Saltwater couch pastures in the Kimberley

Page last updated: Thursday, 28 June 2018 - 12:07pm

There are many different pasture types in the pastoral rangelands in the Kimberley region of Western Australia. The Department of Primary Industries and Regional Development (DPIRD) provides this pasture information to be used as a reference for assessing pasture condition, and as a guide for pastoral station staff and others interested in the productivity and maintenance of the pastoral rangelands.

Assessments can be used to monitor the success of management and to set goals for improving rangeland condition.

Saltwater couch pastures

These pastures are part of the Sandy soil group pastures, and perennial saltwater couch grass is the identifier grass. Use the interactive key to pasture condition to help identify pasture type.

Pastoral value

Saltwater couch pastures are highly productive pastures that are resilient under grazing when in good and fair condition but should be spelled over the wet season. If possible, cattle should be moved to the less productive Pindan pastures or soft spinifex pastures during this time.

Occurrence

Saltwater couch pastures are tussock grasslands with some halophytic shrubs, dominated by saltwater couch. These pastures occur on broad, flat, saline, coastal plains located above the tidal influence or cut off by coastal dunes. They are found on areas of saline, clay soils on the marine plains from the Broome area south. Small areas also occur on marine plains along the northern coastline.

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Pasture condition

Good: Saltwater couch dominates these pastures in good condition. Other grasses include rice grass and native millet, and some samphire may be present. Some bare ground may be visible, but the sprawling nature of the vegetation in these pastures creates the effect of a carpeted landscape when in good condition.

With increasing salinity, pure saltwater couch pastures grade into salt water couch/samphire pastures. Bare areas will increase along the same salinity gradient so bear this in mind when assessing pasture condition.

Photograph of saltwater couch pasture in good condition
Figure 1 Saltwater couch pasture in good condition in the Kimberley (photograph taken May 2010).  A The saltwater couch plants are dense, matted and vigorous, creating a ‘carpeted’ look and springy feel underfoot; no undesirable species are present.

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Fair: Overuse decreases the proportion of saltwater couch in the pasture, and other species, such as samphire, may initially increase. If grazing pressure remains heavy, the samphire will also decrease as it is trampled and more bare ground will be exposed. In fair condition, the proportion of the intermediate grasses, such as rice grass, will increase along with other intermediate species, such as speedy weed, and undesirable species, such as lippia.

Photograph of saltwater couch pasture in fair condition
Figure 2 Saltwater couch pasture in fair condition in the Kimberley (photograph taken May 2010).  A Saltwater couch plants are present, but lack density and vigour.  B Intermediate species, such as samphire, make up a significant proportion of the pasture; bare ground is visible.

Poor: In poor condition there may be isolated desirable grasses present, but samphire and bare ground make up a large proportion of the surface. Intermediate grasses, such as chloris, sickle lovegrass, rice grass and woollybutt grass, may be present. The bare soil surfaces will be vulnerable to wind erosion late in the dry season under grazing.

Photograph of saltwater couch pasture in poor condition
Figure 3 Saltwater couch pasture in poor condition in the Kimberley (photograph taken May 2010).  A Speedy weed dominates the stand; this annual will die off as the season progresses, leaving large areas of exposed soil late in the dry.  B Quena, an undesirable forb, is present.  C Desirable grasses, such as saltwater couch, are isolated and lack vigour.

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Associated plants

Plants associated with saltwater couch pastures in the Kimberley
Common name
(link to DPIRD species page)

Scientific name

(link to FloraBase)

Life form
Desirable species    

Saltwater couch, marine couch

Sporobolus virginicus

perennial

Buffel grass

Cenchrus ciliaris

perennial

Native millet

Panicum decompositum

perennial

Coastal bluegrass

Bothriochloa ewartiana

perennial

Intermediate species    

Sickle lovegrass

Eragrostis falcata

perennial

River couch

Cynodon dactylon

perennial

Boat panic

Whiteochloa cymbiformis

annual

Speedy weed

Flaveria trinervia

annual

Samphires

Tecticornia spp.

perennial

Frankenias

Frankenia spp.

perennial

Undesirable species    

Lippia

Phyla nodiflora

perennial

Quena

Solanum esuriale

annual

Contact information

Matthew Fletcher
+61 (0)8 9166 4019
Kathryn Ryan
+61 (0)8 9166 4015