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Inter-annual variability in pasture herbage accumulation in temperate dairy regions: causes, consequences, and management tools


Chapman, DF and Rawnsley, RP and Cullen, BR and Clark, DA, Inter-annual variability in pasture herbage accumulation in temperate dairy regions: causes, consequences, and management tools, Proceedings of the 22nd International Grasslands Congress: Revitalising Grasslands to Sustain our Communities, 15-19 September 2013, Sydney, Australia, pp. 798-805. ISBN 978-1-74256-543-9 (2013) [Refereed Conference Paper]

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Copyright 2013 The 22nd International Grassland Congress

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Inter-annual variation in pasture herbage accumulation rate (HAR) is common in temperate dairy regions, posing challenges for farmers in the management of dairy cow feeding and of pasture state. This paper reviews the biophysical factors that cause inter-annual variation, considers some of its consequences for the efficient harvest of pasture, and discusses the basis for decision rules and support tools that are available to assist New Zealand and Australian farmers to help manage the consequences of an imbalance between feed supply and demand. These tools are well-grounded in scientific research and farmer experience, but are not widely used in the Australasian dairy industries. Some of the reasons for this are discussed. Inter-annual variability in HAR cannot be removed, even with inputs such as irrigation, but reliable forecasts of pasture HAR for a month or more could greatly improve the effectiveness of operational and tactical decision-making. Various approaches to pasture forecasting, based on pasture growth simulation models, are presented and discussed. Some of these appear to have reasonable predictive ability. However, considerably more development work is needed to: (1) prove their effectiveness; and (2) build the systems required to capture real-time, on farm data for critical systems variables such as pasture herbage mass and soil water content to combine with daily weather data. This technology presents an opportunity for farmers to gain greater control over variability in pasture-based dairy systems and improve the efficiency of resource use for profit and environmental outcomes.

Item Details

Item Type:Refereed Conference Paper
Keywords:climate variability, decision rules, forecasting
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Crop and pasture production
Research Field:Agronomy
Objective Division:Animal Production and Animal Primary Products
Objective Group:Pasture, browse and fodder crops
Objective Field:Non-cereal crops (non-cereal crops for hay/silage/green feed)
UTAS Author:Rawnsley, RP (Dr Richard Rawnsley)
ID Code:86688
Year Published:2013
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2013-10-11
Last Modified:2014-08-14
Downloads:8 View Download Statistics

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