Protected cropping: way of the future?

With food security and climatic variability global concerns, safe, sustainable protected cropping could be the way of the future. And Australian growers in this emerging horticultural sector are poised to profit.

Growing horticultural crops in protected facilities is a major agribusiness trend. Here, tomatoes grow in a vast glasshouse at Costa's major commercial facility near Guyra, NSW.

According to peak industry body Protected Cropping Australia (PCA), the indoor cropping sector is worth around 1.8 billion dollars at the farm gate per annum, equivalent to 20 per cent of the value of total vegetable and cut flower production in Australia (RIRDC report HSA-9A).

The sector employs more than 10,000 people directly across the country and is expanding at between four and six per cent a year, with an average return on investment of between five and 10 percent (and, for high-tech greenhouse vegetable enterprises, a potential ROI as high as 20 to 25 percent) per annum.

Farm gate prices for tomatoes in the most recent year for which ABS stats are available, 2012-2013, totalled $438.74 million; lettuces fetched $193.05 million over the same period. And we can assume that an increasing proportion of the salad vegies hitting the market originate from protected cropping enterprises.

Many of Australia’s most successful protected-crop growers are at the forefront of sustainable, efficient production, agricultural innovation, product safety and quality control.

Take Costa’s 30-hectare glasshouse enterprise at Guyra, Blush® Tomatoes, Australia’s largest such facility, which produces more than 12.5 million kilograms of vine-ripened tomatoes per annum and employs 600 people.

Costa's Senior Grower Keshav Timalsena inspects the crop.
Blush® Tomatoes


Here, Senior Grower Keshav Timalsena helps achieve record yields through innovative climate and water management, varietal selection, pest and disease control and biosecurity.

Guyra was selected for the region’s mild summer temperatures and sunny winters, which provide premium growing conditions for tomatoes and remove the need to heat or cool the glasshouses to compensate for external temperatures.

Water use efficiency at the facility is world-leading: just 12.5 litres of irrigation water is used to produce each kilogram of tomatoes (far less than the 100-200 litres per kilo required to grow field tomatoes). One-third of the greenhouse’s irrigated water is recirculated; another third is captured from the vast glasshouse complex roof.

Recirculation of fertilised drain water has halved the operation’s fertiliser usage, while sensors measure temperature, salt concentrations and water content to improve the efficiency of water and fertiliser use further.

Tomatoes grown in Costa's glasshouse require less water, fertiliser and pesticides, reducing costs and environmental pressure.

Costa employs automatically guided vehicles (AGVs) to pick the ripe tomatoes, virtually eliminating the need for staff to lift five-kilogram trays. ‘Clean’ propane fuel is used to heat the glasshouse, with the CO2 generated distributed into the glasshouse to reduce emissions and increase production.

Blush® Tomatoes has developed a CO2 mathematical efficiency model that’s boosted yield and reduced the facility’s CO2 emissions. Blush® also tests new tomato varieties for their suitability to Australia’s climate and market; researching the coating of greenhouse glass to increase yields; and looking at grafting’s effect on quality and yield.

In a world growing more and more concerned about food safety, quality and security, we can expect increasing demand for food grown in highly controlled environments such as Costa’s glasshouse complex.

The increasing incidence of extreme weather events – drought, high temperatures, wind and rain – and the growing scarcity of arable, pollution-free land land will likely be additional drivers of a global rise in protected cropping, as evidenced by the repurposing of computer-part factories in Fukushima as sterile hydroponic growing facilities in the wake of 2011’s nuclear power plant accident and consequent contamination of wide tracts of farmland.

In the US, Massachusetts Institute of Technology researchers are experimenting with growing crops in indoor, closed environments, and have successfully produced leafy vegetables in a 30-day cycle using LED lighting and both controlled hydroponic and aeroponic systems.

Protected cropping enables growers to exercise far more control over environmental conditions. As crops are protected from the elements, even extreme weather is unlikely to affect them. The need to use environmentally harmful chemicals such as pesticides, fungicides and herbicides to control pests, predators and weeds is greatly reduced.

Hydroponic lettuces are protected from the elements - and pests - in Ricardoes' glasshouses.
Merran White

As crops can be monitored closely, less fertiliser is needed, greatly reducing run-off and slashing fertiliser bills. Water consumption, too, can be reduced significantly, as much of the water used to irrigate protected crops can be re-claimed and recycled, minimising wastage and excess water costs.

Alternative fuels such as solar power or propane gas can be utilised for heating and other cropping tasks, if required, reducing energy requirements and the operation’s carbon footprint.  

Glasshouses can be set up to allow for automated watering and fertiliser application, harvesting and other routine tasks, while humidity, temperature and other variables can be monitored and controlled precisely, enhancing productivity and quality and enabling year-round production, cutting the use of costly, potentially harmful additives dramatically and reducing the need for a large labour force.

Australia’s rapidly growing protected cropping industry is keen to develop and utilise new technology such as that employed and developed at Costa’s tomato-growing facility to make further gains in quality, productivity and sustainability.

Indoor cropping is a growing global trend.

Protected cropping is not for the faint of heart or the light of wallet: it’s a capital-intensive business, with costs estimated by the PCA at between $100 and $300-plus per square metre, depending on the sophistication of the greenhouse and equipment, and viable production units a minimum of 1,500 square metres.

Despite the comparatively high set-up costs, a fresh-food-loving public here and abroad suggests there’s a profitable (and sustainable) future in quality greenhouse produce. In 2013-2014, ABARES/ABS statistics showed solid growth in export prices for salad vegetables (including greenhouse-grown truss tomatoes and lettuces) compared to the previous financial year.

The export value of ‘salad vegetables’ also grew substantially over 2013-2014 – lettuce exports fetched $5.5 million last year, up $0.8 million from the previous financial year, while tomato exports were up $4.1 million to a healthy $13.5 million.

*Hydroponics, the production of crops in isolation from soil, with their total water and nutrient requirements supplied by the system, enables recirculation or ‘free drainage’ of nutrients for re-use on other crops or vegetation, and is highly efficient in its use of inputs: water, fertilisers, land, energy and labour.


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