Agriculture Reference
In-Depth Information
Chemically produced fertilisers dissolve
rapidly into the soil solution and can 'burn'
the plants with an overload of nutrients.
The coated 'slow release' pellets will provide
nutrients over a longer period but can be
prone to 'dumping' their nutrients under
certain soil conditions with the same result.
Uncomposted manures can also be toxic to
plants as the nutrient levels are so high they
can also 'burn' the plants. Never use
uncomposted manures and be sparing with
powerful manufactured fertilisers. Adding
that little bit extra ' just for luck' can have
disastrous results, so always follow the
manufacturers' instructions.
chew their food as well as others, and for
this reason horse manure can harbour
unwanted weed seeds. In commercial
situations and monocultures where nutrient
levels need to be carefully monitored,
organic fertilisers may be too variable to be
used with confidence. However, in most
landscapes, using different sources of
organic materials will deliver a satisfactory
growth rate with the added bonus of
improved soil structure that will boost water
retention, drainage and the nutrient-
holding capacity of any soil.
Mineral fertilisers consist of various crushed
rocks and rock dusts that affect the pH and
nutrient levels in the soil. Ground limestone
and dolomite raise pH, as well as calcium
and magnesium levels, gypsum helps break
up heavy clays, and sulphur and iron acidify
soils making other nutrients more available.
The major advantage of composts and well-
rotted manures is that they also supply some
organic matter that will improve soil
structure (see page 9). Fertilisers derived
from organic sources also have the full
range of nutrients and trace elements in
varying quantities, unlike the manufactured
variety. This makes them simple to use in
domestic and small-scale biodiverse
contexts, though weed seeds may also
abound. Be aware that some animals do not
A successful landscape will only
eventuate with a sound knowledge of the
site and soil conditions and by selecting
plants that thrive in that environment.
