P.PSH.2052 - Growing red meat productivity through the selection and establishment of perennial legumes

Summary

This project sought to address the low proportion of perennial legumes in rainfed red meat grazing systems in Tasmania and focused on two key production zones, the low-medium rainfall Midlands region and the high rainfall North-West region.

Pasture renovation and over-sowing experiments in the Midlands regions have provided key insights into how difficult it is to establish long-lived perennial plants in a seasonally moisture stressed environment. Whereas In the beef producing high rainfall North-west the focus was on improving the quality of winter wet pastures for beef production using waterlogging tolerant species. Strawberry clover remains the best available waterlogging tolerant option for high rainfall mixed pastures.

Objectives

The aim of the project was to evaluate methods for improved legume establishment in mixed pastures through novel sowing methods that advantage legumes in new and existing pastures. Another aim was to evaluate the waterlogging tolerance of perennial legumes with a particular focus on strawberry clover and Lotus species. In addition, establish a series of involve and partner demonstration sites that are informed by project learnings and assist in extending knowledge to producers in the North-west and Midlands regions.

Key findings

A range of methods are likely to be successful for establishing legumes in mixed swards, each with their own set of advantages and limitations. Much of the success of pasture establishment relates to seasonal conditions (soil moisture), though preparation remains the most controllable and often short-cutted phase of the pasture renovation. 

Over-sowing perennial legumes into existing swards is very challenging. Competition from the existing pasture is high. Greater success is likely to be found with annuals, which have greater seedling vigour. Long-term persistence will be more related to seed set rather than surviving in competition with existing pasture species through moisture deficits. Of the perennial legumes, red clover, being more vigorous as a seedling appears best adapted though it lacked persistence at the low rainfall site. 

Strawberry clover remains the best available waterlogging tolerant option for high rainfall mixed pastures. Feed quality analysis suggested that strawberry clover had consistently better dry matter digestibility and metabolisable energy than Lotus pedunculatus. The research suggests there is sufficient variability in strawberry clover germplasm to develop more productive cultivars without the risk of losing waterlogging tolerance. 

Involve and Partner sowings showed the benefits of; using crops for control of weeds before re-sowing; the difficulty of oversowing perennial legumes into grass dominant swards; the need to keep grass sowing rates low when combining with perennial legumes such as lucerne; the adaptability of strawberry clover in a range of mixes; the timing of autumn and spring sowing; and feed testing in order to prioritise feeding of livestock.

Benefits to industry

This project increased the focus on the importance of legumes in mixed sward pastures and motivations of producers to establish and manage pastures for legume production and persistence. The project increased awareness of appropriate sowing techniques for low-med rainfall environments, directly exposed 40 producers and service providers in each region by the presentation of project findings and other LPP projects and directly engaged 13 producers in 18 on-farm sowing activities. Presentations were given of experimental results and on farm demonstrations at Red Meat Updates (largest red meat producer conference in Tasmania) to over 350 producers and advisors in 2022 and 2025. 

On a technical note, project results offer an insight into the relative success of a number of sowing methods in establishing perennial pasture legumes. The trend towards a reduction in chemical use and cultivation provides limitations on existing methods for pasture renovation. Strip till offers a method of renovating pasture with minimal soil disturbance and no chemical use, though large changes in botanical composition with perennial plants is unlikely. Pasture renovations with multi-year clean up phase where weeds are controlled with the use of cereal and/or brassica crop phases are likely to assist legume establishment by reducing competition from broadleaf weeds that are difficult to control in pasture with selective herbicides.

MLA action

A producer extension guide (Optimising perennial pasture legumes) has now been published following the completion of the project and is available at: https://www.utas.edu.au/__data/assets/pdf_file/0011/1828442/Publication_Legumes-publication_2025.pdf

Future research

Dramatically changing species composition in existing pastures by oversowing without herbicide is very challenging. Further investigation to improve the placement of the seed in strip till machines may yield better results. Further exploration of strawberry clover germplasm, including within existing populations of cv. Palestine may yield more productive cultivars without losing waterlogging tolerance. Producers were most interested in building resilient pasture mixes and engaged well one on one with research teams and through the support of the involve and partner model with regular visits on farm and regular monitoring of newly sown pastures.