johnnycake sites , or suitable rock was no longer available e . g . the Strathalbyn alluvial control gully , the implemented remediation techniques were less successful .
Consensus around the main grazing management principles ( planned grazing ) to emerge from the Stomping out Sediment project , and the actual practices being implemented across project sites , converged on the following :
• Increasing the distribution of watering points , in conjunction with sub-division of smaller paddocks around each watering point .
• Planned ( short duration ) rotation of cattle mobs . Size of mobs and duration of graze in each paddock needs to be based on forage budgeting and pasture “ rest ” ( or recovery ) periods which are much longer than a 1-2 month wet season spell .
• Retaining sufficient ground cover and pasture integrity to allow triggering of ongoing growth cycles e . g . through repeated short duration grazes .
In the application of these principles , the project enabled the subdivision of 14 paddocks , and associated water point distribution , across about 1200ha for improved grazing practices , generally planned grazing practices . In addition , smaller paddocks were created for specific purposes e . g . ultra high density or biological carpeting livestock impact or for comparative livestock ( and marsupial ) exclusion . The grazing principles were applied across most of the project sites and in a range of environments , and were also compared with livestock exclusion , over three or more wet seasons , on a number of the sites .
• An initial period of livestock exclusion ( at least one full wet season and sometimes a 12 month period or more ) at most sites resulted in marked improvement in plant biomass , cover , vigour and diversity .
• Except on exposed earthworks , there was limited benefit observed from ripping ( or other surface disturbance ) and re-seeding , while broadcasting of seed , even on sites with limited ground cover , also produced limited establishment and survival of pasture grasses .
• Across all sites , there was limited evidence that the planned grazing practices ( rotational , high or ultra high density ) accelerated land condition improvement during the project .
• There was strong evidence that livestock exclusion and planned grazing practices , in the project timeframes , resulted in increased plant biomass , generally , a slow increase in land condition and , at many project sites , an improvement in gully profiles and channel stability , particularly where water was removed from the gullies by mechanical intervention .
• At sites monitored by DAF , Landscape Function Analysis indicated that nutrient loss and nutrient capture , and infiltration indices were stable , or showed a slight improvement on one severely degraded site across three or four wet seasons .
• In landscapes with poor land condition , and particularly when dominated by Indian couch , measured land condition was sensitive to seasonal conditions .
13