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Plant/Animal Production
Pasture production on the Northern Tablelands
This material addresses aspects of the following syllabus outcome:
A student:
H2.1 describes the inputs, processes and interactions of plant production systems.
Syllabus content areas addressed in this material include:
Students learn about:
- plant production systems
- the constraints imposed by environmental factors, including light, temperature, available moisture, oxygen/carbon dioxide ratios, wind and biotic factors on plant growth, development and production
- the interaction of genotype with environment and the consequent opportunities for plant productivity
Students learn to:
- analyse and interpret agricultural data, for example animal performance measures, climatic information and crop production data.
Source: Board of Studies NSW (1999) Stage 6 Agriculture Syllabus
Grazing systems
In Australia, pastures have been the basis of our sheep and cattle production, providing feed throughout the year. Due to climate and geographical area, livestock production (grazing animals) has been extensive in nature. This is in contrast to many parts of Europe and North America where animals are kept in more intensive conditions, particularly during the winter months when the weather is cold and harsh. Recently has been an increase in the numbers of cattle kept in feedlots but Australia still remains predominantly extensive in its sheep and cattle production.
Extensive animal production in Australia means that pasture production is extremely important. Pastures that provide year round feed, recover well from grazing, reduce the risk of soil erosion and are balanced in the species present are vital for successful sheep and cattle production.
This piece of work provides a model that examines the environmental factors that effect the pasture growth on the Northern Tablelands. Skills such as: collecting climatic data from the Bureau of Meteorology web site and then drawing a graph; comparing rainfall and temperature data with estimated growth rates of several pasture species; and drawing some conclusions about the influence of the climate on the pasture growth; are used extensively.
There are three other activities that you may select from once you have completed this one. Each one uses the skills you will have developed by completing this activity and the climatic information and pasture growth data for a particular climatic region:
- Pasture production on the North West slopes
- Pasture production on the Southern Tablelands
- Pasture production on the South West slopes.
Factors affecting pasture growth and production
Pasture growth is determined by the same factors that determine any plant growth. These include: climate; soil type; topography; and pest and disease susceptability. These factors determine the particular species that can be grown in the particular environment. This is known as the interaction with genotype and environment.
Northern Tablelands
- Choose a site and gather the climatic data for a region.
Glen Innes is located on the Northern Tablelands and Climatic data is available for Glen Innes (Ag Research Station) on the Bureau of Meteorology (Climate Averages)
web site.
This site provides detailed long term mean values of weather data. The only details you need to use are:- mean daily maximum temperature
- mean daily minimum temperature
- mean rainfall
This data can be summarised in a table as shown below:
Month Mean daily max. temperature
(°C)Mean daily min. temperature
(°C)Mean rainfall (mm) January 25.0 13.5 108.0 February 24.4 13.4 92.4 March 22.8 11.5 69.5 April 19.8 8.0 40.9 May 16.2 5.1 50.4 June 12.9 1.7 54.3 July 12.2 0.6 57.6 August 13.7 1.2 49.0 September 16.4 4.0 55.0 October 19.6 7.1 77.0 November 22.0 9.7 85.2 December 24.4 12.1 108.9
- Draw a graph presenting the climatic average data.
Graphs are an excellent way of presenting climatic data as they often present the data in a more meaningful way than tables.
By convention a graph presenting climatic data should be drawn with the rainfall as a histogram and the temperature (both maximum and minimum) as a line graph. This data can be put on the same graph with each y axis (left and right) having different units and labelled according to whether it is the axis for temperature or rainfall.
- Draw a graph of estimated growth rate of pastures on the Northern Tablelands.
Estimated growth rate of pasture types (kgDM/ha/day)
J F M A M J J A S O N D fescue/white and sub clover 58 57 50 28 15 10 10 11 25 44 58 60 phalaris/white and sub clover 28 30 37 34 15 10 10 11 25 43 57 55 red grass dominant pasture 33 32 28 8 2 2 2 2 10 35 39 37 microlaena/white and sub clover 40 36 30 17 10 4 4 5 22 40 47 49 oats 0 0 15 28 20 20 20 22 44 58 56 0
The following graph has been drawn to show the growth rates of a variety of pasture species in the Northern Tablelands using raw data of dry matter gain per day (kg/ha/day).
- Compare the graph presenting the climatic average data
with the graph showing the estimated growth rate of pastures on
the Northern Tablelands. In other words, draw some conclusions
about the influence of climate on the growth rate of pastures of
the Northern Tablelands.
The Northern Tablelands experiences cold winters - this is apparent by the low mean minimum temperatures. This results in depressed pasture growth during the winter, as shown by the trough from May through to August in the graph showing growth rate of pastures.
The Northern Tablelands experiences mild summers with most of the rain falling during the summer months. This favours the growth of the pastures in particular, fescue, white clover and subterranean clover, as seen by the rise in the growth curves from August on into summer. All pasture species continue to grow well into summer with the exception of oats which set seed and die off from October into November. Oats is an annual pasture species which does not appear on the growth curve until February after it has been resown.
It is clear that the cold temperatures of the Northern Tablelands winters affect the rate of pasture growth, therefore limiting the feed available for livestock during this time.
Now that you have worked through this model, complete a similar activity yourself for one of the following climatic regions:
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