CSIRO PUBLISHING
www.publish.csiro.au/journals/ajar
Australian Journal of Agricultural Research, 2003, 54, 663–675
Drainage and change in soil water storage below the root-zone under long fallow and continuous cropping sequences in the Victorian Mallee Mark G. O’ConnellA, Garry J. O’LearyB, and David J. ConnorC A
Corresponding author; Department of Primary Industries, Victorian Institute for Dryland Agriculture, Mallee Research Station, PB 1, Walpeup, Vic. 3507, Australia; present address: Department of Primary Industries, PB 1, Tatura, Vic. 3616, Australia; email: mark.o’
[email protected] B Department of Primary Industries, Victorian Institute for Dryland Agriculture, PB 260, Horsham, Vic. 3401, Australia; present address: CSIRO Land and Water, Mallee Research Station, PB 1, Walpeup, Vic. 3507, Australia. C Joint Centre for Crop Innovation, School of Agriculture and Food Systems, The Institute of Land and Food Resources, The University of Melbourne, Vic. 3010, Australia; present address: Instituto de Agricultura Sostenible (CSIC), Córdoba, Spain.
Abstract. A field study investigated drainage and changes in soil water storage below the root-zone of annual crops on a sandy loam soil in the Victorian Mallee for 8 years. It was designed to compare the effects of the common long (18-month) fallow in a 3-year rotation (fallow–wheat–pea, FWP) with a rotation in which the fallow was replaced with mustard (Brassica juncea), viz. mustard–wheat–pea (MWP). Drainage was measured over 2 periods (1993–98 and 1998–2001) using 9 in situ drainage lysimeters in each rotation. The first period of ~5 years was drier than average (mean annual rainfall 298 cf. 339 mm) and drainage was low and variable. Drainage was greater under the fallow rotation (average 0.24 mm/year) than under the non-fallow rotation (average
