is there an ideal farming system to maximise stored soil water in the eastern australian, vertosol...
DESCRIPTION
A presentation at the WCCA 2011 event in Brisbane.TRANSCRIPT
Is there an ideal farming system to maximise stored soil water in the Eastern Australian, Vertosol dominated, semi arid sub tropics?
Jeremy Whish
CSIRO. Using models to support farmer decision-making
Key Messages
• Complex systems analysis does not need to be done with a single complex model
• Reducing complex systems to simple messages is useful
• A single picture can capture the learning of 1000 simulations
• Risk and Variability should be managed at both the farm and paddock(field) levels
CSIRO. Using models to support farmer decision-making
Background
Brisbane
Sydney
Walgett
CSIRO. Using models to support farmer decision-making
Background
CSIRO. Using models to support farmer decision-making
The Initial Problem
• Could APSIM be used to identify if our current farming system is matched to our environment ?
CSIRO. Using models to support farmer decision-making
single wheat paddock gross margins19
70
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
-200
0
200
400
600
800
1000wheat_sf
CSIRO. Using models to support farmer decision-making
The starting point
• How much rainfall ?
• When does it fall ?
• How much do you need ?
• How variable is it ?
CSIRO. Using models to support farmer decision-making
How much in crop rainfall (winter)
0.0
0.2
0.4
0.6
0.8
1.0
100
200
300
400
Pro
babi
lity
of e
xcee
denc
e (%
)
Total rainfall (mm)
0
100
200
300
400
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Rai
nfal
l (m
m)
ave= 208
0
100
200
300
400
1957
1994
1940
1902
2002
1982
1914
1965
1911
1929
1927
2006
1905
1928
1919
1946
1972
1977
1926
1953
1980
1941
1937
2004
1915
1967
1932
1944
1908
1918
1936
1922
1951
2003
1943
2001
1961
1987
1900
1923
1975
1935
1992
1976
2007
2009
1945
1974
1904
1968
1960
1997
1912
1990
1910
1971
1959
1989
1907
1970
1952
1913
1931
1938
1948
1999
1991
1963
1984
1958
1917
1985
1964
1996
1956
1930
1934
1909
1962
1995
1979
1901
2005
1966
1988
1939
1954
1986
1947
1973
1925
2000
1993
1969
1924
1942
2008
1998
1903
2010
1921
1978
1916
1983
1981
1906
1949
1955
1933
1920
1950
Rai
nfal
l (m
m)
ave= 208
CSIRO. Using models to support farmer decision-making
How much in crop rainfall (summer)
0.0
0.2
0.4
0.6
0.8
1.0
100
200
300
400
500
Pro
babi
lity
of e
xcee
denc
e (%
)
Total rainfall (mm)
0
100
200
300
400
500
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Rai
nfal
l (m
m)
ave= 219
0
100
200
300
400
500
1900
1901
1944
1932
1989
1951
1959
1899
1928
1919
1915
2002
1968
1964
1982
1930
1918
1986
1965
1939
1945
1943
1938
1937
1902
2001
1922
1912
1984
1914
1966
1985
1941
1904
1978
1905
1911
1926
1929
1988
1995
1921
1957
1936
1981
1993
1913
2005
1999
1935
1979
1952
1920
1987
1997
1948
1909
1972
1967
1990
2006
1956
1931
1934
1980
2003
1998
1977
1996
1927
1906
2004
1950
1953
1992
1970
1963
1946
1903
1923
1924
1908
1960
1917
1925
1971
1969
1940
2000
2009
1976
1910
1947
1942
1907
1974
1991
1961
1949
1933
2010
2007
1916
1962
1958
2008
1983
1954
1994
1975
1973
1955
Rai
nfal
l (m
m)
ave= 219
CSIRO. Using models to support farmer decision-making
How much in crop rainfall (winter)
0.0
0.2
0.4
0.6
0.8
1.0
100
200
300
400
Pro
babi
lity
of e
xcee
denc
e (%
)
Total rainfall (mm)
197219771980
197519761974
19711970
1979
1973
1978
0
100
200
300
400
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Rai
nfal
l (m
m)
ave= 208ave= 193
0
100
200
300
400
1957
1994
1940
1902
2002
1982
1914
1965
1911
1929
1927
2006
1905
1928
1919
1946
1972
1977
1926
1953
1980
1941
1937
2004
1915
1967
1932
1944
1908
1918
1936
1922
1951
2003
1943
2001
1961
1987
1900
1923
1975
1935
1992
1976
2007
2009
1945
1974
1904
1968
1960
1997
1912
1990
1910
1971
1959
1989
1907
1970
1952
1913
1931
1938
1948
1999
1991
1963
1984
1958
1917
1985
1964
1996
1956
1930
1934
1909
1962
1995
1979
1901
2005
1966
1988
1939
1954
1986
1947
1973
1925
2000
1993
1969
1924
1942
2008
1998
1903
2010
1921
1978
1916
1983
1981
1906
1949
1955
1933
1920
1950
Rai
nfal
l (m
m)
ave= 208ave= 193
CSIRO. Using models to support farmer decision-making
How much in crop rainfall (summer)
0.0
0.2
0.4
0.6
0.8
1.0
100
200
300
400
500
Pro
babi
lity
of e
xcee
denc
e (%
)
Total rainfall (mm)
1978
1979
1972
19801977
1970
19711976
1974
1975 19730
100
200
300
400
500
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Rai
nfal
l (m
m)
ave= 219
ave= 291
0
100
200
300
400
500
1900
1901
1944
1932
1989
1951
1959
1899
1928
1919
1915
2002
1968
1964
1982
1930
1918
1986
1965
1939
1945
1943
1938
1937
1902
2001
1922
1912
1984
1914
1966
1985
1941
1904
1978
1905
1911
1926
1929
1988
1995
1921
1957
1936
1981
1993
1913
2005
1999
1935
1979
1952
1920
1987
1997
1948
1909
1972
1967
1990
2006
1956
1931
1934
1980
2003
1998
1977
1996
1927
1906
2004
1950
1953
1992
1970
1963
1946
1903
1923
1924
1908
1960
1917
1925
1971
1969
1940
2000
2009
1976
1910
1947
1942
1907
1974
1991
1961
1949
1933
2010
2007
1916
1962
1958
2008
1983
1954
1994
1975
1973
1955
Rai
nfal
l (m
m)
ave= 219
ave= 291
CSIRO. Using models to support farmer decision-making
The value of stored water
!
CSIRO. Using models to support farmer decision-making
Accumulation of water between crops
CSIRO. Using models to support farmer decision-making
Accumulation of water between crops
CSIRO. Using models to support farmer decision-making
Explore how rotations affect risk
CSIRO. Using models to support farmer decision-making
Explore how rotations affect risk
!CSIRO. Using models to support farmer decision-making
In field decisions
CSIRO. Using models to support farmer decision-making
Conclusion
• Was there an ideal crop rotation for the region that maximised yield and minimised risk ?
• yes but flexible management is needed in a variable environment
• Was simulation modelling the right approach ?
• yes but it needs to be combined with simple models.
CSIRO. Using models to support farmer decision-making
Thank you