NCEA Level 1 Agricultural and Horticultural Science (90160) 2007 — page 1 of 3
Assessment Schedule – 2007Agricultural and Horticultural Science: Describe the
environmental impact of primary production management (90160) Evidence Statement
Q
One
(a)
(i)
(ii)
Evidence
Positive management practices
A Wind machine – mixes the air above the
orchard so that frost cannot settle.
C Trees on hill – prevent the hillside from
slipping / erosion.
F
Composting – decomposing plant and
animal material which can be returned to
the soil.
A
C
F
Negative management practices
B Overstocking – large stock-numbers can
quickly erode the topsoil if there is
insufficient pasture cover.
D Spraying grapes – spray can be blown onto
neighbouring properties and leached
through the soil.
E Cattle in river – cattle tend to urinate in
water so will contaminate the river. They
also pug up the banks of rivers, thereby
increasing the likelihood of erosion.
(ii)
B
E
Overstocking – reducing the number of
stock will reduce the likelihood of erosion.
Running large numbers of stock in a small
area could be viable if the ground cover is
adequate (which on this hillside is not).
Spraying grapes – using plants that are
resistant to pests and disease, or using
biological controls would reduce use of
inorganic chemicals, and hence reduce soil
/ water pollution.
Cattle in river – using riparian buffer zones
along river banks would ensure purity of the
water and allow water-life to thrive. Bridges
are needed to allow for stock movement
resulting in no effluent / waste.
Achievement
with Merit
Correctly
describes the
positive
environmental
impact of ONE
of the selected
management
practices.
Wind machine – better than using frost pots
or burning material as it does not pollute the
air.
Trees on hill – terracing the hillside is really
the only other practical method but it
involves large earthworks and greatly
modifies the landscape.
Composting – helps return nutrients to the
soil and improves soil structure. The
nutrients are organic and less likely to be
leached as inorganic fertiliser can be.
(b)
(i)
D
Achievement
Explains why
ONE of the
selected
management
practices has
less impact than
another method.
Correctly
describes the
negative
environmental
impact of ONE
of the selected
management
practices.
Correctly
explains, for
ONE selected
management
practice, how
another practice
could be used
which would
have less
environmental
impact.
Achievement
with Excellence
NCEA Level 1 Agricultural and Horticultural Science (90160) 2007 — page 2 of 3
Q
Two
(a)
(i)
(ii)
(b)
(i)
(ii)
Evidence
Effect on waterways of removing water for
irrigation

Reduces the volume of water flowing
down the river, diminishing the habitat
for water-life.

Reduced volume causes a reduction in
the speed of the water, which increases
the probability of stagnation and some
parts of the river may dry up.

Low river levels means the water will be
warmer, encouraging algae bloom
Achievement
Correct
description.
Achievement
with Merit
Correct
explanation.
Must have a
scientific link to
how the
environment is
affected
Why the effect on waterways is a problem

With reduced water flow, O2 will be
reduced, fish / plant / animal numbers
will decline; aquatic life / ecosystem is
degraded.

Many properties use bore water, which
is adversely affected by droughts and
when too much water is removed for
irrigation. Leaching can occur, resulting
in contamination of drinking water.

Lowering the ground water levels could
encourage increased leaching of
chemicals from pasture into rivers.
Possible actions to reduce farmers’ need to
irrigate

growing drought-resistant crops

storing water during the winter in tanks,
dams etc

reducing stock numbers over summer or
storing feed

adding organic matter

irrigating at night.
Growing drought-resistant crops

Crops such as lucerne, which has a
deep taproot, tolerate dry spells whilst
still providing quality feed.
Storing water during the winter

Using a dam to store rainfall during the
winter is an alternative to taking water
from local rivers. This depends on the
topography of the property.
Reducing stock numbers or storing feed

Reduced stock numbers cause less
demand for feed, which then reduces
the need to irrigate.

Make and store feed when the growing
is good to supplement during summer.
OM

Organic matter increases the water
holding capacity of soil and reduces
evaporation.
Correctly
describes ONE
suitable action.
Correctly
explains how
ONE action
would reduce the
need to irrigate.
Needs to have a
clear link to
conserving
water, ie not
using ground
water, but storing
rain water when
it is plentiful
Achievement
with Excellence
NCEA Level 1 Agricultural and Horticultural Science (90160) 2007 — page 3 of 3
Irrigating at night

This reduces evaporation, as would
irrigating on still days.
Q
Three
(a)
(i)
Evidence
Achievement
Washing the effluent down drains
Achievement
with Merit
Achievement
with Excellence
Chooses settling
ponds or
spraying effluent
onto pasture and
explains the
impact of TWO
management
practices on the
environment.
Explains how
settling ponds
work and justifies
the use of
settling ponds as
the best
management
practice,
compared with
the other two
practices.
Correctly
describes any
ONE
management
practice.

Using water hoses, effluent from the
milking shed is washed down the drain,
which will flow into a local waterway.
Using settling ponds

Effluent is washed into large ponds,
which allow solid material to settle. The
liquid moves through a series of shallow
ponds which kill off micro-organisms,
and it is then released into a waterway
or paddock.
Spraying effluent onto paddocks

(ii)
Effluent is piped to an irrigator, which
sprays it over pasture so that it can act
as a fertiliser.
Best management practice: use of settling
ponds
Describes the
impact of ONE
management
practice on the
environment

Settling ponds remove pathogenic
organisms from the effluent, and the
sludge can be collected for use as a
fertiliser. While settling ponds do take
up a lot of space, the water that leaves
them is quite clean and can be safely
pumped into a river or used on the farm.

The problem with washing the effluent
down the drain is that it affects waterlife due to its high nutrient status. Algal
growth is promoted, removing oxygen
from the water. There is also the chance
that diseases will be spread via the
waterway.

Spraying the effluent on to paddocks
can help alleviate the problem of
nutrients being returned directly into
waterways and is relatively cheap.
However, on this property it is not viable
as the resource states that it has
excellent free draining soils. This will
leach too readily, and in doing so will
contaminate waterways and bores in the
same way as simply washing the
effluent down the drain.
Spraying effluent
justified against
the other two
only if it is
clearly explained
that it is treated
first.
Judgement Statement
Achievement
Achievement with Merit
Achievement with Excellence
3xA
Achievement plus
Merit plus
3xM
1xE