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Read about perennial ryegrass management strategies and techniques.

Perennial ryegrass management

In most southern Australian dairy farming environments, perennial ryegrass pastures can remain productive for at least four years. This significantly lowers the cost of production and, in a dryland environment, permits growth with minimal intervention as soon as soil moisture allows.

Key approaches to manage ryegrass pasture

  • Graze between the 2nd and 3rd leaf stage.
  • Maintain a constant cover of green leaf area all year.
  • Leave a post-grazing residual of 4-6 cm between clumps, equivalent to 1,500 to 1,600 kg DM per hectare.

Why graze ryegrass between 2nd and 3rd leaf stages?

Perennial ryegrass tillers normally maintain three live leaves.

After being grazed the three leaves are removed. When the 1st leaf emerges again it is produced using sugars stored in the residual stem.

As the 2nd leaf emerges, the plant will start restoring some of the sugar reserves that have been used.  The sugar reserves in the plant are fully restored once the 2nd leaf has completely emerged.

Grazing before the 2nd leaf has emerged will limit regrowth rates and threaten plant survival. Grazing after the 3rd leaf has fully emerged will waste pasture and reduce overall nutritional value. Cattle will reject more of this lower value pasture. The drop in nutrition after the 3rd leaf stage occurs faster in the warm seasons (spring-summer) than in winter.

Time your grazing to benefit root growth

The timing of grazing affects root growth. Immediately after a ryegrass tiller is grazed, the growth of the root stops so the plant can use its sugar reserves to grow new leaves. Once the 1st leaf emerges, the root growth will recommence.

Pastures that are grazed too frequently therefore have less root mass. Plants with less root mass are:

  • More easily pulled by cattle.
  • More vulnerable to hot and dry conditions.
  • More susceptible to root-damaging pests (like red-headed cockchafers).

More information

Perennial ryegrass management-grazing management to maximize growth and nutritive value (PDF, 1.1MB)

The 3030 Project reinforced three basic perennial ryegrass grazing management strategies.

  1. Graze between the 2nd and 3rd leaf stage or before canopy closure. 
  2. Leave a post-grazing residual of 4 - 6 cm between pasture clumps [equivalent to 1500 - 1600 kg DM per ha].
  3. Maintain a constant cover of green leaf area all year.

These guidelines are not an attempt to present a ˜silver bullet for perennial ryegrass pasture management. They are not meant to be exclusive; using other guidelines based on similar principles can also achieve success in maximising the growth of high quality pastures and minimising waste.

Perennial ryegrass management II - practical application of grazing principles (PDF, 1.1MB)

How to achieve the ABC targets in practice. There are four main areas of perennial ryegrass management that should be covered in order to achieve the ABC targets:

  1. Set rotation length in relation to Leaf Emergence Rate (LER) and monitor it.
  2. Choose the paddocks to be grazed and assess their pre-grazing cover.
  3. Adjust supplementation and/or close for conservation to achieve the target rotation length and post-grazing residuals.
  4. Make daily adjustments to the allocated grazing area in order to achieve the target pasture intake and post- grazing residuals.

Perennial ryegrass management IV -grazing management specific practices (PDF, 860KB)

This Information Sheet focuses on paddock-level specific grazing management practices. These practices should be understood within the context of the three basic strategies identified by the 3030 Project as the basis for pasture management (discussed in the grazing management to maximize growth and nutritive value Information Sheet).

Perennial ryegrass management VII - pasture renovation (PDF, 827KB)

Contents: Decision process leading to the renovation or over-sowing of perennial ryegrass pastures on southern Australian dairy farms. The focus of this factsheet is on:

  1. Monitoring and assessment of pasture stands.
  2. Decision criteria to choose renovation or an alternative.
  3. Oversowing.
  4. Full renovation.

Key points

  • Objective assessment of pasture leads to more informed decisions about renovation.
  • Decisions about pasture renovation should be based on recent paddock performance and the chance of the pasture recovering, taking into account the role of the pasture in the dairy system.
  • In Project 3030, oversowing perennial ryegrass with more perennial ryegrass was more successful than oversowing with Italian or hybrid ryegrass.
  • A full renovation program should not only take into account sowing the new grass but also address the temporary feed shortages that are caused by slow establishment of perennial pastures. Forage cropping may help to address this.

Major Initiatives

Focus Farms

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DairyBase is a web-based tool that enables dairy farmers to measure and compare their farm business performance over time.

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