SWPLG - Perennial pasture persistence

Summary

South West Prime Lamb Group is a farmer group situated in the high rainfall zone of far South West Victoria. Members are primarily specialist prime lamb producers running high stocking rate production systems based on perennial ryegrass (PRG) and clover pastures.

Whilst members have focussed on genetics and meat production, it has been an ongoing frustration that they have not been able to get PRG to persist in their pastures and find that when they try new expensive varieties that are supposed to persist, they tend to disappear faster than the older high endophyte varieties such as Victorian PRG.

The objectives of this project were to:

• Survey local producers to identify their pasture establishment and intervention practices for pasture persistence.
• Undertake an economic analysis to define the payback period for different pasture establishment and persistence methods.
• Evaluate four methods of pasture renovation and establishment through on-farm trialling.

From the survey of producers, it became evident that only one third were getting pastures to persist for more than the six years, which the economic analysis showed to be the breakeven year. Most used full renovation as part of a summer crop rotation and hadn't used winter cleaning or spray topping as an intervention method to extend the life of their pastures.

The economic analysis of pasture sowing options found that the longer a pasture persists at its peak production the more profitable is the initial investment. 

This project has shown that early intervention can improve the persistence of PRG in South West Victoria and that it is economic to do so. Interventions scenarios to extend the production peak had payback periods of two to four years and were much cheaper to implement than full pasture establishment scenarios. The most appropriate intervention would depend on the management of the farm, the extent and type of weed infestation and seasonal conditions.

All interventions for managing barley grass, silver grass and strategic spelling to improve PRG content had a positive annuity per ha at a base discount rate of 8% ranging from $35 to $137 depending on the intervention thus demonstrating that all interventions were worth implementing.  In general, two consecutive years of chemical intervention was more effective than one.

This project received additional collaborative support from Agriculture Victoria, allowing the group to increase the scope of the research undertaken.