farming deep in climate change: the west australia experience

Climate change in the Northern Agriculture Region of WA

- threats and opportunities

Tim Wiley,Department of Agriculture and Food Western Australia

Geraldton

Yearly Rainfall Lynton, Northampton shire, WA

0

100

200

300

400

500

600

700

800

1914

1917

1920

1923

1926

1929

1932

1935

1939

1942

1945

1948

1951

1954

1957

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

mm

Plant available rainfallLynton, Northampton shire, WA

0

100

200

300

400

500

600

700

800

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

mm

“High stocking rate grazing systems to reduce erosion”Northern Agri Group with NLP, NACC & DAFWA

• Farmers recorded stock movements 06/07

• DAFWA calculated grazing days for each paddock

• DAFWA measured ground cover in May 2007

Sand storm 9 April 2007

Annual pasture on sand

30 May 2007

Crop stubble at Murray Carson’s

Perennial grass pasture& tagasaste

y = -10.184x + 66.494

R2 = 0.597

y = -6.4896x + 24.265

R2 = 0.3309

y = -24.92x + 48.578

R2 = 0.5653

y = -7.0001x + 79.94

R2 = 0.8724

0

25

50

75

0 2 4 6 8

Dry Sheep Equivalents / Ha

Gro

und

cove

r %

Annuals on gravel

Annuals on sand

Tagasaste

Perennials

Wheat stuble

Sown fodder

Lupin stubble

Linear (Perennials)

Jim Wedge’s ASCAS, October 2008Soil Corer

Bulk Density sampling

Carson May 2008

Bain February 2008

Gillam Q&Q March 2007

‘Whole soil’ Organic C in the top 30 cm of soil - annuals vs. perennialsPaired paddock sampling

Paddocks Pasture OC% Bulk Density C t/ha CO2e t/ha/yr

Nixon Annual 0.41 1.60 19.7  

  Perennial 0.66 1.60 31.5 10.8

Wilson Annual 0.80 1.57 37.7  

  Perennial 0.94 1.57 44.3 6.0

Forsyth Annual 0.32 1.61 15.5  

  Perennial 0.45 1.61 21.6 3.7

Bain Annual 0.59 1.60 28.1  

  Perennial 0.83 1.60 40.0 11.6

Bain Annual 0.63 1.60 30.4  

  Perennial 0.60 1.60 28.7 -1.6

Carson Annual 0.56 1.38 23.2  

  Perennial 0.69 1.37 28.2 3.9

‘Whole soil’ Organic C in the top 30 cm of soil - annuals vs. perennialsTrial site Pasture Organic C % Bulk Density C t/ha CO2e t/ha/yr

Combes A Annual 0.53 1.38 22.0  

  Green panic 0.64 1.38 26.5 6.1

  Rhodes 0.64 1.38 26.6 6.1

  Kikuyu 0.70 1.38 29.0 9.4

  Lotononis 0.82 1.38 33.9 16.0

Combes B Annual 0.47 1.48 20.9  

  Rhodes 0.58 1.47 25.6 6.3

  Lucerne 0.56 1.47 24.7 5.1

Gillam Annual 0.47 1.28 17.9  

  Rhodes 0.48 1.43 20.6 2.7

  Green panic 0.52 1.43 22.3 4.4

  Signal grass 0.52 1.43 22.5 4.5

Metcalfe Annual 0.79 1.47 34.7  

  Rhodes 0.93 1.47 40.8 8.1

  Kikuyu 0.84 1.47 37.0 3.1

  Lucerne 0.96 1.47 42.1 9.9

  Siratro 0.91 1.47 40.1 7.2

  Bambatsi panic 0.91 1.47 40.1 7.2

  Green panic 0.77 1.47 34.0 -1.0

  Couch 0.83 1.47 36.4 2.2

BRS Annual 0.44 1.42 21.0  

  Kikuyu 0.75 1.37 36.2 11.7

  Rhodes 0.59 1.37 28.2 5.6