Increasing soil fertility and altering legume-grass balance as adaptation strategies for sustainable livestock production under climate change

Ghahramani, Afshin and Moore, Andrew d. (2012) Increasing soil fertility and altering legume-grass balance as adaptation strategies for sustainable livestock production under climate change. In: 16th Australian Agronomy Conference: Capturing Opportunities and Overcoming Obstacles in Australian Agronomy (ASA 2012), 14-18 Oct 2012, Armidale, Australia.

Abstract

Climate change is predicted to cause reduction of the annual primary productivity in grasslands across southern Australia. Elevated atmospheric CO2 concentrations are likely to favour legumes over grasses in temperate pastures, but legume residues have weaker structure compared to grass species. As a result, more rapidly degradable ground cover during summer can potentially increase risk of soil erosion. Managing pastures for lower legume content may prevent this issue as an adaptation option but at the cost of reduced
production per animal. We applied the GRAZPLAN modelling tools to simulate potential effects of future projected climates (SRES A2 scenario) on pasture and livestock production of 24 representative livestock farms in southern Australia running five livestock enterprises. We applied historical weather data for 1970 to 1999 (as reference) and projected data from four global circulation models. Pasture and animal production
were simulated for focus years at 2030, 2050 and 2070. At each location, and for each climate, we estimated the sustainable stocking rate with the current pasture composition (legume-grass mixture) and with legumes other than lucerne removed from the pastures. Increased soil fertility was also simulated as an adaptation option. At all examined locations, the legume removal option decreased the profit ($/ha) in comparison with
the no adaptation option. Even applying the legume removal in association with the increased soil fertility could not make significant change from the no-adaptation case. Applying the single adaptation of increased soil fertility could partly recover decline in profitability of the farm systems, however its effectiveness decreased over time.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Speech)
Refereed: Yes
Item Status: Live Archive
Additional Information: Copyright © 2012 Australian Society of Agronomy. Oral presentation - Abstract only published in Conference Proceedings.
Faculty / Department / School: No Faculty
Date Deposited: 30 Nov 2016 23:49
Last Modified: 30 Jun 2017 04:54
Uncontrolled Keywords: climate change adaptation, modelling, agricultural system, pasture, legume removal
Fields of Research : 07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070103 Agricultural Production Systems Simulation
07 Agricultural and Veterinary Sciences > 0701 Agriculture, Land and Farm Management > 070105 Agricultural Systems Analysis and Modelling
URI: http://eprints.usq.edu.au/id/eprint/29991

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