© Springer International Publishing AG 2016 521
M. Farooq, K.H.M. Siddique (eds.), Innovations in Dryland Agriculture,
DOI 10.1007/978-3-319-47928-6_19
Salinity in Dryland Agricultural Systems:
Challenges and Opportunities
D.J. McFarlane, R.J. George, E.G. Barrett-Lennard, and M. Gilfedder
1 Introduction
Some soils and landscapes are naturally saline and have excess salts prior to their
development. Such primary salinity has not been considered in this chapter.
Secondary salinity results from changes in the hydrological regime driven by a
combination of hydrological processes that operate across a range of physical scales
and within a range of response time scales (e.g., Peck and Hatton 2003 ).
Secondary, or induced dryland salinity is a world-wide problem in agricultural
systems that have poor internal- (soil profile) and external- (runoff) drainage, which
allows salts to accumulate in the landscape and then be mobilised with changes in
water balance. Salinity occurs in agricultural landscapes primarily for two reasons:
(1) shallow groundwater is present, which leads to salt accumulation at the soil
surface as a consequence of capillarity, and (2) because soils are sodic, which leads
to the accumulation of the small amounts of salt that are always falling in rain
(Rengasamy 2002 ; Barrett-Lennard et al. 2016 ). Secondary water-table induced
salinity can be widespread in arid and semi-arid situations as a consequence of the
leakage of water from irrigation systems, which causes groundwater rise (e.g.,
D.J. McFarlane
The University of Western Australia, Crawley, WA, Australia
e-mail: [email protected]
R.J. George
Department of Agriculture and Food, Bunbury, WA, Australia
E.G. Barrett-Lennard
School of Plant Biology, The University of Western Australia, Crawley, WA, Australia
Department of Agriculture and Food, South Perth, WA, Australia
M. Gilfedder (*)
CSIRO Dutton Park Laboratories, Brisbane, QLD, Australia
e-mail: [email protected]