Login | Create Account (DAF staff only)

Is land condition a useful indicator of soil organic carbon stock in Australia?

Bray, S. G. and Allen, D. E. and Harms, B. P. and Reid, D. J. and Fraser, G. W. and Dalal, R. C. and Walsh, D. and Phelps, D. G. and Gunther, R. (2016) Is land condition a useful indicator of soil organic carbon stock in Australia? The Rangeland Journal . ISSN 1036-9872

Full text not currently attached. Access may be available via the Publisher's website or OpenAccess link.

Article Link(s): http://dx.doi.org/10.1071/RJ15097

Abstract

The grazing lands of northern Australia contain a substantial soil organic carbon (SOC) stock due to the large land area. Manipulating SOC stocks through grazing management has been presented as an option to offset national greenhouse gas emissions from agriculture and other industries. However, research into the response of SOC stocks to a range of management activities has variously shown positive, negative or negligible change. This uncertainty in predicting change in SOC stocks represents high project risk for government and industry in relation to SOC sequestration programs. In this paper, we seek to address the uncertainty in SOC stock prediction by assessing relationships between SOC stocks and grazing land condition indicators. We reviewed the literature to identify land condition indicators for analysis and tested relationships between identified land condition indicators and SOC stock using data from a paired-site sampling experiment (10 sites). We subsequently collated SOC stock datasets at two scales (quadrat and paddock) from across northern Australia (329 sites) to compare with the findings of the paired-site sampling experiment with the aim of identifying the land condition indicators that had the strongest relationship with SOC stock. The land condition indicators most closely correlated with SOC stocks across datasets and analysis scales were tree basal area, tree canopy cover, ground cover, pasture biomass and the density of perennial grass tussocks. In combination with soil type, these indicators accounted for up to 42% of the variation in the residuals after climate effects were removed. However, we found that responses often interacted with soil type, adding complexity and increasing the uncertainty associated with predicting SOC stock change at any particular location. We recommend that caution be exercised when considering SOC offset projects in northern Australian grazing lands due to the risk of incorrectly predicting changes in SOC stocks with change in land condition indicators and management activities for a particular paddock or property. Despite the uncertainty for generating SOC sequestration income, undertaking management activities to improve land condition is likely to have desirable complementary benefits such as improving productivity and profitability as well as reducing adverse environmental impact.

Item Type:Article
Business groups:Animal Science
Keywords:carbon sequestration, pasture management, soil organic matter, uncertainty.
Subjects:Agriculture > Agriculture (General) > Soil conservation and protection
Animal culture > Rangelands. Range management. Grazing
Animal culture > Feeds and feeding. Animal nutrition
Deposited On:20 Jun 2016 05:26
Last Modified:20 Jun 2016 05:28

Repository Staff Only: item control page