Can Nassella neesiana, Chilean needle grass, be incorporated into a grazing management system in Australia?
M.R. GardenerA,C, B.M. SindelB, R.D.B. WhalleyA and J.M. EarlA
A Botany, School of Environmental Sciences and Natural Resources Management, University of New England, Armidale, NSW 2351, Australia.
B Agronomy and Soil Science, School of Rural Science and Agriculture, University of New England, Armidale, NSW 2351, Australia.
C Tropical Savannas CRC, Charles Darwin University, NT 0909, Australia.
In Australia, Nassella neesiana (Chilean needle grass) is considered a weed of pastures, whereas, in its native Argentina, it is a desirable component of pastures. This study made a preliminary assessment of its value as a pasture and discusses the potential for its abundance to be controlled by grazing management.
As a measure of pasture productivity, regrowth herbage mass was compared between N. neesiana and Festuca arundinacea. F. arundinacea was more productive in all but one sampling period in October/November 1995. The cumulative regrowth herbage mass of N. neesiana over a 50 week period was 24.3% lower than that of F. arundinacea (0.1986 compared with 0.2623 g cm-2 basal area year-1). The crude protein of N. neesiana green leaf samples ranged from 12.7 to 16.6% while digestible dry matter ranged from 58 to 66%, again somewhat lower than comparable values for F. arundinacea. Nevertheless, these figures, combined with the fact that N. neesiana had a high basal cover (20%), resulted in the production of a large amount of reasonable quality feed. On a whole paddock basis average regrowth production of N. neesiana was calculated to be 2296 kg ha-1 year-1. It is suggested that a cell grazing approach with high stock densities for one to three days followed by rest periods of 40 to 90 days, depending on seasonal conditions and anticipated seasonal growth rates, could result in a reduction in abundance of N. neesiana and an increase in abundance of more valuable competing perennial grasses.
Key words: weed, Festuca arundinacea, crude protein, digestible dry matter, grazing management.
Plant Protection Quarterly (2005) 20 (1) 36-40.