Prairie grass

NOTE: The information in this Agnote must be read in conjunction with Introduction to selecting and using pastures in NSW, which covers information on areas of adaptation, sources of variability, species mixtures, and important issues related to animal health and the conservation of native vegetation.
Pasture type and use Annual to short-term perennial grass. Pasture life can be extended by good management.
Area of adaptation Coast, Hunter, tablelands and irrigation areas.
Min. average annual rainfall 850 mm
Advantages
  • Provides quality feed in late summer / autumn and late winter / early spring.
  • Similar growth habit to perennial ryegrass, but grows more into summer and is more heat-tolerant.
  • Ability to recover from hard grazing.
  • Stock prefer it at all stages of growth compared with perennial ryegrass.
  • Combines with most legumes, but best with red and white clover in pure swards with legumes or in mixtures with other grasses.
  • Persistent in dry conditions.
  • Palatability is good, even at seed-set.
  • Can be used as a permanent pasture if well managed.
Disadvantages
  • Requires strict rotational grazing to ensure persistence.
  • Feed quality similar to that of annual ryegrass.
  • Has low level of magnesium and iodine, which can be overcome by inclusion of legumes in the pasture, or supplement stock if grazed on this type of pasture for prolonged periods.
Soil requirements Requires highly fertile well-drained soils, with best growth on soils with pH(Ca) 5.5 or above. Performs poorly on waterlogged soils. Responds well to nitrogen fertiliser for best yields.
Varieties Grasslands Matua
Atom
Tango
Sowing rate - in mixtures Up to 7 kg/ha in mixtures with other perennial grasses, but can be better managed as pure swards.
20–30 kg/ha in intensive swards with legumes. This should be increased to 40–60 kg/ha with white clover added for high rainfall or irrigated pastures, where financial returns are expected to be high.
Sowing time Early autumn
Companion species Can be included with most pasture grasses and legumes, but because of lax rotational grazing requirements, is best sown as the only grass in mix with legumes.
Inoculation N/A
Major nutrient deficiencies Nitrogen, phosphorus and sulfur; possibly potassium and other site-specific nutrients as required.
Main insect pests Army worm
Main diseases Head smut (Ustilago bullata) — for control, treat seed with a registered seed dressing prior to sowing.
Management Where intensive grazing management is possible, follow these guidelines:

From sowing, graze at a time equivalent to reach 3–4 new leaves/tiller, which will be 30–35 days in mid-winter to 20–22 days in spring. However, this may be compromised by soil moisture, as it seems critical not to graze when the soil is waterlogged.

There appears to be no advantage in deferring grazing in early autumn to allow the new prairie grass seedlings to establish. In fact, if there are weeds present, the effect of deferment from grazing is negative on prairie grass production.

If invasion by summer grasses becomes significant, spray out whole pasture with herbicide (rate and herbicide type depends on weeds present) any time after mid-February and at the time the prairie grass seed begins to germinate. This practice may need to be repeated every 2 years but this depends on the weed seedbank. Such a practice has the potential to lead to a permanent temperate grass pasture.

Grazing fairly lax from October onwards at 20-day to 22-day intervals should allow adequate seed-set to re-establish seedlings the following autumn.

Livestock disorders of particular note Awns may penetrate skin of sheep; possible wool contaminant.
Additional tips Can be established with conventional cultivation or direct drilling.

Acknowledgment

Advice on livestock health was provided by Dr Chris Bourke, Principal Research Scientist, NSW Agriculture, Orange. His contribution is gratefully acknowledged.