how to plant sugarcane

Meet farmer Joe. He is one of the thousands of farmers in Australia who grow sugarcane. He's going to tell us about how sugarcane is grown, processed, and used.


Where does sugar come from
In Australia, sugar is made from the juice of a giant tropical grass called sugarcane. Sugar is produced in over 100 countries around the world.  About 70% of sugar is produced from sugarcane, and the remaining 30% from sugarbeet, a root crop resembling a large parsnip grown mostly in the temperate zones of the northern hemisphere. 
How does a sugarcane plant make sugar?


Sugarcane itself looks like bamboo stalks and it is in the stalks that the plant stores energy that it doesn’t need straight away – rather like animals store fat. 

Sugar is actually made in the leaves of the sugarcane plant by a natural process called photosynthesis and then the sugar is stored as sweet juice in its stalks.

Photosynthesis is when the plant takes in carbon dioxide from the air though pores in its leaves and absorbs water through its roots. These combined to make sugar using energy from the sun and with the help of a substance called chlorophyll. Chlorophyll is green which allows it to absorb the sun’s energy more readily and which, of course, gives the plants’ leaves their green colour.  The sugarcane stalks are harvested and converted into raw sugar.

Where is it grown in Australia?

Sugarcane production hugs coastal hubs along 2,100 kilometers of coastline between Mossman in far north Queensland and Grafton in northern New South Wales.



Planting
Sugarcane is grown by replanting part of a mature cane stalk. Farmers cut some of the fully grown cane stalks into lengths of about 40 centimeters called "setts".

The setts are planted by special machines, which drop them into furrows, add fertiliser and cover them with soil.

Growing

Sugarcane needs strong sunlight, fertile soil and lots of water (at least 1.5 metres of rain each year or access to irrigation) to grow. After a few weeks new shoots grow from buds on the joints of the setts and break through the surface of the soil. Up to 12 stalks grow from each sett, forming what is known as the stool of sugarcane.

A crop of cane takes about 9-16 months to grow in Queensland. In northern New South Wales (where it is cooler) it takes 18-24 months to grow. Typically, a cropping cycle comprises one plant crop and 3-4 ratoon (regrowth) crops. When ripe, the cane is usually about 2-4 metres tall
Harvesting

During harvest, the cane harvester drives along each row and cuts the cane stalk off at the bottom of the plant. The long stalk is then cut into many shorter lengths called ‘billets’ (around 30cm). Another machine known as a cane haulout drives alongside the harvester, collecting all the billets.

Australia’s sugarcane is harvested during the drier months in tropical climates – between June and December each year - depending on the weather.
Getting the cane to the mill

Once sugarcane has been harvested, it must be transported to a sugar mill as soon as possible. The longer it takes, the more sugarcane juice stored in the stalks will evaporate - so it is important that it arrives within 16 hours of being cut, to minimise deterioration.

The cane haulout collects billets until its full, then drives across the paddock to the road, where it unloads its contents either into a semi truck (for road transport) or mill bins at local sidings on the nearest railway track (for train transport). The industry maintains a network of nearly 4000 km of narrow-gauge rail lines to get cane from the paddock to the mill quickly and cost effectively.

Milling into raw sugar

Sugar mills crush and wash the juice from cane stalks and separate as much sucrose as possible from the water, impurities, fibre and dirt that comprise the rest of the cane juice.

Weighed & recorded: When the sugarcane first arrives, computerised cane transport scheduling systems enable cane movements to be continually monitored. When the cane arrives at a mill it is weighed and processed at automatic cane-receiving stations.

Chopped & shredded: The billets (short pieces of canestalk) are tipped onto a cane carrier for transport to a shredder, which chops and shreds the cane into fibrous material and ruptures the juice cells.

Crushed: It is then crushed by large rollers. Firstly, pairs of rollers feed the cane through a series of mills comprising three large rollers arranged in a triangular formation. This separates the juice from the fibrous material, which is called bagasse, which is used as fuel to run the mill’s boiler furnaces.

Heated & cooled to make crystals: The juice is pumped away for processing into raw sugar. It is cleaned to remove impurities and thickened into a syrup by boiling off excess water. It is then seeded with tiny sugar crystals in a vacuum pan and boiled until sugar crystals have formed and grown. These crystals are separated from the molasses around them in centrifuges that are like giant spin dryers. The crystals are then tumble-dried and stored in large bins until they are to ports.

Refining (from ‘raw’ to ready to eat)

Australian mills produce ‘raw’ sugar, which is an intermediate product which then needs further refining before it becomes suitable for human consumption, or used as an ingredient in the manufacture of food and beverages.

At the refinery, the raw sugar crystals are washed and dissolved in hot water. Carbon dioxide and lime are added to the melted sugar to remove any remaining impurities. The sugar is filtered through cloth, then the remaining colours and impurities are removed and the pure sugar is boiled in a vacuum pan and seeded with fine sugar crystals. When the crystals are large enough they are tumble dried to remove moisture. The dried sugar is then graded into sizes ready for delivery to customers.

Australian refineries process around 20% of Australia’s raw sugar into white (refined) sugar and liquid sugar products and other specialty products such as Golden Syrup, treacle, coffee sugar and cube sugar.

80% exported overseas

Around 80% of Australia’s production is exported overseas as ‘raw’ sugar, where it is further processed.

Raw sugar is stored at bulk sugar terminals before being sent to refineries. Queensland’s bulk sugar terminals can store more than 2 million tonnes of raw sugar, allowing year-round deliveries to refineries in Australia and overseas. Queensland bulk sugar terminals are located at Cairns, Mourilyan, Lucinda, Townsville, Mackay, and Bundaberg.

Since 1964 all raw sugar in Australia has been handled in bulk. Bulk sugar is transported from the mills in containers by road or rail to the terminals, where it is carried by conveyor into the storage shed. When a ship arrives it is filled quickly via conveyors.

Australia is the world’s second largest exporter of raw sugar after Brazil. We sell mainly to East Asia, China, Indonesia, Japan, Korea, Malaysia and New Zealand. Australia has an international reputation as a reliable producer of high quality sugar.
Products
By-products from mills are recycled, adding to the efficiency of the milling process.

Other by-products include residue which can be used as a fertiliser on cane farms and gardens, and specialised inputs which can be made into plastics, clothing and pharmaceuticals.

Molasses is a dark syrup separated from raw sugar crystals during the milling process. It is used as a raw material for ethanol and rum. It can also be used for animal feed.

Why do we eat sugar? 

Why do we eat sugar?

People like sugar for its sweetness and the energy it provides, so farmers grow sugarcane commercially in Australia to extract the sugar. It is a natural sweetner.
Sugar nutrition: energy in, energy out
Sugar plays an important role in providing the energy necessary for our bodies to function properly.

Sugar is a type of carbohydrate. Other carbohydrate-rich food includes breads, cereals, fruit, rice, potatoes, legumes and pastas. Carbohydrates are the body’s preferred energy source.

During digestion, all sugars (and other carbohydrates) are broken down into simple sugar, glucose, which then travels through the blood stream to body cells. There it provides energy or is stored, as glycogen, in muscles or the liver for future use.

The key is to balance energy inputs (what we eat) with outputs (the energy we use) while recognising the importance of taste (treats we like) and nutrition (what’s good for us).

Since sugar has half the calories of fat (1 teaspoon of sugar contains only 20 calories where as 1 teaspoon of fat contains 45 calories), and gram for gram sugar is less fattening. In fact the most recent research indicates that people who eat moderate amounts of sugar are less likely to eat as much fat, and vice versa.

Source: SugarCane