Cotton

“Doesn’t cotton use a lot of water?”

When I told friends I was visiting a local cotton farm, I was consistently asked this question. Environmental messaging about cotton has pervaded the community consciousness. I was curious to find out how concerned I should be about this information. This is my first attempt at the topic. As always, it is limited by what access to data sources I have, and my skill set in understanding it.

Cotton history

The original source of cotton could have been East Africa and the Americas. What does seem certain is we’ve been using cotton for a long time. 5000+ year old cotton fabric has been found in Egypt, the Indus Valley (modern day Pakistan) and Mexico. Knowledge of cotton spread along with some of the key stories from our history books. Alexander the Great’s troops switched from woollen tunics to cotton when they invaded India. Muslims in Spain introduced cotton to Europe in the 8th century. Cotton became a valued import from India until the 18th century. Then the industrial revolution in the UK shifted production to Europe. There were poor work conditions in British mills and slavery in North American fields.

Cotton is a relative of the hibiscus plant. Most cotton grown today are Americas varietals, particularly Gossypium hirsutum; upland cotton. Pima and Egyptian cotton fibres come from a South American variety, Gossypium barbadense. It has fine, soft, long-staple fibers but is harder to grow.

Native Australian 'cotton'

Native Australian ‘cotton’ Kapok/Goonjan/Wanggu (Cochlospermum fraseri) in the Northern Territory. The fruits split to release numerous seeds on silky parachutes of a cotton-like fibre.

Cotton in Australia

In Australia, cotton came out with the first fleet. There are some native ‘cottons’, but they are not grown commercially. It puttered along as a minor crop in Queensland from the 1850s. This was unirrigated, marginal yield and poor quality. There are hints of an ugly story here too. Over 60,000 South Pacific Islanders were brought to develop the cotton and sugarcane crops. Was blackbirding involved?

The modern, irrigated crop we know was an innovation of the 1960s. Cotton was the first genetically modified (GM) crop to be grown in Australia in 1996. Today 98% of the Australian cotton crop is GM. CSIRO partners with Monsanto to breed cotton varieties suited to different regions in Australia. One of those varieties is Bollguard II. It contains two genes from the soil bacteria Bacillus thuringiensis (Bt). Those genes produce proteins in the cotton leaves, killing caterpillars of cotton’s biggest pest. Because of this, Australian cotton has the highest yields in the world. I have been unable to locate any organic cotton growers in Australia. It would appear that growing organic in Australia is commercially unfeasible.

The cotton growing season in Australia falls between September and April. Victoria’s season is shorter and finishes in late April or early May. The plant grows to about 1 metre tall. Lovely cream and crimson pink flowers give way to bolls. The bolls split to reveal cotton fibre inside.

Cotton bolls at different stages of opening

Cotton bolls at different stages of opening

During the growing season, fertilisers, pesticides and herbicides are applied to the crop. Once the cotton bolls open, defoliant is used before harvesting. This list breaks down the actions at each stage in more detail. This video shows the different stages (and machinery used) for cotton growing. It focuses on New South Wales, so some of the techniques are different to Victoria. Australian farms average 10 bales of cotton per hectare planted. Each bale contains 2,500kg of cotton lint, seed and vegetable matter.

Cotton’s environmental impact

Yes. Cotton uses a lot of water. About 7 megalitres per hectare; which grows at least 10 bales of cotton in Australia. A farmer told me that 40% of a bale is lint (cotton fibre), so that gives us about 10,000kg of cotton per hectare. Australia’s crop is considered the most water efficient in the world. So if water efficiency is important to you, Australian cotton is worth considering.

But should we be growing cotton in the first place? Cotton is a large water user when compared to other clothing fibres. So cotton as a clothing fibre doesn’t rate well for water concious consumers. But when compared to other crops grown where cotton is farmed? The story changes. Cotton uses less water than lucerne and tomatoes: popular crops in Victoria’s irrigated areas. Cotton is also a lucrative crop. From a farming perspective then, cotton makes the most out of available water allocations.

Speaking of irrigation, I wondered about the environmental impact of having an irrigation system. I spoke to Juliet Le Feuvre from Environment Victoria. I asked her if it’s possible to irrigate in an environmentally responsible way. She thinks it is, although we’re struggling to balance the competing needs well. She pointed me to the Murray-Darling Basin Plan for information on our current approach.

Lake Boga at sunset

Lake Boga at sunset, part of the Victorian Mid-Murray Storages.

Chemicals on cotton involve insecticides, fungicides, herbicides and defoliants. I’ll refer to these generally as pesticides. Insecticides are applied to stop insects destroying crop plants. Australia’s use of GM cotton varieties has reduced insecticide use by 85%. In 2010-11, that meant 0.54 kg of insecticide active constituent per hectare. Fungicides kill or prevent the growth of fungi and their spores. The only fungicides registered for use on cotton in Australia are for seed treatments.

Herbicides kill unwanted plants. Of all the herbicides used on cotton, more than 80% is glyphosate (Roundup). In 2013, herbicide useage was just under 3kg of active ingredient per hectare. Seven glyphosate resistant weed species occur widely in cotton farming systems. It’s interesting to note that irrigated systems provide higher weed control than dryland systems. Defoliants cause plant leaves to die back and drop off. This reduces the leaf and vegetable matter in the cotton when harvested. Defoliants could use chemicals that also have insecticide or herbicide qualities. Defoliation makes processing easier and maintains the quality of the fibre.

There are several concerns about chemicals:

  • negative effects on beneficial insects
  • weed resistance to herbicides
  • chemical run off and spray drift (when pesticides move away from their intended target).

Beneficial insects are being better supported by Integrated Pest Management Systems. This uses a broad range of strategies to control problem pests including targeted insecticides. Integrated Weed Management is helping control weed resistance. The cotton industry has significantly reduced the impact of pesticides on the environment. Tools like MyBMP will help the industry to keep doing so. But pesticides do continue to have an impact on waterways and vegetation.

Kilter Rural's cotton field

Defoliated cotton ready for harvest

Cotton on

Cotton is hard wearing and durable, but soft on the skin and hypoallergenic. It’s spun as a combed or mercerised yarn. Combed cotton is brushed, matte and low-twist. Mercerised cotton is treated with sodium hydroxide for a shiny finish and high twist. The fibre provides little insulation, high breathability and absorbs water. This is why its such a comfortable fabric in warm weather.

Most cotton is white; it can have shades of yellow depending on the variety grown. There are also coloured varieties of cotton in red, green and brown! Cotton fibres vary in length from 1 to 6.5 cm, with a diameter of 11-22 microns. Cotton fabric has good drape and high pilling resistance. The smoothness of the fibre defines stitches, good for showing off fancy stitch work. Mercerised cotton has superb colour retention.

Cotton is inexpensive, and can be washed and dried on regular machine cycles. It can help to lie the garment flat to dry, to avoid stretching it out of shape.

Cotton conundrums

Some high twist cottons, particularly mercerised ones, can knit on an angle. Cotton yarn is prone to splitting during knitting. Cotton’s good stitch definition shows up all your mistakes. That’s a concern for inexperienced knitters like myself!

Cotton fabric is inelastic, so it is prone to stretching and sagging. Blended yarns improve this tendency. Cottons dyed in dark colours tend to bleed. Adding vinegar to washes reduces colour running. The colours tend to fade in brushed cottons, they can also be prone to pilling. Be careful around flames, because cotton is highly flammable.

There is no easily sourced organic cotton available in Australia.

Where to see cotton locally

Kilter Rural – Lake Boga, Mallee region


Kilter Rural

I never expected to find cotton in Victoria. And yet there it was, a news article about the first cotton farm in the state for over 30 years. It is a single crop, but it has been successful. Farmers in the area are paying attention. The cotton is being grown by Kilter Rural, a specialist agricultural asset manager. In other words, investors buy the land, Kilter run the farm. I got in contact with Michael Neville, manager of agriculture at Kilter Rural to find out more. Michael brought me up to speed, revealing facts and statistics so quickly I could barely keep up with my notes.

Kilter are growing Bollgard II cotton, which is genetically modified (it’s the 71BRF variety). The plant is grown to hip height, then prompted to flower. A boll develops from each flower. Within the boll is the burr, which is the cotton fibre and seed. The plants are defoliated before picking so that the harvested cotton contains much less twigs and leaves. The cotton is harvested once the bolls have fully opened.

The harvested cotton is rolled into bales that weigh 2,500kg each. They’re so heavy a B-double truck can fit only 13 bales. Michael told me that Kilter need a 10 bale to the hectare harvest to break even. That’s a lot of cotton. The bales are driven to a cotton gin run by Auscott in Hay, NSW for the next stage of processing. Currently all ginned Australian cotton is sent overseas for spinning. There are no suitable yarn mills in Australia. Michael has some plans on how to change that, but they’re still in the beginning stages so we won’t see the results for a long time yet.

Kilter Rural's cotton field

Kilter Rural’s cotton field

The cotton is irrigated with a subsurface drip. 2016 was the third year that Kilter have grown cotton in Victoria. Their water usage over the three years tells the story of how they’re tweaking what they do. They used 10 mega litres of water per hectare in 2014, and reduced that by one mega litre in 2015. In 2016 they got it down again to 7 or 8 megalitres. The national average is 7.8 mega litres per hectare. Kilter Rural have been able to significantly reduce their insecticide use because of the variety of cotton they’re growing. The biggest change this variety of cotton brings is a significant reduction in insecticide use. The range of herbicides needed has also dropped.

Michael was happy for me to visit the farm, so we drove all the way up to Winlaton, near Swan Hill. Ron Opie, the farm manager showed us around. We arrived a few days before harvest. I’ve seen photos of cotton fields before, but seeing the real thing was different. The cotton was super white and practically falling out of its casing cotton. The plants were shorter, and there was more cotton per plant than I imagined. Kilter Rural grew 240 hectares of cotton this year, and aim to get to 500 hectares eventually.

Ron took us to the edge of the field, where some plants had germinated outside of the irrigation lines. Their growth had been slower, so he could show us a boll in the stages between closed and fully open. If the bolls are slow to open in the field, they use a horizontal bar to tap the cotton buds. This rap is enough to prompt them to release their fruit. At harvest time, a tractor will work 7 furrows at a time. It’s hooked up to GPS so the irrigation lines are unaffected.

Cotton bolls at different stages of opening

Cotton bolls at different stages of opening

Cotton doesn’t give Ron many problems, in fact his biggest issue is the irrigation lines. A worm likes to chew through the plastic tubes. Ron’s team have to plug the holes quickly to stop water loss! Kilter Rural rotate crops. There were corn husks on the ground from the previous crop when we visited. They have found that tomatoes grow well after a cotton crop. Ron explained how just before sowing, he’ll allow weeds to germinate. These are then turned into the soil, which gives the crop an advantage on weedy competition.

Kilter Rural participate in the Better Cotton Initiative. They value sustainability in their business and manage over 70 habitat hectares of remnant vegetation in the Victorian Riverina and Murray Fans bioregions. This covers grasslands, woodlands and scattered large old trees. Kilter Rural have also been involved in composting and carbon farming research projects.

This is the longest journey I’ve made visit a farm for this Fibreshed project, but it was well worth the trip. Plant farmers seem to be a different breed to animal farmers, much more laconic and business-like. It was great to meet face-to-face and better understand the work that’s occurring here.

Cotton plant in field, ready to harvest

Cotton, ready for harvest