An exploratory analysis of the scope for dispersed small-scale irrigation developments to enhance the productivity of northern beef cattle enterprises

摘要

The major economic use of the northern Australian rangelands is beef cattle grazing. Beef production enterprises are typically large and employ `low-input' herd and pasture management systems, and the longer-term viability and sustainability of many is uncertain. Productivity gains have been stagnant for most of the past decade, and nutritional constraints are a major source of the poor animal production andfinancial returns across the sector. There has been a growing interest in the scope for small-scale, dispersed irrigation developments -mosaic irrigation -to provide an augmented supply of higher-quality forages to certain classes of animals in order to alter their reproduction and/or growth potential and to exploit market opportunities. An ex-ante economic review undertaken by the CSIRO of the prospects for mosaic irrigation employed bioeconomic simulation modelling of case studies of irrigation development scenarios conducted at the individual beef enterprise scale in three contrasting regions of northern Australia -the Burdekin (north Queensland), the Barkly Tableland (Northern Territory) and the Kimberley (northern Western Australia). This paper presents a summary of the methods, results and conclusions of the case study modelling. The results present a mixed picture of the economic potential for the various irrigation development options that were canvassed. The level of animal productivity (e.g. average weight of sale animals) increased for all of the irrigation simulation scenarios, but in most instances the projected economic advantage ranged from negative to only moderately positive across the three regional case studies. Where there was an apparently attractive return on the irrigation investment (e.g. a real internal rate of return of &15%), this primarily occurred under the more buoyant market conditions that have prevailed in recent years. The influence of irrigated forage availability on herd structure through management options such as the early weaning of calves appears to be at least as valuable as changes in liveweight gain for particular classes of animals.