NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 1 of 12
Assessment Schedule – 2008
Agricultural and Horticultural Science: Analyse a primary production environmental
issue (90653)
Evidence Statement (Issue 2 starts on page 7)
Q
Evidence
Code
Achievement
Achievement
with Merit
Issue 1: The use of nitrogenous fertilisers in intensive primary production systems.
One
(a)
(b)
Negative environmental
implications
 Increased level of nitrates in
groundwater. This nitrate-rich
water becomes unsuitable for
human, and even animal,
consumption.
 Increased level of nitrates in
surface water (streams and
rivers). This causes an
increase in the growth of
nuisance weed and algae,
affects stream life, and
decreases water clarity.
 Clover content of pasture
may be diminished and the
effectiveness of clover to fix
atmospheric nitrogen
reduced.
eg, in detail
Increased levels of nitrates tend
to lead to a higher level of
discharge of N2O to the
atmosphere – especially from
wetland areas. This is a
significant greenhouse gas
implicated with climate change
and global warming.
Increased level of nitrates in
surface water (streams and
rivers) causes an increase in the
growth of nuisance weed and
algae. This decreases water
clarity, as seen in Lake Taupo
(2003 10.5m clarity, 1990 14m
clarity).
Economic implications
Positive:
The use of N-fertilisers can result
in a huge increase in plant growth
and hence improve productivity
and farm income.
eg, in detail
Negative:
The cost of fertiliser. N-fertilisers
like urea have become very
expensive to purchase (urea ~
$700/t in Feb 2007) and apply
(costs from $30/t upward).
A1 OR
M1 for
each
environmental
implication
Negative
environmental
implications are
explained in
general terms.
Negative
environmental
implications are
explained in
detail. This
includes specific
examples,
stated relevant
units and
values, or a fully
linked answer.
Economic
implication is
explained in
general terms.
ONE economic
implication is
explained in
detail. This
includes specific
examples,
stated relevant
units and values
or a fully linked
answer.
A1  3
M1  3
A1
OR
M1
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 2 of 12
Q
Evidence
One
Negative social implications
 The use of nitrate-rich water
for human consumption
carries the risk of bottle-fed
infants developing
methaemoglobinaemia / blue
baby syndrome. This
condition causes breathing
difficulties and is potentially
fatal.
 Water resources, once
contaminated, may take
years to clean up – limiting
land use options and
potentially the ability to carry
out certain farming
operations on areas supplied
by the contaminated water.
 Other users may be affected
by nitrogen contamination
occurring upstream, eg a
mussel farmer may not be
able to export shellfish
because bacterial / algae
conditions in the water have
become excessive due to the
activities of farmers
upstream.
 The use of surface water
(streams and lakes) for
recreational purposes
(swimming, fishing, etc) is
adversely affected should it
become excessively
contaminated and be high in
nitrates and algae.
 In attempting to clean up the
water resource, authorities
may, under the Resource
Management Act, stipulate
the types of farming activities
that can be carried out in the
catchment areas of specific
bodies of water. This can
have significant impacts on
local communities, eg the
proposed strategy to improve
water quality in the Rotorua
lakes and Lake Taupo.
eg in detail
The maximum allowable value for
nitrate is 50g/m3. That is
equivalent to 11.3mg/L nitrate-N.
(c)
Code
A1
OR
M1
Achievement
Negative social
impact is
explained in
general terms.
Achievement
with Merit
Negative social
impact is
explained in
detail and
explanation
includes specific
examples and /
or stated
relevant units
and values.
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 3 of 12
Q
Two
(a)
(b)
(i), (ii)
(c)
(i), (ii)
Evidence
Potential courses of action for
producers to minimise the
negative environmental impacts:

Reduce the use of
nitrogenous fertilisers in
farming systems.

Apply N-fertilisers more
accurately to minimise
contamination.

Plant riparian margins
alongside waterways.

Select slow-release or RPR /
PAPR fertilisers.

Install denitrification trenches
between areas of high nitrate
levels in the ground and
waterways.

Use nitrification inhibitors like
eco-n.
See sample answers on following
pages.
Code
Achievement
Achievement
with Merit
Achievement
with Excellence
No judgement
required.
A2 for
each
strength /
weakness
explained.
Valid strengths
and weaknesses
are explained in
general terms or
limited information
/ detail provided.
A2  6
available.
Additional new
evidence from
Question Three
(justified
recommendation)
can be used for
strengths and
weakness
analysis if
required to award
A2.
OR
E2 for
each
strength /
weakness
comprehensively
explained.
E2  6
available.
A comprehensive
evaluation
requires valid
strengths and
weaknesses to be
explained and for
the assessment of
their relative
strengths and
weaknesses to
show depth and
breadth, which
may be
quantitative or
qualitative.
Note:
Additional new
evidence from
Question Three
(justified
recommendation)
can be
considered when
deciding whether
a comprehensive
evaluation of the
courses of action
has been made.
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 4 of 12
Two
Potential courses of action:
(b)
(i), (ii)
(c)
(i), (ii)
(1) Reduce the use of nitrogenous fertilisers in farming systems
(i)
Strengths
 The level of nitrogenous compounds entering the land / water is reduced.
 Less money is spent by the producer on fertiliser costs.
(ii)
Weaknesses
 Levels of production are likely to fall as the alternative nitrogen sources do not generally have
the ability to supply the high level of N-nutrients that fertilisers do.
 The improvement in environmental conditions is likely to be long-term / gradual, with little
immediate effect, due to the time it takes for high nitrogen levels in the soil to reduce to an
acceptable level.
(2) Apply N-fertilisers more accurately to minimise contamination
(i)
Strengths
 Losses via leaching, run-off and volatilisation are significantly reduced.
 Production is not significantly reduced / affected.
(ii)
Weaknesses
 There may be extra costs and time involved in implementing these practices.
(3) Plant riparian margins alongside waterways
(i)
Strengths
 These intercept a proportion of the N-nutrients that move from the soil system to the
waterway via surface run-off or shallow groundwater.
 There are other benefits to water quality in addition to reducing nutrients, eg lower water
temperatures, improved bank stability.
(ii)
Weaknesses
 Costs associated with the fencing, purchase of plants, planting and maintenance of the
riparian area.
 Loss of some productive land area.
 Loss of access to waterways / drains for operations such as cleaning.
(4) Select slow-release or RPR / PAPR fertilisers
(i)
Strengths
 N-nutrients are released slowly and at a rate that enables the plants to take up a much larger
proportion.
 These are less soluble and hence release their nutrients slowly over a greater period of time.
As a result, the potential for leaching and loss of N-nutrients from the root zone of the plant is
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 5 of 12
reduced.
(ii)
Weaknesses
 The initial plant growth response from these fertilisers is often less than for conventional
fertilisers.
 The price / kg nitrogen applied is greater than that for conventional nitrogenous fertilisers, eg
urea.
 Availability is an issue in some areas.
(5) Install denitrification trenches between areas of high nitrate levels in the ground and waterways
(i)
Strengths
 These deep trenches are filled with sawdust and are intended to mop up the nitrates in the
shallow surface water before it reaches the stream / lake.
 Have the potential to significantly reduce the amount of nitrogen entering a waterway via the
shallow groundwater pathway.
(ii)
Weaknesses
 Very expensive to install.
 Practical only over short distances and in locations where there is a hot-spot of nitrogen
contamination that the landowner is attempting to block off from the stream.
 Unproven in the field and in a range of soil types.
(6) Use nitrification inhibitors like eco-n
(i)
Strengths
 60% reduction in nitrate leaching.
 50% reduction in cation leaching (calcium, potassium and magnesium).
 75% reduction in nitrous oxide emissions (a potent greenhouse gas).
 10–15% increase in annual pasture production (results from trials at Lincoln University).
(ii)
Weaknesses
 The typical cost involved (June 2008) is $79/ha per application, excluding GST.
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 6 of 12
Q
Three
Evidence
Example
Use of nitrification inhibitors
Farming must be economically
sustainable, so farmers are likely
to consider actions that combine
optimum income with due
consideration given to improving
the environment. There is
evidence to support reducing
nutrient leaching by 50%. This
would need to be achieved
throughout New Zealand – in
different climatic conditions, soil
types and topography. The
financial cost of reducing
leaching is not excessive when
balanced against the higher
income derived from the use of
N-fertilisers. In comparison,
riparian strips are effective only
where creeks and streams flow
through paddocks. This is not the
situation in much of New
Zealand. The cost of fencing off,
planting, maintenance and loss of
productive land associated with
riparian strips could equate to the
cost of N-inhibitors. Their
effectiveness has not been
quantified, although the science
underpinning their use is sound.
Code
A3
OR
M3
Achievement
A
recommendation
is made.
Achievement
with Merit
In justifying their
chosen course
of action, a
candidate must
clearly:
select ONE
course of action;
explain the
reasons for
opting for it
compared with
the other course
of action;
AND
explain why the
other course of
action described
in Question Two
is not preferred.
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 7 of 12
Issue 2: The disposal of animal effluent from intensive primary production systems
Achievement
with Merit
Q
Evidence
Code
Achievement
One
Negative environmental
implications
 Increased level of nutrients
(especially phosphates and
nitrates) in surface water
(streams and rivers). This
causes an increase in the
growth of nuisance weed and
algae, affects stream life, and
decreases water clarity.
 Air pollution in the form of an
offensive smell when pig
slurry collected from growing
sheds on intensive
production units is sprayed
onto land.
 Chemicals, such as cleaning
agents used in dairy sheds,
can act as poisons to aquatic
plants and animals.
A1 OR
M1 for
each
environmental
implication.
Explains negative
environmental
implications in
general terms.
Explains negative
environmental
implications in
detail and the
explanation
includes specific
examples
and / or stated
relevant units and
values.
Explains
economic
implications in
general terms.
Explains ONE
economic
implication in
detail and will
include specific
examples
and / or stated
relevant units and
values.
(a)
A1  3
M1  3
eg, in detail
An average cow produces 20kg
of dung and 20 litres of urine per
day. Approximately 25 per cent of
this material is deposited in the
yard of a dairy shed. This waste
contains toxic levels of ammonia
and has a high biochemical
oxygen demand, both of which
decrease water quality.
(b)
Economic implications
Negative:
Dairy effluent systems cost
upwards of $20,000 to install and
require annual maintenance
costing between $2,000–$5,000.
eg, in detail
Positive:
The spreading of waste effluent
back onto land / pasture recycles
significant quantities of nutrients
back into the soil. Savings in
fertiliser costs are about $100–
$300/ha/yr.
A1
OR
M1
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 8 of 12
Q
Evidence
Code
One
Negative social implications
 Smell of effluent when
collected / dispersed on to
land.
 Water resources, once
contaminated, may take
years to clean up – limiting
land use options and
potentially the ability to carry
out certain farming operations
on areas supplied by the
contaminated water.
 Other users may be affected
by nutrient and coliform
contamination occurring
upstream, eg a mussel
farmer may not be able to
export shellfish because
bacterial / algae conditions in
the growing water have
become excessive due to the
activities of farmers
upstream.
 The use of surface water
(streams and lakes) for
recreational purposes
(swimming, fishing etc) is
adversely affected should it
become excessively
contaminated and high in
nitrates and bacterial
pathogens like E. coli.
eg, in detail
The maximum allowable value for
nitrate is 50g/m3, that is the
equivalent to 11.3mg/L nitrate-N.
Water resources, once
contaminated, may take years to
clean up – limiting land use
options and potentially the ability
to carry out certain farming
operations on areas supplied by
the contaminated water.
A1
(c)
OR
M1
Achievement
Negative social
impact is
explained in
general terms.
Achievement
with Merit
Negative social
impact is
explained in
detail and will
include specific
examples and / or
stated units and
values.
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 9 of 12
Evidence
Two
(a)
Potential courses of action for
producers to minimise the
negative environmental impacts:
Code
Achievement
Achievement
with Merit
Achievement
with Excellence
No judgement
required.
 Apply animal effluent directly
back onto pasture.
 Install advanced treatment
systems.
 Concentrate / compost
effluent and sell it as an
organic fertiliser.
 Cap stocking rates and / or
restrict farming types in
certain areas to limit the
potential production of effluent
and its impacts.
and
A2 for
each
strength /
weakness
explained.
(c)
(i), (ii)
A2  6
available.
(b)
(i), (ii)
See sample answers on following
page.
OR
E2 for
each
strength /
weakness
comprehensively
explained.
E2  6
available.
Valid strengths
and weaknesses
are explained in
general terms or
limited information
/ detail provided.
Additional new
evidence from
Question Three
(justified
recommendation)
can be used for
strengths and
weakness
analysis if
required to award
A2.
A comprehensive
evaluation
requires valid
strengths and
weaknesses to be
explained and for
the assessment of
their relative
strengths and
weaknesses to
show depth and
breadth, which
may be
quantitative or
qualitative.
Note:
Additional new
evidence from
Question Three
(the justified
recommendation)
can be
considered when
deciding whether
a comprehensive
evaluation of the
courses of action
has been made.
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 10 of 12
Two
Potential courses of action:
(b)
(i),
(ii)
(1) Apply animal effluent directly back on to pasture
(i)
 Recycling of nutrients in dung / urine means less money spent on fertilisers. At June 2008
prices, the nutritive value of effluent was ~$2,500/100 cows/year.
 Organic, and hence has appeal with many producers and consumers.
and
(c)
(i),
(ii)
Strengths
 Water content of the material can give some boost in times of low rainfall.
(ii)
Weaknesses
 Limits are placed by regional councils as to how much effluent can be applied on an annual
basis. Must not cause ponding or exceed 200kg N/ha/yr equivalent.
 Cannot apply when the soil is saturated, due to risk of run-off.
 Time lag and rainfall (or irrigation) required before cows will graze the pasture, due to the
effluent application.
 Smell is often a problem, especially with pig effluent.
(2) Install advanced treatment systems
(i)
Strengths
 Able to work in all weather conditions.
(iii) Weaknesses
 Require regular desludging and upkeep to operate effectively.
 Take up valuable land that could be used for farming operations.
 Loss of nutrients from the farm system.

Set-up cost is currently ~$30,000–40,000.
(3) Concentrate / compost effluent and sell it as an organic fertiliser
(i)
Strengths
 Provides an extra form of income for the farmer
 Nutrient content can be recycled and put to good use.
(ii)
Weaknesses
 Time and capital required.
 An option only for large producers or groups within a close proximity.
 Limited market that requires significant promotion in order to expand to the extent that a large
proportion of the dairy effluent can be accounted for.
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 11 of 12
(4) Cap stocking rates and / or restrict specific farming types in certain areas to limit the potential
production of effluent and its impacts
(i)
Strengths
 Puts a limit on the number of animals / effluent-producing operations allowed in a particular
area.
 Allows matching of an area’s environment and its ability to handle intensive farming with the
number of farms operating there.
(ii)
Weaknesses
 Huge economic impacts for both individual farmers and whole communities that are reliant on
particular effluent-producing farming operations.
 Requires an organisation and people to determine and enforce the restrictions – costs would be
significant.
Q
Evidence
Code
Three
Selection of the most appropriate
course of action from Question
Two (b) and justification of its
selection
Eg apply animal effluent
directly back on to pasture
This is the best option in terms of
minimising the negative
environmental impacts that result
from the disposal of animal
effluent.
The key advantage with this
option is that the nutrient content
of the effluent (be it cow, pig or
poultry) is able to be utilised and
recycled back into the soil –
saving the farmer money due to
reduced fertiliser costs and
promoting a healthy soil,
earthworms, decomposing
bacteria, etc). It is a relatively
low-cost option (dairy systems
are installed for around $15–20k)
and is a viable option for pig and
poultry operations, providing they
have access to a nearby farming
operation (eg sheep / dairy /
arable / market gardening, etc).
It has the extra advantage of
being an organically approved
activity.
While there are some issues with
the availability of suitable land
(flat, not saturated soils) and
neighbours who do not like the
smell, with careful management
these should be able to be
overcome or negated.
The other two options, restricting
farming operations and installing
A3
OR
M3
Achievement
A
recommendation
is made.
Achievement
with Merit
In justifying their
chosen course
of action, a
candidate must
clearly:
select ONE
course of action;
explain the
reasons for
opting for it
compared with
the other course
of action;
AND
explain why the
other course of
action described
in Question Two
is not preferred.
Achievement
with Excellence
NCEA Level 3 Agricultural and Horticultural Science (90653) 2008 — page 12 of 12
advanced treatment systems,
have significant weaknesses.
Restricting farming operations is
a hugely political option and the
implications for communities and
even the country’s economy are
significant. Policing it would be
difficult, and it is far better to farm
“smarter” with minimal
environmental impact than not
farm at all.
Advanced treatment systems are
the traditional means of dealing
with animal effluent but, at the
end of the day, the treated waste
still ends up in waterways,
causing elevated nitrogen and
phosphorus levels, eutrophication
and increased levels of
pathogens like E coli.
With the large numbers of large
dairy farms today, many of which
are irrigated, it makes much more
sense to spread the effluent back
onto the land.
Judgement Statement – 2008
Agricultural and Horticultural Science: Analyse a primary production environmental issue (90653)
Achievement
Achievement with Merit
Achievement with Excellence
Any 3  A1 / M1
3  M1
3  M1
Any 4  A2 / E2
4  A2 / E2
4  E2
1  A3
1  M3
1  M3
Note: Grades in brackets eg (A2) (E2) signal that evidence for another question in the paper has been
recognised.