Cattle production
Part 1: Growing food for cattle
Introduction ............................................................................... 2
Photosynthesis .......................................................................... 3
The rate of photosynthesis ...............................................................4
Questions .........................................................................................7
Respiration ................................................................................ 9
What is respiration?..........................................................................9
Photosynthesis and respiration ......................................................10
Net assimilation rate.......................................................................11
Experimental design................................................................ 13
Experimental design factors ...........................................................13
Analysis and evaluation of experiments.........................................18
Designing and conducting an experiment ......................................20
Pastures .................................................................................. 30
Introduced pasture .........................................................................30
Native pasture ................................................................................31
Pasture management .....................................................................32
Summary................................................................................. 33
Additional resources................................................................ 34
Suggested answers................................................................. 38
Exercises – Part 1 ................................................................... 46
Part 1: Growing food for cattle
1
Introduction
Introduction
A cattle production system requires cattle food as an input. The amount
of food and its quality will influence how well the cattle will survive and
produce. In the majority of Australian cattle production systems the
plants and animals interact in a grazing system, each one affecting the
other.
This part will begin by examining how a plant utilises solar energy to
produce sugars via the process of photosynthesis. The process of
respiration and the resulting net assimilation rate will also be
investigated. These processes can be manipulated by management
practices to maximise agricultural production.
The principles of experimental design are studied and used to design an
experiment on planting density in grazing oats. This experiment will
take you seven weeks to complete. The use of native and introduced
pastures in grazing systems is then investigated.
This part contributes towards an understanding of Outcome H2.1 from
the Agriculture Stage 6 HSC Course. The syllabus can be found on the
Board of Studies, NSW website at http://www.boardofstudies.nsw.edu.au
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Cattle production
Photosynthesis
Photosynthesis
Access an interactive version of Photosynthesis and Respiration using this
link. Resume with this material on page 14: Experimental design.
Plants obtain energy to grow and develop from the sun. This occurs through
a process called photosynthesis.
photo = light
synthesis = manufacture
The products of photosynthesis provide the basis for plant growth by
providing the chemical building blocks. These building blocks, with
other nutrients absorbed by the roots, allow plants to make all the
compounds needed for their growth and development. Plants then
provide food for humans and other animals either directly or indirectly.
The overall chemical equation for photosynthesis can be summarised as
follows:
sunlight
6CO2 +
carbon
+
dioxide
6H 2 O
water
chlorophyll
sunlight
chlorophyll
C 6 H 12 O 6 + 6O2
simple
sugars
+ oxygen
Photosynthesis is actually a series of reactions in which chlorophyll traps
light energy to split water molecules into hydrogen and oxygen. The
oxygen is released from the plant. Energy rich compounds formed
during the splitting of the water molecules are used to combine the
hydrogen with carbon dioxide to form simple sugars that are the final
products of photosynthesis.
Part 1: Growing food for cattle
3
You should revise Part 1 from Down to earth in your preliminary course
notes on the various parts of plants and their morphology to help you to
understand this work.
Cell organelles called chloroplasts are made up of layers composed of
proteins, lipids (fats) and a green pigment called chlorophyll.
Chlorophyll absorbs the light energy that drives the light reactions of
plants, so photosynthesis can occur wherever plants are green – mainly in
the leaf, but also in the stems and shoots.
Water reaches sites of photosynthesis via the xylem after entering the
plant from the soil through the roots. Carbon dioxide, the other raw
material for photosynthesis, enters the leaf tissue through the stomata
from the atmosphere. Oxygen, released from the cells during
photosynthesis, escapes through the stomata.
Photosynthesis produces simple sugars such as glucose. Glucose is
converted into starch for temporary storage in the leaf. Because starch is
insoluble and too large to be moved to other parts of the plant it is broken
down to sucrose before it is moved. The movement of sugars around the
plant is called translocation.
Figure 1.1: Translocation in plants.
The rate of photosynthesis
The rate of photosynthesis in a plant is affected by environmental factors
such as light, availability of water, temperature, carbon dioxide
concentration, availability of mineral nutrients and by the genetic potential
of the plant. These factors can also be termed constraints or limiting
factors. Any of these factors can limit the rate of photosynthesis.
If the rate of photosynthesis is increased, what will happen to the rate of
growth and development?
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Cattle production
_________________________________________________________
Check your answer.
Light
The diagram below shows that as the intensity of light increases the rate
of photosynthesis increases, until a point is reached where there is no
further increase. From then on the rate remains constant, regardless of
increasing light intensity.
rate of photosynthesis
Tropical plant species
Temperate plant species
shade
light intensity
Figure 1.2: Light intensity and photosynthesis.
Different plants have different light requirements, and their maximum
rates of photosynthesis occur at different light intensities. Ferns tend to
grow best when they are in shady situations because they are suited to
lower light intensities, while some other plants will do well only in full
sunlight. In some horticultural industries, shadecloth and other materials
can be used to create the light intensities preferred by the plants being
grown.
Water
Water is one of the important inputs of photosynthesis, so a shortage of
water will result in a decreased photosynthetic rate. Complete lack of
water will result in the death of the plant. Irrigation is a common
practice in farming to supplement natural rainfall. This ensures that lack
of water will not limit photosynthesis and plant production.
Part 1: Growing food for cattle
5
Temperature
The effect of temperature on the rate of photosynthesis is shown below.
Photosynthesis reaches a maximum then quickly declines at higher
temperatures in temperate species such as wheat and soybean. Tropical
species tend to reach their maximum at higher temperatures.
relative photosynthesis
tropical
species
temperate
species
temp
Figure 1.3: Temperature and photosynthesis.
Carbon dioxide
rate of photosynthesis
As the concentration of carbon dioxide in the air surrounding a plant
increases, the rate of photosynthesis also increases, as shown in the graph
below.
CO2 conc
Figure 1.4: Carbon dioxide and photosynthesis.
The normal concentration of carbon dioxide in the air is 0.03%. Carbon
dioxide concentrations above this increase the rate of photosynthesis. In
some glasshouses, carbon dioxide can be added to the air to achieve
greater growth rates.
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Cattle production
Mineral nutrients
Phosphorus is involved in the capture and transfer of energy in the
photosynthetic process, and magnesium is an important part of the
chlorophyll molecule that initially traps the light energy. Deficiency of
these mineral nutrients will therefore result in decreased photosynthesis
and growth. Fertilisers are commonly used to ensure that lack of mineral
nutrients will not limit growth and therefore plant production.
Genetic potential
Species vary in their ability to carry out photosynthesis. Each species is
best adapted to the environment where they developed. Wheat is suited
to temperate climatic conditions; sugar cane is suited to the warmer
tropics.
Differences in photosynthetic capacity also occur between varieties
within a species. For example, certain varieties of soybean show an
increased photosynthetic rate of up to 20% under the same environmental
conditions.
Questions
1
Answer the following true/false statements about photosynthesis. Code
each of the statements T if you think they are TRUE and F if you think
they are FALSE.
a
Sunlight is essential for the photosynthesis reaction.
b
Photosynthesis takes place in all parts of the plant.
c
Sugars and starch are carbohydrates.
d
Water is taken into the plant through the leaves.
e
Carbon dioxide is taken into the plant through the
stomata.
f
As the intensity of light increases the rate of
photosynthesis will continue to increase indefinitely.
g
Tropical plants have a greater potential for maximum
growth than temperate plants.
h
Water availability has no effect on photosynthetic rate.
Part 1: Growing food for cattle
7
2
Rewrite each of the false statements so they are correct.
______________________________________________________
______________________________________________________
______________________________________________________
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3
A farmer growing flowers in glasshouses achieves higher
temperatures inside the glasshouse than outside. This is due to the
solar radiation trapped in the glasshouse during the day. Carbon
dioxide is also added to the air during the day to increase the
photosynthetic rate of the crop.
The farmer is aiming to increase the rate of photosynthesis of the
flower crop and hence increase the yield. To ensure that this occurs,
the farmer needs to reduce the effects of other limiting factors.
Identify two factors that could limit the photosynthetic rate of the
crop and describe how each one would have an effect on the final
growth of the crop. (Assume that temperature and carbon dioxide
levels would not be limiting.)
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
4
In some crops, for example tomatoes, pruning is carried out to
reduce the leaf cover and thus the effect of shading. Explain why a
farmer would want to prune back some of the leaf cover. What
effect would pruning have on a crop where the marketable product is
not the leaves?
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
Check your answers.
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Cattle production
Respiration
Respiration
Now you will find out what happens to the sugars produced by
photosynthesis.
Some of the sugars produced by photosynthesis are used by the plant for
growth and development. This is important in agriculture as it is how the
plant makes the products that we will harvest, then sell for income.
Some of the sugars are used for other processes within the plant. One of
these processes is respiration.
What is respiration?
Respiration is a process that occurs in all living cells. Simple sugars, are
broken down into carbon dioxide, water and energy. The energy is used
by cells to carry out their metabolic processes.
C 6H
12 O 6
simple
sugars
+ 6O 2
+ oxygen
6CO 2 +
6H 2 O +
carbon + water
dioxide
+
energy
energy
At a superficial level respiration appears to be the reverse of
photosynthesis.
There are some important differences between respiration and
photosynthesis.
•
Respiration occurs continuously (24 hours a day). Photosynthesis
occurs only when there is sufficient light.
•
Respiration occurs in all cells, whereas photosynthesis occurs only in
plant cells where there is chlorophyll.
Part 1: Growing food for cattle
9
Photosynthesis and respiration
Code each of the following statements.
Write P if you think the statement refers to photosynthesis and R if you
think the statement refers to respiration.
______
1
Sunlight is essential for this process to occur.
2
This process occurs 24 hours a day.
3
The process that produces a continuous supply of available
energy.
4
Carbon dioxide is needed for this process.
5
This process occurs only in the green parts of plants.
6.
This process occurs in all living cells.
______
______
______
______
______
Check your answers.
Rates of photosynthesis and respiration
Sugars are produced by photosynthesis. These sugars are used in
respiration. For a plant to grow there must be sugars remaining after use
by respiration. That is, the rate of photosynthesis must be greater than
the rate of respiration.
ratio of sugar production (photosynthesis)
or consumption (respiration)
Study the graph below and answer the questions that follow.
photosynthesis
respiration
MT
6
noon
6
MT
time
Figure 1.5: Rate of sugar production and consumption.
1
10
Identify the period of the day when photosynthesis takes place.
Cattle production
_____________________________________________________
2
Identify the period of the day when respiration takes place.
_____________________________________________________
3
Identify the period of the day when the rate of photosynthesis
exceeds the rate of respiration.
_____________________________________________________
4
Explain the implications of this period (when the rate of
photosynthesis exceeds the rate of respiration) for the plant.
_____________________________________________________
_____________________________________________________
_____________________________________________________
Check your answers.
Net assimilation rate
Net assimilation rate (NAR) is a measure of the growth of plants
resulting from the difference between photosynthesis and respiration. It
gives an important indication of the growth of the crop. NAR is an
estimate of the average rate of dry matter gain per unit area of leaf in a
given time.
The interaction between photosynthesis and respiration is a crucial
relationship that determines the rate at which plants grow.
What factors affect NAR?
They include:
•
rate of photosynthesis
•
rate of respiration – respiration rate is influenced by temperature and
the availability of oxygen and sugars within the plant
•
temperature – high temperatures during the day and low
temperatures during the night give a higher NAR because high day
temperatures increase the rate of photosynthesis and low night
temperatures decrease the rate of respiration
•
nutrient availability such as nitrogen, phosphorus, sulfur and
potassium
•
leaf area – in general the greater the leaf area the more production of
food
Part 1: Growing food for cattle
11
•
proportion of non photosynthetic material – the more roots, stems,
flowers and fruits there are in the plant, the more respiration will
take place compared to photosynthesis
•
photoperiod –daylength affects the amount of photosynthesis carried
out by a plant
•
stage of plant development – at different stages the rates of
photosynthesis and respiration will vary
•
canopy structure – the arrangement of the leaves on a plant can
influence the photosynthetic rate especially if there is excessive
shading of the leaves.
Outline three management practices that could be used by a farmer to
maximise the NAR of the plants being grown.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Check your answers.
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Cattle production
Experimental design
Experimental design
Access an interactive version of Experimental design using this link.
Resume with this material on page 21: Designing and conducting an
experiment.
Experiments are carried out to test predictions. The purpose of an
experiment is to provide evidence to support a prediction or hypothesis.
Sometimes poor experimental design can lead to results that are inaccurate
or invalid. Even experiments carried out by professionals can be poorly
designed. The better the design, the more reliable the results will be.
In the preliminary course (Hands on) you examined how to identify and
use treatment and control in an experimental design. Read Part 2 again
to remind yourself of the terms used and what they mean.
In this part you will investigate other important aspects of experimental
design that you will have to consider whenever you encounter
experiments.
Experimental design factors
You should develop your ability to critically analyse the method used in
an experiment. When analysing a design the following aspects need to
be considered:
•
control
•
randomisation
•
replication
•
standardisation
•
data collection.
You should assess whether each of these areas have been well
accommodated in the design or not.
Randomisation
This is where you use a random method of allocating experimental
subjects to a treatment or treatments. A random method could be tossing
a coin, rolling a dice, drawing numbers or tokens out of a hat, use of
Part 1: Growing food for cattle
13
random number tables or electronically generated random numbers.
The method chosen depends on the one most suited to the experiment.
Use of a random method avoids bias in the experiment, which could alter
the results.
Randomisation is important in experiments so that unexpected variations
can be accommodated without changing the outcome.
Figure 1.6: Avoid bias by generating random numbers.
1
A researcher sets up an experiment taking seeds from a bag one at a
time and placing each seed in a pot. They begin with the pots that will
have treatment A and then continue with those for treatment B. The
seeds have settled in the bag and the larger seeds tend to be towards the
bottom of the bag.
a) Outline how the allocation of seed to pots could result in bias in
this experiment.
__________________________________________________
__________________________________________________
b) Outline a random method of allocating seeds to pots that would
avoid bias.
Check that your outline mentions:
•
the random method used, for example, tossing a coin
•
how the random method is used for allocation
•
how the method avoids bias.
__________________________________________________
__________________________________________________
__________________________________________________
__________________________________________________
2
14
The researcher randomly allocates seeds, pots and treatments and
then lines up the treatment A pots on one side of the greenhouse, and
Cattle production
the treatment B pots on the other side. It is known that the watering
system in the greenhouse is uneven, and one treatment will get more
water than the other.
a) Explain why this arrangement of pots could result in a biased
experiment.
_________________________________________________
_________________________________________________
b) Outline a random method of pot arrangement to avoid bias in
the greenhouse.
_________________________________________________
_________________________________________________
_________________________________________________
Check your answers
Replication
Replication is also important in making the result more reliable.
Figure 1.7: Is the difference due to the treatment or the uneven watering?
Review the situation outlined in question 2 on the previous page.
Imagine if the researcher had only one pot of each treatment. The level
of error in the experiment (caused by the faulty watering system) could
not be distinguished from the effect of the treatment itself. This situation
would be likely to result in incorrect experimental conclusions. Having a
number of pots with the same treatment means that slight variations are
averaged out and the results are more accurate.
Part 1: Growing food for cattle
15
How many replicates are needed?
The more replications there are the more reliable the results of the
experiment become. However, every experiment has restricted
resources, for example, land area, labour or money. Good experiments
will include as many replicates as possible given the restrictions. The
more replicates, the more confident you can be of accurate results.
Whenever you are evaluating an experimental design you should
consider whether there are sufficient replicates. If there are few
replicates and the treatment results are not very different, then the
experiment may show an inaccurate result. The researcher should be
cautious in making recommendations. Animal experiments, especially
those dealing with larger animals are likely to have fewer replicates than
plant experiments.
Standardisation
An experiment will have a variable that is being tested. If all conditions
except the variable are the same then any difference in the results must
be due to the variable.
When evaluating an experimental design consider how well particular
aspects of the experiment have been standardised. You should mention
aspects that are kept the same as well as those that might be different.
List aspects that could be standardised in an experiment involving a field
crop.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Check your answer.
The more standard the conditions the more reliable the results of the
experiment.
Data collection
All experiments need to have a way of evaluating the effect of the
variable. This must be in the form of a measurement. In agricultural
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Cattle production
experiments it is common to compare the amount of the agriculturally
important product. For example an experiment using cabbages would
compare the weight of the cabbage heads for each of the treatments to
decide which was the better treatment.
Figure 1.8: The cabbage head is the agriculturally important part of the crop
Complete the following table to show what part of the plant or animal you
could measure and the units you could use.
Plant or Animal
Part measured
Units
cabbages
cabbage head
kilograms/ ha
layer chickens
wheat
beef cattle
Check your answer.
Decisions about measurement
The method of making measurements should be decided before the
experiment begins.
If an experimenter needs to measure the leafy parts of a plant, then
measuring the length and number of leaves will give you limited
information about the quantity of leaf. A better indicator is to weigh the
leaf parts. However, this will destroy the plant so it may be unsuited to
ongoing experiments.
A problem with weighing is that a large proportion of a leaf will
generally consist of water. The amount of water will vary according to
the environmental conditions at the time it was cut, so for better accuracy
Part 1: Growing food for cattle
17
the leaf is usually dried in an oven so that the dry matter weight can be
established. This measurement is also useful when comparing nutritional
values of different animal feeds.
Analysis and evaluation of experiments
Analyse is one of the key words used in the Board of Studies syllabuses
and examinations. It has a particular meaning when used in HSC exam
questions.
Analyse – identify components and BOS NSW 1999 The New Higher
School Certificate Assessment
the relationship between them;
support Document
draw out and relate implications
To analyse an experimental design you need to:
•
identify the design aspects
–
control
–
randomisation
–
replication
–
standardisation
–
data collection
•
provide details of how well each design aspect is addressed
•
outline the implications of the good and bad points of the design.
•
indicate how the design could be improved.
Now you will analyse the design of the wheat variety experiment that
follows.
Wheat variety experiment
Two adjoining fields of the same size are selected for a trial. These
fields have similar cropping histories. Nutrient and pH tests show similar
results for each. Soil texture and structure are the same.
The fields are cultivated at the same time, with the same machinery. A
combine seeder is used to plant wheat seed and add superphosphate
fertiliser at the same rate for each field. One field is planted with the
previously used Cunningham variety and the other field with the new
Sunco variety.
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Cattle production
Figure 1.9: Wheat crop.
When spraying for the weed ryegrass is required, the same herbicide is
applied with a boomspray to both fields at the same application rate.
When the grain has ripened the fields are harvested separately, and the
resulting grain from each field is weighed.
Analyse the experimental design.
_________________________________________________________
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_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Part 1: Growing food for cattle
19
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Check your answer.
Designing and conducting an experiment
You will be using all the aspects of experimental design you have learnt
to design and conduct an experiment on the effect of planting density on
grazing oats.
Oats are a very flexible crop that can be used for grain, hay and forage
(green feed). They are widely used in the southern states of Australia for
winter forage production as they have higher daily winter growth rates
than other cereals and most pastures.
Aim
The aim of the experiment will be to determine the optimum planting
density for maximum dry matter production of grazing oats.
Planting density
When an oat plant first emerges it has a single leaf. It will grow more leaves
until there are about four. At this stage the plant develops tillers. A tiller
will grow from the plant stem near ground level; it looks a bit like another
plant growing very close. The more space that the plant has around it, the
more tillers it is likely to develop. A crowded plant might not develop tillers
at all, and instead, grow taller to better compete for sunlight.
Look at the following diagram showing the growth stages of cereal crops.
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Cattle production
Figure 1.10: Growth stages of cereal crops (Adapted from NSW Agriculture
Winter Crop Variety Sowing Guide 2002).
Usually about 6–8 weeks after emergence grazing oats have livestock put
onto them for their first grazing. When the plants have been eaten down
to about 10 cm above soil level, the livestock are removed and the plants
are allowed to recover. Depending on the growing conditions, the farmer
might get two or three grazing periods from the oats. After grazing, dual
purpose varieties are locked away from livestock and grain is allowed to
develop for harvest. If plants are very crowded they will not have
enough resources available to produce well developed reproductive parts.
yield reproductive)
The following graph illustrates how reproductive yield changes as plant
density increases for a given area. Notice that as the density increases, so
does yield until the plants become too crowded and yield starts to
decline.
density
Figure 1.11: Reproductive yield and density (Based on Lovett et al, 1988, p 47)
Part 1: Growing food for cattle
21
In this experiment we are interested in maximising the amount of dry
matter produced for the first grazing in a given area. Smaller numbers of
plants do not necessarily mean less production because more tillers will
be produced, but at a very low density the tillers will not fill the space,
and production for the area will decrease. At increasing densities
production should remain high, although the size of individual plants will
decrease.
yield (vegetative)
Sketch in the space below the shape of the vegetative production curve you
would expect as density is increased.
density
Figure 1.12: Vegetative yield and density.
Check your answer.
Experimental design
In this experiment you will plant oat seeds at different densities in a
series of large pots, and grow them for seven weeks. Then you will
harvest the oat leaves and stems by cutting them 10 cm above soil level.
The leaves and stems from each pot will be placed in a numbered paper
bag, dried, then weighed to obtain a measurement of the dry matter
produced by each pot.
Before you begin you will need to develop your experimental design.
1
Identify the variable that you will be testing in this experiment.
_____________________________________________________
2
Explain how the design aspect of a control is included in this
experiment.
______________________________________________________
______________________________________________________
______________________________________________________
3
22
Explain how randomisation can be used in the experiment to avoid
bias.
Cattle production
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
Consider the reasonable limits of the resources you have available for the
experiment. In this sort of experiment you will need more than two
treatment levels so you can better find the optimum planting density.
Each treatment will need to be replicated a number of times. Due to
resource limits there will need to be a compromise between pinpointing
the best planting density and the accuracy of the result.
4
Identify what you would consider to be a reasonable number of
treatment levels and replicates for this experiment.
_____________________________________________________
_____________________________________________________
Check your answers.
Now you will need to decide the density of seeds in each treatment. It is
recommended that the lowest density should be a single plant in a pot
(the spacing is then the distance to the next pot).
Normal spacing of oats in the field varies with the conditions, but
generally it is approximately 10–20 cm between each plant. If you are
considering four treatment levels you could have one that is very close,
perhaps 2 or 3 cm spacing, and then the other two treatments at
intermediate levels to give a range of spacings.
Part 1: Growing food for cattle
23
Resources
You will need to assemble the following resources for the experiment.
Immediately:
In seven weeks time:
•
a number of large pots
•
shears or scissors
•
potting mix sufficient to fill the
pots
•
ruler
•
paper bags
•
fertiliser and standard scoop or
scales to ensure the same
amount is added to each pot
•
marking pen to label bags
•
microwave oven
plant labels and waterproof
marker pen
•
microwave safe cup
•
water
•
oat seed
•
•
ruler
scale (as accurate as
possible)
•
measuring jug
•
paper and pen for recording
•
water.
•
clock for timing.
•
Planting
In order to standardise the experiment it is important that everything,
apart from the planting density, is kept as similar as possible.
1
Fill each pot with potting mix to 2–3 cm from the top of the pot.
Take care when handling potting mix as some microorganisms that thrive in
the nutrient rich potting mix can make you ill if you inhale or accidentally
eat them. Read the label on the potting mix bag and follow the safety
instructions. Wash your hands properly after handling the potting mix.
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Cattle production
2
Fertiliser should be added in measured quantities to each pot.
Farmers generally provide phosphorus and nitrogen fertilisers when
growing grazing oats. If you have access to fertilisers such as
superphosphate and Nitram® these can be used, otherwise check the
label of the fertiliser you have available and ensure it contains these
elements. Incorporate the fertiliser evenly within the top 10 cm of
the pot so all the plants will have the same access.
3
Label the pots with numbers. Use a random method to allocate them
to each treatment. Add the treatment to the label so you know which
pot belongs to which density level.
4
Plant seed in each pot in the numerical order of the pots. Seed
should be planted at a depth of about 2.5 cm. Extra seeds can be
planted in each pot in case some do not sprout. Excess plants should
be thinned as soon as they emerge. Use a ruler to position the seeds
at the correct density for each treatment.
5
Try to find a position for the pots that does not have varying
environmental conditions, for example, partial shade. If you group
the pots closely, rather than have them spread out in a long line, the
environmental conditions are likely to be more similar. Situate each
pot in your space using a random method. Do not group the same
treatment together.
Figure 1.13: Partial shade in the experiment area could alter the results.
Part 1: Growing food for cattle
25
6
Measure the same amount of water and apply slowly to each pot.
Water the pots well to start germination. Check the pots regularly to
see if they are drying out and give all the pots a measured amount of
water.
Harvest
After about seven weeks the oats should be at the growth stage where
they are ready for grazing. You will simulate this by using scissors or
shears to cut the oats. Cut the oats one pot at a time.
26
1
Cut the oats 10 cm above the soil surface. Use a ruler to check the
height.
2
Cut the oats into pieces of approximately 1 cm length.
3
Identify the treatment by writing it on a paper bag. Collect all the
cut material and place it into the bag.
4
Use the following procedure if you have a microwave oven:
•
put the paper bag with the cut oats and a microwave safe cup 3/4
full of water into the microwave oven
•
microwave on high for 4 minutes
•
let the bag stand for 4 minutes
•
weigh the bag and record the weight
•
refill the cup so it remains 3/4 full and microwave the cup and
bag for 1 minute
•
let the bag stand for 1 minute and then weigh
•
record the weight
•
continue to microwave for 1 minute and then let stand for 1
minute until the weight does not change
•
subtract the weight of the paper bag to find the weight of dry
matter produced for that pot. Record this weight along with the
identifying information from the bag.
Cattle production
If you do not have a microwave you may have access to a science
laboratory oven at school. If you leave the oats at 105oC for 3 days (over
the weekend would be good) they will reach a point called oven dry, after
which they will no longer be able to lose moisture and you can then
weigh them directly from the oven.
If you have no other option you could use a conventional oven. Place all the
bags onto a tray in an oven set at about 105oC. It may be difficult to set
some domestic ovens at this low temperature, so you will need to supervise
the drying as higher temperatures could present a fire hazard. Dry the
material for as long as you can manage. Due to the shorter drying time the
material will not be truly oven dry, but as long as all the bags are dried for
the same time period, the results should be comparable. Take the bags
directly from the oven and weigh them. Do not forget to subtract the weight
of the bag from your measurement.
Presentation
When you have weighed the oats you will have a series of measurements
called raw data. This raw data needs to be altered to make it more
meaningful. Sometimes the raw data is processed into more meaningful
numbers, for example, by calculating a mean or standard deviation for
each treatment. One way that the data can be presented is in a table. A
table usually groups the data into columns or rows.
Another common method of presentation is as a graph.
A good table or graph will allow the reader to quickly see the trend in the
important data. When you look at tables and graphs try to be critical of
their arrangement and value. Poor presentation of data includes tables
with no sorting and multiple graphs that have no purpose.
Part 1: Growing food for cattle
27
Have a look at the examples of data presentation in the Additional resources
section. Each one presents the same set of data, from a germination
experiment, in a different way. Look for examples that show the data more
clearly. Write down reasons why the presentation of some examples is good
and others are poor.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Check your answers.
In many experiments there is such a lot of raw data collected that the
experimenter may include only processed data, and may put raw data in
an appendix or not in the report at all.
You will need to present your data from the oats experiment.
•
Construct a table that presents the raw data, and a mean and standard
deviation for each treatment.
•
Construct one graph to show as clearly as possible the most
important information.
Interpretation
The next stage is to draw conclusions from your data. A professional
researcher has several options, they could:
•
give their data to a statistician
•
use a statistical program on a computer
•
manipulate the raw data into a complex statistical formula or test that
suits the experimental design
•
examine simple statistical calculations such as mean and standard
deviation.
In the core of the HSC course we will only need to use the simpler option
of comparing means and standard deviations. If you do not know how to
perform these calculations, this is looked at in Part 4 of Grape
production.
28
Cattle production
Be critical of the interpretation of results in experiments that you see.
Sometimes there is such a significant difference between treatments that
the interpretation of the results is easy. More often it is difficult to tell
whether there is a difference between the treatments or not. Sometimes
even professional researchers are so anxious to find a difference between
treatments that they will claim one even though the data does not really
support it.
Is the new treatment better?
The mean is a bit higher,
so I will say it is!
How do I decide?
But the standard
deviation is so big...
Figure 1.14: Decisions.
Write up the first two parts of the Exercise 1.1 report. You will need to
complete and send this report to your teacher after you have finished drying
and weighing the oats.
Post experiment
Do not discard your oat plants immediately after you have completed the
experiment. Continue to care for them. Observe how the plants grow
and recover after your simulated grazing.
Grasses are adapted to resist damage by grazing animals. The growing
points of grasses are close to or slightly under the ground, so that they are
not affected by removal of the upper parts of the plant.
Part 1: Growing food for cattle
29
Pastures
Pastures
The mixture of different plant species in a grazing system is called a pasture.
A pasture is usually a mixture of legumes and grasses, each providing the
animal with different nutrients.
A legume, in association with the correct symbiotic bacteria, is able to fix
nitrogen from the atmosphere and incorporate it into the plant matter.
This is looked at in Part 1 of Grape production. Nitrogen is a major
component of protein, so the high level of nitrogen means that legumes
are an important source of protein for the grazing animal.
Grasses are very high in carbohydrates. Some of the carbohydrate is
starch, but the structural part of grass is mostly cellulose. The cellulose
provides important roughage in the diet of a ruminant animal. Revise
this from Part 3 of Looking at ewe.
Complete the following sentences.
1 Carbohydrates provide animals with __________________
2
Protein is needed by animals for _____________ and
_________________
Check your answers.
Pastures can range from plant communities that consist of native plant
species to pastures consisting of introduced species.
Introduced pasture
The use of European agricultural methods in Australia has meant that in
many areas, particularly the southern temperate regions, the existing
native pasture has been removed and replaced with high producing
species from other countries. This is called pasture improvement. For
best performance these species usually require relatively high levels of
inputs like fertiliser and water (irrigation). These pastures also require a
high level of management to perform well.
30
Cattle production
Species selection is based on the compatability of the species, their
suitability to the local climate and soil, and the yearly feed requirements. It
is usual to select a mixture of grasses and legumes. Legumes build up the
levels of soil nitrogen and grass will use this nitrogen to grow faster. Tall
grasses are not only less digestible for livestock, but will shade legumes,
reducing their growth. Grasses keep out weeds and reduce the risk of bloat
caused by legumes. A good manager will try to maintain a balance of
legume and grass in the pasture. Management techniques that can be used to
manipulate the pasture balance include:
•
timing and intensity of grazing
•
cutting for hay or slashing tall pasture
•
addition of fertiliser
•
control of pests or diseases
•
resowing pasture.
Native pasture
In many parts of Australia there has been little or no pasture improvement.
Large expanses of grazing land in the northern parts of Australia have
climatic and soil conditions that make the land unsuitable for intensive
agricultural production. Cattle are kept here at a very low stocking rate, as
higher rates would result in removal of vegetation and erosion. This type of
agriculture involves very few inputs, and is well suited to the use of native
pasture species.
For many years the management and qualities of native pastures were
generally ignored, but in recent years there has been increased interest in
the use of native pastures, and a number of institutions are currently
undertaking research.
Native species are well adapted to the specific areas where each is found.
This high level of local adaptation means that they will continue to live
(persist) in very adverse conditions, like areas with low rainfall and
extreme heat or fire, and they do not require high input levels.
Unfortunately native pastures are usually less digestible, less palatable
(tasty) and slower growing. Researchers have also had some trouble
collecting, cleaning and sowing native pasture seed.
1
Outline the advantages of native pasture.
_____________________________________________________
_____________________________________________________
_____________________________________________________
Part 1: Growing food for cattle
31
2
Outline the advantages of introduced pasture species
______________________________________________________
______________________________________________________
______________________________________________________
Check your answers.
Despite the difficulties, some native species have been domesticated, and
plant breeders have developed cultivars that are suited to various
conditions. A good example of a domesticated native pasture species is
wallaby grass.
Answer the questions in Exercise 1.2 using the Agfact P2.5.39 Wallaby
grass – a domesticated native grass. This agfact can be purchased from
NSW DPI or downloaded free from their website at
http://www.agric.nsw.gov.au
Pasture management
The usual objective of a pasture manager is to grow pasture that can
sustainably maintain maximum animal production.
Sustainability, as you will remember, is the development of a balance
between profit, and the maintenance of a healthy environment that will
continue to produce in future generations.
Use information about pastures in this part, and from Part 2 of Crop this
to help you answer the following question.
Outline sustainable management practices that can be used in a pasture
production system.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Check your answer.
32
Cattle production
Summary
Summary
•
Photosynthesis is a process that occurs in the green parts of plants.
•
The chemical equation for the photosynthesis reaction can be
summarised as:
6CO 2 +
•
6H 2 O
sunlight
chlorophyll
C 6H
12 O 6
+
6O 2
Factors that affect the rate of photosynthesis include:
–
temperature
–
light
–
availability of water
–
carbon dioxide concentration
–
availability of mineral nutrients
–
genetic potential of the plant.
•
Respiration is a process that occurs in all living cells, 24 hours a day.
•
The reaction of respiration can be summarized as:
C 6H
12 O 6
+ 6O2
6CO 2 + 6H 2 O + energy
•
NAR is a measure of plant growth resulting from the difference
between photosynthesis and respiration. For a plant to grow, the rate
of production of material by photosynthesis must exceed the rate at
which this material is used in respiration.
•
Good experimental design incorporates the elements of:
–
control
–
randomisation
–
replication
–
standardisation.
•
Planting density affects production levels in a predictable curve.
•
Pastures are usually a mixture of grasses and legumes.
•
Improved pastures are high producing, digestible and palatable, but
have high levels of management and inputs.
•
Native pastures are locally adapted and persistent, with low input
levels.
Part 1: Growing food for cattle
33
Additional resources
Additional resources
Results of seed germination trial
Seeds were placed in nine saucers and randomly allocated to three areas with
different temperatures; a bench, a fridge and a warm cupboard. The number
of seeds that germinated in each saucer was counted. The results follow.
Saucer 1
Saucer 2
Saucer 3
Bench
23
17
12
Fridge
5
1
2
15
24
17
Warm cupboard
Total Germinated
116
Example 1
Bench
Fridge
Warm cupboard
23
5
15
17
1
24
12
2
17
Total
52
8
56
Mean
17.3
2.7
18.7
St Dev
5.5
2.1
4.7
Example 2
34
Cattle production
30
Bench
25
Fridge
Warm cupboard
20
15
10
5
0
1
2
3
Saucer Number
Example 3
200
Bench
Fridge
150
Warm cupboard
100
50
0
1
2
3
Saucer Number
Example 4
Part 1: Growing food for cattle
35
25
20
15
10
5
0
Bench
Fridge
Warm cupboard
Temperature
Example 5
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
Bench
Fridge
Warm cupboard
Temperature
Example 6
36
Cattle production
6
5
4
3
2
1
0
Bench
Fridge
Warm cupboard
Temperature
Example 7
Part 1: Growing food for cattle
37
Suggested answers
Suggested answers
The rate of photosynthesis
If the rate of photosynthesis is increased, the rate of growth and
development will also increase.
Questions
1
Statements a, c, e and g are true.
Statements b, d, f and h are false.
2
3
38
b
Photosynthesis takes place in the green parts of plants.
d
Water is taken into the plant through the roots.
f
As the intensity of light increases, the rate of photosynthesis will
only increase while no other factors are limiting.
h
Water availability does have an effect on the photosynthetic
rate.
You should name two of the three factors named below. Then you
should describe how each of your chosen factors will limit the
photosynthetic rate of the crop and finally the growth of the crop.
•
light is essential as the energy to drive the photosynthesis
reaction. If plants have their amount of light decreased then the
energy for driving photosynthesis is decreased and hence the
growth of the plant is decreased.
•
water is an essential reactant in the photosynthesis reaction. If
the amount of water is limited then photosynthesis is limited
and therefore the growth of the plant will be limited.
•
decreased soil fertility, particularly decreased levels of
phosphorus can limit photosynthesis. Phosphorus is essential
for the photosynthesis reaction to proceed. Therefore if
photosynthesis is reduced then plant growth will be reduced.
Cattle production
4
Some farmers producing crops such as tomatoes prune back the leaf
cover to reduce the effects of shading. When the leaves are in shade
they are unable to carry out photosynthesis and hence are not
producing food for the plant. These leaves although they are not
producing food are using up valuable resources of water, nutrients
and the products of photosynthesis but are unable to contribute to the
growth of the plant. Hence they are removed.
Photosynthesis and respiration
1
Sunlight is essential for this process to occur. P
2
This process occurs 24 hours a day. R
3
The process that produces a continuous supply of available
energy. R
4
Carbon dioxide is needed for this process. P
5
This process occurs only in the green parts of plants. P
6
This process occurs in all living cells. R
Rates of photosynthesis and respiration
1
Five am until seven pm
2
Twenty four hours a day.
3
Eight am to four pm.
4
It means that this is the period when there is more food produced
than is broken down to produce energy.
Achieving maximum NAR
Below is a list of some of the management practices that a farmer could
carry out to maximise the NAR of crop plants. You only need to have
outlined three of these.
•
Ensure adequate water for the crop, by irrigating, mulching the soil
surface or increasing the organic matter content of the soil.
•
Ensure adequate soil fertility, particularly of the nutrients nitrogen,
phosphorus, sulphur and potassium, by adding fertilisers, adding
compost and ensuring the correct pH level so that all nutrients are
available.
•
Try to increase the proportion of photosynthetic material on the
plant. This means that rate of photosynthesis can outstrip the rate of
respiration.
Part 1: Growing food for cattle
39
•
For crops grown in glasshouses, artificial lighting can be used to
increase the photoperiod.
•
For crops grown in glasshouses, temperature can be manipulated to
increase the daytime temperature and decrease the night temperature.
•
The crop can be pruned to reduce the amount of shading of leaves so
that all leaves can have the chance to photosynthesise. Otherwise
the shaded leaves will be respiring but not photosynthesising and
hence wasting energy.
Experimental design factors
1
a)
The size of the seed could affect how well the plant grows (this
becomes another variable in the experiment). Treatments A and
B may not have any real difference, but the difference in seed
size could alter the result.
b) There are two ways that you could approach this; you could
randomly allocate the seed to the pots or you could randomly
allocate the pots to treatment. Both would remove bias.
You could number all the pots and put the numbers on pieces of
paper in a bag. Drawing out the pot number indicates that it is
the next to have a seed placed in it. You could fill all the pots
and then toss a coin to decide if each pot is treatment A or B.
2
a)
The amount of water the pots receive may cause one group to
grow better than the other and thus alter the results of the
experiment.
b) The researcher should avoid positioning the pots from a single
treatment as a block because will always be variations in the
environment.
It would be best to try and fit all the pots on one side of the greenhouse.
Even then there could be uneven levels of water (or other environmental
variations), so the researcher should try to randomly allocate the pots to
the area. This could be done by numbering the positions and the pots,
then writing the numbers on paper and putting them in two containers.
Simultaneously drawing a number from each container will randomly
match a position with a pot.
Standardisation
The soil should be as uniform as possible, including texture, structure,
pH, slope, nutrient levels, organic matter levels and depth of topsoil. The
previous cropping history should be the same over the area. Shading and
windbreaks should be avoided as they provide uneven protection across
the site. If irrigation is provided it should be uniform. The same
methods of cultivation, sowing, fertiliser application, pest and disease
control and harvesting should be used.
40
Cattle production
Data collection
Plant or animal
Part measured
Units
cabbages
cabbage head
kilograms/ hectare
layer chickens
eggs
number of
eggs/chicken/year
wheat
grain
tonnes/hectare
beef cattle
weight gain
kilograms/head/year
Wheat variety experiment
The usual variety Cunningham is included in the trial to act as a control
to compare with the new variety, Sunco. If Cunningham was not
included in the trial then the experimenter would not be able to tell if the
new variety was better or not.
The fields are not randomly allocated to the treatments. This means that
the experiment could be biased by slight differences in the conditions in
each field. The implication is that the outcome of the experiment may be
altered and the results unreliable. The experimenter should use a random
method such as a coin toss to decide which field is planted to each
variety.
The experiment has no replication, which means that the results are open
to error. Something unexpected such as insect damage to one field can
easily alter the outcome. Differences or errors in the way the two fields
are managed will not be distinguishable from differences caused by the
treatments. To overcome this the experimenter should divide the
available fields into smaller areas so that there are at least four replicates
of each treatment. These eight smaller plots should then be allocated
randomly to treatments.
The experiment appears to be well standardised; with every aspect kept
as similar as possible, including soil qualities and management
operations. It is important to maintain this high level of standardisation
as it will ensure the validity of the outcome, making the result more
reliable. Without standardisation any differences may be due to factors
other than the treatment.
The experiment has used an appropriate form of data collection, the
weight of the grain indicates how useful each variety will be in a
commercial setting as this is the valuable agricultural product. Weight is
also a practical measurement to collect as after harvesting the grain is
Part 1: Growing food for cattle
41
routinely weighed to determine payment. Collecting data on other
aspects of crop growth such as leaf length would be difficult and would
not provide useful data.
yield (vegetative)
Planting density
density
Based on Lovett et al, 1988, p 47
Experimental Design
1
Planting density.
2
The treatments provide a comparison against each other, so they act
as controls for each other. An absence of oat plants is not a
reasonable option in this experiment.
3
The seeds should be randomly allocated to pots. Pots should be
randomly allocated to positions. This can be done by allocating pots
to treatments, numbering the pots, then drawing numbers from a hat
to decide which pot gets seed next. The numbers in the hat can be
drawn again to decide the positioning of the pots in the available
area.
4
A minimum number of replicates for each treatment is probably four
pots. Four different densities are likely to give an indication of the
optimum level. This would give a total number of pots as 4 x 4 = 16
pots.
If your resources allow you might consider a larger and more accurate
trial.
42
Cattle production
Presentation
Example 1 – table
ƒ
presents all the raw data
ƒ
groups data from the different locations together
ƒ
makes it seem that the saucer number is the variable
ƒ
does not include processing of the data such as mean or standard
deviation
ƒ
includes total germinated, which is not relevant or useful.
Example 2 – table
ƒ
presents all the raw data
ƒ
groups data from the different locations together
ƒ
clearly indicates that the locations are the variable
ƒ
includes mean and standard deviation
Example 3 – graph
ƒ
presents all the raw data
ƒ
makes it seem that the saucer number is the variable
Example 4 – graph
ƒ
presents all the raw data
ƒ
makes it seem that the saucer number is the variable
ƒ
joining the points makes it seem that the data could be continuous
instead of being distinct measurements
ƒ
poor choice of scale means that little difference can be seen between
the results
Example 5 – graph
ƒ
presents all the raw data
ƒ
clearly shows that the location is the variable
ƒ
groups the results from each location together so they can be
compared – can easily see the range of results for each
Part 1: Growing food for cattle
43
Example 6 – graph
ƒ
allows easy comparison of locations
ƒ
does not show all data, so cannot see how variable the results are for
each location
ƒ
the scale emphasizes the difference between the locations by starting
at 2 instead of 0
Example 7 – graph
This type of graph is sometimes included in reports in addition to other
graphs, with the mistaken belief that more is better.
ƒ
alone does not really show anything useful to somebody trying to
understand the data
ƒ
joining the points makes it seem that the data could be continuous
instead of being distinct
Pastures
1
Carbohydrates provide animals with energy.
2
Protein is needed by animals for growth and production.
Native pasture
Native pastures
•
Do not require high levels of inputs like fertiliser and irrigation.
•
Well adapted to the specific areas where found.
•
Persistent in adverse conditions, like low rainfall, extreme heat or
fire.
Introduced Pastures
44
•
High producing and faster growing.
•
More digestible and palatable.
•
Seed easier to collect, clean and sow.
Cattle production
Pasture management
•
Select pasture species that are suited to the local environmental
conditions to reduce the quantity of inputs to the system.
•
Use native pasture species to reduce the use of inputs such as
fertiliser and irrigation.
•
Pasture species can be used that assist in the control of pests or
diseases of other crops. For example, lucerne pasture controls
skeleton weed, a weed pest of wheat.
•
Sowing pest or disease resistant pasture varieties means better
productivity and less use of chemical control measures. For example
aphid resistant lucerne varieties.
•
When sowing use direct drilling rather than a cultivated seedbed, to
avoid damaging soil structure and causing erosion.
•
Use computerized grazing management tools to make optimum
decisions.
•
Education and skills updating of managers so they are able to select
the best management strategies in a situation.
Part 1: Growing food for cattle
45
Exercises – Part 1
Exercises – Part 1
Exercises 1.1 to 1.2
Name: _________________________________
Exercise 1.1: Grazing oats experiment
Present your experiment as a formal report.
Language
Try to use correct language and not slang.
When you are writing about something you have done; avoid writing
I did this..
Use the style called third person, and write instead
this was done..
as if you watched somebody else doing it. A good way to check if you
are doing this correctly is that the word I should not appear in your report
at all.
If you are still not sure about the type of language you are expected to
use, then read through some published experimental reports or talk to
your teacher.
Aim
The aim should be a short statement about the hypothesis that the
experiment is testing.
_________________________________________________________
_________________________________________________________
_________________________________________________________
46
Cattle production
Method
The method should clearly show how the experiment has been set up.
You may find a diagram is helpful. Include a description of how
experimental design principles are used.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Part 1: Growing food for cattle
47
Results
Present your raw data as a table and a graph.
48
Cattle production
Discussion
This is the main section of the report, where you can show your
understanding by using critical analysis and drawing out the implications
of the experiment.
•
Outline what your results show. Interpret the results. Are the results
showing what you expected? If not, why not?
•
Discuss how effective your experimental design was, and suggest
how it could be improved in future experiments of the same kind.
Include both the good and bad aspects of your experiment.
•
Compare your results to the expected results. Include discussion of
why your graph is, or is not, the same as the graph of vegetative
yield and density in the answers section.
•
Draw out the implications of the experimental results on
management practices in agriculture. Include the economic
implications of your findings.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Part 1: Growing food for cattle
49
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
50
Cattle production
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Conclusion
The conclusion should be a short statement that summarises what you
found out by doing the experiment with regard to the original aim.
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Part 1: Growing food for cattle
51
Exercise 1.2: Wallaby grass
1
Identify the benefits of Wallaby grass for the environment.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
2
Outline the most important of the benefits of using wallaby grass in
agriculture.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
3
Identify two major barriers to the domestication of a native grass.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
4
52
Produce a fact sheet that briefly provides the important information
on how best to establish and manage domesticated wallaby grass.
Use point form, you do not need to use full sentences. Include
subheadings to break up the information.
Cattle production
Fact Sheet: Establishment and
management of domesticated
wallaby grass
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
_________________________________________________________
Part 1: Growing food for cattle
53