Agriculture Reference
In-Depth Information
sunlight will be available for your plants
and all plants need light (see page 5).
A southern hemisphere site that faces the
north will get maximum sun, as will a south-
facing one in the northern hemisphere.
Landscape sites that face away from the
equator, south in the southern hemisphere
and north in the northern hemisphere, will
be shadier. An easterly aspect exposes plants
to the gentle morning sun, while those
plants facing the west will get the full blast of
the day's hottest rays. Adjacent buildings and
plantings will also inf luence the levels of sun
and shade.
In urban areas, the built environment may
channel winds away from or towards your site.
They need to be considered.
Frost
Just as hot air rises, cold air sinks. The lowest
parts of a site will collect cold air that can
turn to frost. The base of a hill will be much
colder and frostier than a point halfway up
the slope as the cold air flows like a liquid to
the lowest point. These frost pockets should
be planted with species that cope well with
frost or cooler conditions - it is all a matter of
plant selection. In warm areas where there
may not be enough chilling hours for some
fruit trees (e.g. apples), this low point in the
topography can be utilised.
Consider your plants' requirements for sun,
heat and shade and plant them accordingly.
Elevation
Elevation, or the height that the site is above
sea level, will also influence the climate. The
higher above sea level, the cooler the site will
be with more likelihood of frost compared to
the surrounding area.
Masonry walls and paving can store the day's
heat, especially if these face the equator or
west. This heat will be released at night,
warming the surrounding air and reducing
the chance or severity of frost. Swimming
pools or large ponds will also store heat that
will influence the night temperatures around
them.
Topography-windandfrost
The shape of the land will also influence its
climate in relation to prevailing winds, wind
tunnels and frost pockets.
Soil
Soil is that amazing material that supports
plant life. Plants take the majority of their
nutrients from the soil solution. This solution
is the water in the soil that carries dissolved
minerals and nutrients that in natural systems
are derived from the soil itself and any
fertilisers or organic matter added to it. The
quality of the soil to a large extent influences
the quality of the soil solution.
Wind
Planting on top of a hill will expose plants to
every wind that blows, while planting on the
leeward slope away from prevailing winds will
give some shelter. Strong winds are
destructive forces that strip leaves of moisture,
making plant establishment difficult. Your
site might need the planting of windbreaks
before any general planting can commence.
In hydroponic systems, where plants are
grown without soil, plants grow using the
