Sugarcane

24.05.17

Sugarcane (Poaceae Saccharum) is a tall tropical perennial grass that grows to between 2-4m high. Sugarcane is used to produce a range of food products including sugar, molasses and golden syrup. The biofuel ethanol can also be produced from sugarcane which can be used as a fuel for vehicles in its pure form but is usually blended with gasoline to improve vehicle emissions.

Overview

Sugarcane is one of Australia’s largest crops and accounts for a significant percentage of the crops produced in Queensland’s coastal agricultural production areas. The first Australian fields were established in Queensland in the mid-19th century; since then the Australian industry has grown to become one of the world’s largest exporters of raw sugar along with Brazil, the European Union, Thailand and the United States. Australian production of sugarcane is around 35 million tonnes per year. The main product of Australian sugarcane is raw sugar of which about 80 per cent is bulk exported.

The Australian industry is well established with a proven production and marketing system. The locations in which it can be grown are limited by climate, reliable water (rainfall and/or irrigation) and proximity to processing mills. This generally limits the production to tropical climates along coastal areas where there is reliable rainfall or irrigation water resources.

Sugarcane is predominantly grown along the northeast coast of Australia, throughout Queensland and northern New South Wales. There are around 4,000 cane farming enterprises in Australia. These supply 24 mills that are run by seven milling companies. The major product in Australia is raw crystal sugar; this is sold to refineries both domestically and internationally.

There are several organisations representing sugarcane growers in Australia. Canegrowers is the national peak body for sugarcane growers; as well as a national office they also have regional branches. The Australian Cane Farmers Association is a member based organisation representing sugarcane farmers. Sugar Research Australia is the industry research and development corporation that funds and manages research, development and extension (RD&E) projects that drive productivity, profitability and sustainability for the Australian sugarcane industry. Sugar Research Australia is funded by a statutory levy applied to growers and millers per tonne of sugarcane.

Facts and figures

  • Sugarcane is predominantly grown in Queensland, accounting for 95% of the national production
  • More than 80% of all sugar produced in Australia is exported as bulk raw sugar
  • Sugar is the second largest export crop in Australia after wheat with a total annual revenue of around AU$2.5 billion
  • Areas where sugarcane can be commercially produced are limited by climate, water resources and proximity to a processing mill

Production status

Australian sugarcane production averages around 35 million tonnes with the bulk grown in Queensland.

There are around 4,000 cane farming enterprises in Australia.

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Map of current and potential growing regions

Uses

The main product of sugarcane is raw sugar, made from the juice of the cane, and molasses which is a by-product of the sugarcane refining process.

Ethanol can also be produced from sugarcane, which is an alcohol made by fermenting the sugar and starch components of plant materials using yeast. Ethanol can be used for food products but is also used as a biofuel.

Bioethanol can be used in its pure form but is commonly added to gasoline to reduce vehicle emissions. There are three ethanol refinery facilities in Australia located in Queensland and New South Wales, however only one of these, in Queensland, processed molasses derived from sugarcane to produce ethanol.

Production Requirements

Growing regions

Sugarcane is predominantly grown along the northeast coast of Australia, throughout Queensland and northern New South Wales. Around 80% is grown north of the tropic of Capricorn.

Sugarcane must be grown within the transport network of a sugar mill as the juice in the cane stalk will start to evaporate after about 16 hours, reducing the juice yield and price paid to the farmer. The low value/high biomass nature of the crop also makes long distance transport uneconomic.

Soil type

Sugarcane can grow on a range of soil types from sandy to clay soils but grows best on fertile, well-drained soils with an ideal pH of 6.5, however it can tolerate a degree of acidity or alkalinity and is moderately sensitive to soil salinity.

Crops grown on poorer quality soils will require greater physical and financial inputs due to increased irrigation and fertiliser requirements.

Soil sampling is recommended prior to planting, to gather information about the chemical and nutrient properties of soil within a particular paddock or field. This can identify any actual or potential nutrient imbalances or deficiencies and be used to develop crop nutritional requirements (fertiliser regimes).

Climate

Sugarcane requires a warm, sunny, frost-free climate. It grows in direct proportion to the amount of water available, as a general rule for each 10mm of soil water used, one tonne of cane per hectare is produced. However, excess water can result in waterlogging which will reduce yield.

Sugarcane can be grown as an irrigated or non-irrigated crop but requires at least 1,100mm of rain per year or equivalent water from irrigation. Non-irrigated sugarcane is mostly grown along the coastline where there is higher rainfall. Soil temperature is critical for cane to sprout, relying on accumulating temperature days 18˚C or above.

Varieties

Variety selection is based on a number of considerations including: suitability of the variety to environmental conditions (rainfall, elevation, temperature, soil type), sugar content, yield and disease tolerance and resistance. Beyond environmental and agronomic considerations, there are also business and farm profile/strategy decisions that contribute to the variety of sugarcane selected for any given year or paddock.

Generally, no variety will exhibit all the desired attributes for the site selected. Indeed, a single variety may perform differently on different soil types with different rainfall patterns. Varietal selection often comes down to balancing the various risk factors based on the range of considerations.

There is a wide range of sugar varieties for farmers to choose from. Individual research is required to determine the most suitable variety. Sources of further information on sugar varieties grown in Australia are:

Planting and crop management

There are a number of factors that contribute to a successful sugarcane crop including land preparation, planting time, planting material, planting operation, fertilising, soil moisture and cultivation. These factors can dictate the yield of sugarcane crops for up to five years.

Sugarcane can grow on a range of soil types and so land preparation may also vary, however, obtaining a suitable soil tilth is important. Most soils require only limited tillage to create a suitable seedbed. The soil preparation required will also depend on the planting equipment being used. If using improved planting equipment such as double-disk planters, minimal tillage, may be required.

Sugarcane is a vegetatively propagated plant and a crop can germinate two ways: planting setts and then for up to four subsequent crops by ratooning. Planting is considered the most expensive part of the sugar cane production system and the most important, as good establishment is one of the most crucial factors for a good crop. Sugarcane is grown by replanting part of a mature cane stalk. The fully grown cane stalks are cut into lengths of about 40cm called “setts”. Setts may need to be treated with fungicide and insecticide sprays to ensure they are disease free. Hygiene is critical for planting sugarcane; planting material and any machinery must all be treated appropriately to ensure disease-free planting.

Germination is sensitive to temperature and although varieties vary in their degree of sensitivity to temperature, sprouting relies on accumulating temperature-day units and, as a general rule, cane should not be planted when soil temperatures are below 18˚C as germination will be very slow. Germination rarely occurs at temperatures below about 11˚C.

Row spacing and planting density can vary. The industry standard for row spacing is 1.5m, however there has been a tendency for growers to move to move to wider rows that more closely match the width of machinery. One of the important considerations for crop row spacing is to account for machinery access. Matching crop row spacing to equipment wheel tracks can reduce compaction near the crop row and could lead to higher yields, better survival of stools and longer ratoon cycles. Cane is planted using machinery that drops the setts into furrows (40-65mm deep), adds fertiliser and then covers the setts with soil. After a single planting, up to four subsequent crops can sprout from the stools remaining in the ground after harvest, a process called ratooning.

The estimated seasonal water requirements for a high yielding sugar cane crop are between 1100-1500mm/ha over the growing season supplied through natural rainfall and/or irrigation. Under irrigation, water is provided on an as needed basis and soil moisture and/or crop monitoring equipment can be used to support watering decisions. For further detailed information on irrigating a sugarcane crop, refer to Sugar Research Australia’s Irrigation of Sugarcane Manual.

Like any crop, production is optimised by good nutrient management. Nutrient management should take into account basic soil attributes such as colour, texture, position in the landscape, and chemical properties. Regular soil testing is often undertaken to support nutrient management decisions which should target yield and sustainability (maximising soil fertility on-farm and minimising off-site effects). Fertiliser and nutrient requirements will vary depending on the soil, but the main fertilisers used in sugarcane are NPK fertiliser (nitrogen, phosphorus and potassium) and if required calcium, magnesium, silicon and trace elements. If using irrigation, nutrients can be applied through the irrigation system (called fertigation). For more information on best practice nutrient management, refer to Sugar Research Australia’s Best–practice nutrient management.

The Sugar Advisors Information Kit, available from Sugar Research Australia’s website, provides advice for new growers including industry, agronomic and market information.

Weeds, pests, and diseases

Weeds can cause a number of problems for a sugarcane crop: competing for nutrients, sunlight and moisture; making harvesting difficult and reducing cane quality due to contamination; and some weeds can release compounds that are toxic to sugarcane growth.

The main weeds found in Australian cane fields are:

  • Grasses – generally prolific, germinate in the early stages of a cane crop and compete vigorously with the crop
  • Sedges – generally occur in wetter areas, the main sedge is nutgrass which is difficult and expensive to control
  • Broadleaf weeds – generally regional and soil specific
  • Vines – climb up and entangle themselves in the sugarcane, tend to germinate later in the season, can be difficult to control and manage, can impede harvesting and contaminate product leading to a lower price for the farmer

Methods used to control weeds in sugarcane crops are mechanical cultivation, herbicides, and the retention of post-harvest residues. A combination of these methods is usually used in an integrated management system. A challenge for the sugar industry and a management issue for growers is ensuring that there are no environmental impacts off-farm from the chemicals used. Herbicides must be applied by properly trained people and the appropriate safety procedures followed.

The major sugarcane pests are cane grubs, rats, solider flies, wireworms and nematodes. Control methods for these pests include poison and insecticide, reducing available food, and cultivation. For more detailed information on managing pests refer to Sugar Research Australia’s website page on pests.

Diseases affecting sugarcane crops in Australia include ratoon stunting disease, fiji disease, pineapple disease, pachymetra root rot, rust, orange rust, smut, leaf scald, yellow spot, chlorotic streak, top rot and mosaic. The most common methods for controlling these diseases include treatment of planting material, suitable farm hygiene to prevent re-infection, the development of resistant varieties, regular crop inspection, plough-out of diseased cane, rotating varieties to minimise the build-up of spores and quarantine protocols to monitor the transfer of equipment. For more detailed information on diseases and control methods refer to Sugar Research Australia’s website page on diseases.

Infrastructure Requirements

Large scale agricultural machinery, tractors, cultivation equipment, a planter, and boom sprayers are required to grow sugarcane. Harvesting requires a mechanical cane harvester and haul out tractors and bins.

Planting and harvesting services are generally carried out by contractors and these services must generally be secured and scheduled ahead of planting or harvest time.

Harvesting & Processing

A sugarcane crop will normally grow for around 9-16 months before it is harvested, this can extend to up to 18-24 months for cooler parts of New South Wales. The harvesting season usually runs from June to December, however factors like climatic conditions, ratooning characteristics and crop rotation practices can influence this timeframe.

It is harvested mechanically using a specialised harvester which is flanked by a haul out tractor. The haul out tractor collects the harvested cane and delivers it to cane bins on a tram track or to a truck for transporting to the mill. Ideally, sugarcane should arrive at the mill within 16 hours of harvesting or the juice in the cane stalk will start to evaporate reducing the price the farmer is paid for the sugarcane.

Upon arriving at the mill, the sugarcane is weighed and crushed. The price paid to the farmer is dependent on the amount of sugar produced from their cane which is a function of the amount of sugar cane produced per hectare and the sugar content of that cane.

The cane is processed at the mill by crushing and washing the stalks. The resulting cane juice is then processed to separate as much sucrose as possible from the water, fibre and dirt. Further processing produces raw sugar crystals and molasses as a by-product of the process.

The raw sugar is bulk exported or sent to refineries for further processing to produce sugar products such as white sugar, syrup, treacle and coffee sugar.

For detailed information on the harvesting process refer to Sugar Research Australia’s Harvesting Best Practice Manual.

Markets & Marketing

Sugarcane is supplied directly to a mill which a farmer has signed a contract with. The contract does not specify a certain volume, but commits the farmer to selling all their harvested cane to that particular mill. Some farmers may forward sell a percentage of their crop at a set price. This can be beneficial if the price of cane drops at the time of harvesting, however if the price increases to above the contracted price, then the farmer will only get the contracted price.

The price paid to the farmer is calculated using a cane payment formula which varies from mill to mill depending on the locally agreed and negotiated arrangements. The price paid to a farmer will be affected by the volume of sugar that is extracted from the cane (sugarcane quality) and the global price of raw sugar.

The mills then process the sugarcane to produce raw sugar and molasses which they then sell on for further refining to produce a range of sugar products, such as white sugar, coffee sugar and golden syrup or export.

There is one ethanol production facility in Australia using molasses as a feedstock. As this facility is using a by-product from the sugarcane mills, it does not present a direct opportunity for sugarcane farmers.

Risks & Regulations

Risks/challenges

Risk is inherent in all agricultural pursuits and some of the risks associated with cropping include:

  • most sugarcane is grown in regions prone to natural disasters such as flooding and cyclones. Should these events occur losses may be significant
  • the crop failing to establish or mature properly due to adverse weather events, thus resulting in reduced harvest tonnage and/or poor quality cane
  • commodity prices falling during the growth period impacting on the returns projected at planting
  • yields failing to reach expectations meaning production and capital costs are not recouped.

Regulatory considerations

The regulatory considerations that apply to all Australian agricultural farms, including laws applying to chemical use and management, occupational health and safety and transport (including machinery movements), apply to sugarcane operations.

With the proximity of many sugarcane growing districts to the Australian coast and waterways that feed into the ocean, there are regulations on the management of chemicals on-farm to ensure there is no environmental impact off-farm. The Reef 2050 Water Quality Improvement Plan and regional Natural Resource Management Plans have focussed attention on many farming practices, including those used for sugarcane, and their potential impacts on aquatic environments. In Queensland, The Environmental Protection Act 1994, provides to protect the environment under sustainable development. For the sugarcane industry this legislation governs the management of chemicals (including fertilisers) on-farm to ensure there are no off-farm effects, for example from run-off into waterways.

To manage the spread of pests and diseases, there is a biosecurity system in place in Queensland under the Biosecurity Act 2014.

To address environmental and regulatory concerns the Australian Sugar Cane industry has established a BMP program that bench marches grower practices against industry agreed standards and encourages continuous improvement. These practices aim to maximise production whilst minimising environmental impact.

Image Gallery

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Sugarcane crop

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Creating new varieties through cross pollination (source Sugar Research Australia)

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Young healthy cane growing well (source Sugar Research Australia)

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Green cane harvesting in the Mulgrave region (source Sugar Research Australia)