Potential of current perennial plant-based farming systems to deliver salinity management outcomes and improve prospects for native biodiversity: a review

Abstract

Existing perennial plant-based farming systems are examined within 4 climatic zones in southern Australia (western winter rainfall, south-eastern low to medium rainfall, south-eastern high rainfall and northern summer rainfall) to assess their potential to improve the management of dryland salinity. If profit is to be the primary driver of adoption, it appears that the available options (lucerne and other perennial pastures, farm forestry, saltland pastures and forage shrubs) will fall short of existing hydrological targets with the exception of the higher rainfall zones. In the 3 eastern zones, the need to preserve fresh water flows to permanent river systems places limitations on the use of perennial plants, while the higher proportion of regional groundwater flow systems increases response times and heightens the need for regional coordination of effort. In the western zone, the prevalence of local and intermediate ground water flow systems increases effectiveness of individual action. Research into new perennial land use systems has been characterised by an emphasis on water use over profit resulting from poor dialogue between paddock, farm and catchment scales. Exploring the water use implications of land use systems that are potentially viable at farm scale is a more promising approach than focusing on the opportunity cost of catchment scale intervention. Perennial plant-based farming systems present both threats and opportunities to native biodiversity. The major threat is the introduction of new environmental weeds. The opportunities are potential improvements in vegetative cover, food sources and habitat for the native biota, but only where nature conservation goals can influence the structural complexity, composition and location of new land use systems.

Stable carbon isotopes accurately predict diet selection by sheep fed mixtures of C3 annual pastures and saltbush or C4 perennial grasses

“…Perennial shrubs and grasses complement annual grazing systems in mediterreanean-type climates through the provision of a broader seasonal distribution of green feed for livestock (Masters et al, 2006). They may also provide environmental benefits such as maintenance of plant cover to reduce soil erosion and an improvement in the utilisation of rainfall, thus slowing recharge of water tables and dryland salinity (Cocks 2003;Lefroy et al, 2005). Mixed annual/ perennial pastures incorporating subtropical grasses and halophytic shrubs require careful management to optimise the quality and quantities of biomass produced and to maintain the desired botanical composition of the pasture.…”

“…A range of environmental constraints (such as dryland salinity and soil acidity) and economic factors are leading to increased incorporation of perennial plants into farming systems in southern Australia (Cocks 2003;Lefroy et al, 2005). Perennial shrubs and grasses complement annual grazing systems in mediterreanean-type climates through the provision of a broader seasonal distribution of green feed for livestock (Masters et al, 2006).…”

Conservation potential of artificial water bodies for fish communities on a heavily modified agricultural floodplain

“…While broader study results can provide guidance for design of future recycle pits or constructed wetlands to enhance biodiversity values, improvements such as deepening water bodies or planting of riparian zones could also be applied to many on‐farm water bodies. Riparian zones, even artificial, can provide an additional range of benefits such as habitat provision for terrestrial species (Sirami et al ., ), or management of landscape hydrology to avoid secondary salinization (Lefroy et al ., ); a significant sustainability issue for parts of the Burdekin floodplain (Davis et al ., ).…”

On-farm options for managing stream salinity in irrigation areas: an example from the Murray Darling Basin, Australia

“…Catchment scale studies suggest that management of stream salinity requires greater land use ehange than is economically viable (Herron et ai 2003;Tuteja et al 2003). Therefore, rather than focusing on the opportunity cost of catchment scale interventions, exploring interventions that are potentially viable at farm scale could be an appropriate strategy for stream salinity management (Nordblom et al 2004;Lefroy et al 2005). …”