Fertiliser
- Erosion Management
- Fertilisers and soil ameliorants
- Fertiliser application methods
- Fertiliser application rates
- Use of mill by-products
- What are the effects of fertiliser overuse?
- Managing saline and sodic soils
Fertilisers and soil ameliorants
Fourteen essential nutrients are required to produce healthy cane. Nutrients that are absent
or low in concentrations need to be added by applying fertiliser. Fertiliser rate recommendations
are shown in Schedule 1 (page 24 & 25).
Fertiliser application methods
Calibrate your fertiliser applicator each time you change the product you are applying.
Where feasible, apply fertiliser below ground,either stool split or directly beside the stool (no
more than 600 mm from the stool). Placement at the centre of the inter-row is not recommended.
If fertilisers are applied on the surface, you should delay application until the cane has
reached 50 cm in height. Surface banding of fertiliser is most effective when applied close
to the stool.
After completing surface application of fertiliser, apply 20-25 mm of overhead irrigation, or
apply within 48 hours of a strong possibility of rain showers.
If you use furrow irrigation, apply all fertiliser sub-surface unless it can be incorporated prior
to irrigation.
If you apply your fertiliser via trickle irrigation, use no fewer than three split applications of
nitrogen.
Biosolids (treated sewage sludge) from urban sewage treatment plants may be used as a source of nitrogen and organic matter. Guidelines
for use are currently being developed by the DNR and CRC Sugar.
Fertiliser application rates
Carry out regular analytical testing of your soils to determine their nutrient status
Use the results of this soil testing to:
• ensure that the quantities of fertiliser you apply are matched to crop needs; and to
• determine whether nutrient leaching could be occurring.
Do not over apply fertilisers. Excessive nitrogen fertiliser application rates may lead to wasteful
losses through:
• volatilisation and denitrification to the atmosphere;
• run-off in water; and
• leaching through the soil profile into underground aquifers.
These losses may have negative impacts elsewhere in the environment.
Use of mill by-products
Recycling and reuse of mill mud (filter cake) and boiler ash from sugar mills can provide
plant nutrition and soil improvement benefits.
Recycling supports the principles of ecologically sustainable development.
Sugar mills can give advice on typical nutrient composition, application rates and yield response
data for mill mud and boiler ash
What are the effects of fertiliser overuse?
Loss of fertilisers, particularly nitrogen and phosphorus, from the farm through run-off
or leaching can have negative effects on the surrounding environment including:
• acidification of the soil profile;
• increased algal growth in watercourses and downstream; and
• contamination of groundwater.
It is in your best interest, both from an environmental and financial perspective, to
minimise fertiliser loss from your farm.
Matching fertiliser rates to crop needs is an important first step.
Tailwater recycling pits and artificial wetlands reduce the movement of nutrients
off-site.
Stream bank vegetation can also act as a buffer, trapping sediment with attached
phosphorous and extracting nitrates from ground water
Managing saline and sodic soils
What are saline soils?
Saline soils are those in which the concentration of soluble salts in soil water is
sufficient to restrict plant growth. These salts can be a combination of calcium,
magnesium, sodium or potassium ions in association with chloride, sulfate, carbonate
or bicarbonate ions.
What are sodic soils?
Sodic soils occur where sodium represents more than 10-15% of the elements attached
to clay particles. Sodic soils may or may not be saline. Saline soils are usually
also sodic.
The following techniques may prevent the development of saline and sodic soils or aid in
their management:
• ensure that drainage schemes in potentially saline areas are coordinated across the catchment
to minimise the effect of discharge of saline water;
• soil ameliorants such as gypsum should be
applied;
• where practicable, retain harvesting residue to reduce soil sodicity;
• maintain an adequate topsoil layer to prevent subsoils (B-horizon soils) being exposed as a
result of levelling or clearing;
• where subsoils are exposed during levelling, a topsoil layer should be returned;
• adopt good irrigation management practices to prevent rising water tables. CRC Sugar is currently developing a tool kit for
the identification and management of sodic soils.
Are you using best practice fertiliser management?
Soil tests taken and records kept
Advice obtained on fertiliser needs
Potential for off-site losses minimised
Fertiliser buried or incorporated if surface applied
