Library Open Repository

Emergy analysis of three cropping systems in south western Australia

Downloads

Downloads per month over past year

Lefroy, EC and Rydberg, T (2003) Emergy analysis of three cropping systems in south western Australia. Ecological Modelling, 161 (3). pp. 195-211. ISSN 0304-3800

[img]
Preview
PDF
Emergy_evaluation_of_three.pdf | Download (596kB)
Available under University of Tasmania Standard License.

Abstract

Wind erosion and rising water tables are serious threats to the ecological sustainability of annual plant-based farming systems on deep, infertile sandplain soils in southwestern Australia. In this study, an annual cropping system was compared with two novel perennial plant-based systems designed to address these threats in terms of their use of renewable indigenous resource, their use of non-renewable indigenous resources, their purchased inputs of energy and materials, and profitability. The farming systems were an annual lupin/wheat (Lupinus angustifolius L./Triticum aestivum L.) crop rotation, a plantation of the fodder tree tagasaste (Chamaecytisus proliferus L.) and an alley cropping system in which the lupin/wheat rotation was grown between spaced rows of tagasaste trees. Flows of energy and materials between the environment and the economy were identified for each farming system and the natural and human activity involved in generating inputs as goods or services then valued in terms of the equivalent amount of solar energy required for their production using the emergy method of Odum [Ecological and General Systems: An Introduction to Systems Ecology. University Press of Colorado, revised edition of Systems Ecology, 1983, Wiley, New York, 644 pp.; Environmental Accounting: Emergy and Environmental Decision Making. Wiley, New York, 370 pp.]. The results showed that the two largest energy flows in the conventional lupin/wheat cropping system were wind erosion and purchased inputs of phosphate. The renewable component of production was 15% of total flows in the lupin/wheat system, 30% in the alley cropping system and 53% in the tagasaste plantation. The annual net income from the plantation system was nearly four times higher, and from alley cropping 45% higher, than from the lupin/wheat rotation. This analysis suggested that once the two agroforestry systems were fully established, the tagasaste plantation was the most efficient at transforming natural resources into goods and services and the most profitable, while the lupin/wheat system was the least energy efficient and the least profitable.

Item Type: Article
Keywords: Energy analysis; Emergy; Wind erosion; Water use; Tagasaste; Chamaecytisus proliferus; Southwestern Australia
Journal or Publication Title: Ecological Modelling
Page Range: pp. 195-211
ISSN: 0304-3800
Identification Number - DOI: 10.1016/S0304-3800(02)00341-1
Additional Information: The definitive version is available at http://www.sciencedirect.com
Date Deposited: 29 May 2008 00:00
Last Modified: 18 Nov 2014 03:40
URI: http://eprints.utas.edu.au/id/eprint/6336
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page