Focus on the reef
Paper presented by Matt Kealley at the QFF conference: An ongoing perspective on how industry is balancing the objectives of reef health and growth
Introduction
Thank you for the introduction and I welcome the opportunity to speak here today on behalf of CANEGROWERS.
My presentation is called “An ongoing perspective on how industry is balancing the objectives of reef health and growth”.
Being new to CANEGROWERS, I am just getting my feet under the desk and my talk today will discuss my perception and understanding of the current situation around sugar, the Great Barrier Reef and the best management practices being undertaken by the sugarcane growers. Sort of an overview of what I have discovered so far. And I must say, it’s been a fascinating journey and I know I have come in at a very interesting time.
I will focus on three points
1. Perception
· What are the perceptions and how do these perceptions influence decisions
2. Coral bleaching
· What is coral bleaching, what causes it and what can we control
3. From cane cutting to cutting edge
· The evolution of best management practices, the ABCD approach and some examples of cutting edge practices
This all leads to the future and what that means to the sugar industry and the reef.
Perceptions
This picture is by artist Ken Yonitani and is called Sweet Barrier Reef. His work has used sugar to represent coral bleaching. As his website says: “Coral bleaching refers to the process leading to coral death. River waters containing high levels of suspended sediment cause coral death and bleaching. This sediment often comes from harvesting sugarcane, and is known to be one factor leading to bleaching in the Great Barrier Reef.”
In fairness to Ken, he is using sugar as a metaphor for human consumption and its environmental impact. Yet his image reinforces the public perception that seems to come across being that sugarcane is killing the reef. This perception is often reinforced by the media through the reporting of research and opinion. Unfortunately, the science is usually complex and difficult to translate into a newspaper article so we often end up with headlines that misrepresent the facts.
Perception is a powerful thing. And I won’t stand here today and tell you that sugarcane farming doesn’t have an impact, however I feel the magnitude of this impact has been overinflated. We can argue the science, we can discuss the data and we can debate the precautionary principle, but at the end of the day it is the perception that remains.
Coral bleaching
I would like to touch on coral bleaching. As I flew over the Great Barrier Reef near Cairns a few weeks back for a workshop about pesticides on the reef, I thought - there has to be more to it.
As you may know, The Great Barrier Reef is a complex and dynamic system that is in a constant state of change. It is the largest coral reef system in the world and consists of over 2,900 individual reefs and 900 islands. The length of the Great Barrier Reef is 2,600 kilometres and it is approximately 344,400 square kilometres in area. It extends just north of Bundaberg to the northern tip of Queensland. The sheer size and scale of the Great Barrier Reef makes it subject to a number of ecological variables both locally and globally.
The Great Barrier Reef itself can be seen from space. It varies in width of between 60 and 250 kilometres. When people speak about the reef, they talk of it as a whole. However, in the science, monitoring and research context, the reef may consist of the catchment and sub-catchment areas which include the creeks, rivers and estuaries, or it may just be the lagoon, the inner reef, the middle reef and outer reef. So when the stakeholders talk about an impact on the reef – clarification on what part of the reef would be helpful.
The Great Barrier Reef is home to approximately 400 species of coral, many of which form a symbiotic relationship with microscopic algae called zooxanthellae. This relationship provides the coral with up to 90 percent of its energy through photosynthesis. The zooxanthellae also provide the vivid colours in the corals that occur on the reef.
So what is coral bleaching? Coral bleaching occurs when the coral host expels its zooxanthellae due to a stress event within its local environment. Without the zooxanthellae, the tissue of the coral animal appears transparent and reveals its white skeleton. This is coral bleaching. Once this occurs, the coral begins to starve and will often die if the stress continues over a period of time. If conditions in the environment return to normal, corals can restore their zooxanthellae, regain their colour and recover over a period of time.
According to the literature, one of the primary causes of coral bleaching is high water temperature. A temperature increase of only 1.5–2°C lasting for six to eight weeks is enough to trigger coral bleaching and if high temperatures persist for more than eight weeks, coral begin to die.
Another factor causing coral bleaching is freshwater from rain and storm events. The freshwater reduces the salinity of the sea water causing coral stress.
While temperature and freshwater have a significant impact on the Great Barrier Reef, the recent concern is that herbicides, particularly diuron and atrazine, add further pressure.
At this stage the hypothesis is that herbicides along with other agrichemical inputs may contribute to a less resilient reef that would be more susceptible to bleaching events caused by climate change.
In reality, there are a number of factors identified as potential contributors to coral bleaching and these include:
· Changes in water temperatures – either hot or cold
- Changes in salinity from rain and flood events
- Increased solar irradiance - UV strength and amount of sunlight
- Changes in water chemistry – acidification of water from atmospheric CO2
- Starvation caused by a decline in zooplankton levels
- Weather events such as cyclones and storms
- Pathogen infections from bacteria attacking the symbiotic algae
- Increased sedimentation
- Increased nutrient loads
- Agricultural chemicals.
Out of all of these factors, there are three that we can have some level of control over; sediments, nutrients and chemicals. From a management perspective agriculture is easier to manage and regulate than these other factors.
These are the focus of the recent State Government’s Reef Legislation, which sets the target of a 50% improvement in measured water quality at the end of the catchments. The Federal Government’s $200 million Reef Rescue package focuses on these three factors too, however their approach is to incentivise the increased uptake of industry best management practices.
From a sugar industry perspective, the best management practices have been evolving for a number of years, and their uptake has been steady. These practices are based on innovation and supported by science which is designed to drive productivity. This over time has led to the sustainability – environmental, economic and social sustainability.
From cane cutting to cutting edge
The uptake of best management practices is generally influenced by land use and local environmental conditions. You only need to look at the differences between the Wet Tropics and Bundaberg to see this in the sugar industry. Existing practices can be ingrained in tradition and sometimes difficult to change.
Landholders do not always know which practices are best and more often than not, a cursory glance over the neighbour’s fence can be a decision point. The perception is that growers are slow to change, but in reality, adopting better practices is often driven by a combination of available knowledge, the financial capacity and personal motivation of the grower. This is often influenced by the grower’s personal networks (looking over the fence, being a member of CANEGROWERS) and their participating in getting new knowledge and skills.
Looking at the slide, to know where we are going, you have to know where you have come from and I will briefly take you through my understanding of how sugarcane production has moved from cane cutting to cutting edge.
Early cane farming
Late 1800s early 1900s - Manual labour, hand cutting, horses pulling ploughs, carts and various farm implements.
The traditional farming system – 1960s
• Plant crop and two ratoons, and the crop was burnt prior to harvest
• 25% of farm fallowed and generally had poorly managed cover crops
• Three 67-kW tractors and one 50-kW tractors using a variety of implements
• 2.5 onfarm workers
• System:
§ Many in-field operations and tillage practices
- Relatively low nutrient inputs
- Weed control reliant on extensive cultivation
Past farming systems 1980s
- Plant crop and three ratoons, burnt prior to harvest
- Plough-out/replant strategy, limited bare fallow
- Tractor number reduced but size increased - One 82-kW & one 67-kW tractors, variety of implements
- 1.8 onfarm workers
- System aimed at a sugarcane monoculture:
- Land preparation: Multiple passes with ripper/rotary hoe
- Increased use of nutrients
- Increased irrigation
- Combination of cultivation and chemical control of weeds
Improved farming system 2000s
• Plant crop and four ratoons, cut green with green trash retention
• 28% of the farm under break cropping with legumes
• One 93-kW tractor, fewer implements
• 1 onfarm worker
• System:
§ Fewer/less aggressive in-field operations
§ Rationalised nutrient inputs aimed at sustainability
§ Efficient irrigation practices
§ Mainly chemical control of weeds
§ Well-managed and harvested legumes used as break crops and income
As you can see, the past 40 years have seen significant changes in the way farmers grow cane and these changes have had profitability, social and environmental benefits. The fact is growers have had to move to more efficient farming practices to remain profitable, and this has ultimately led to environmental benefits including:
• Rationalisation of fertiliser use
• ‘Softer’, more targeted insecticides
• Less fuel usage
• Optimisation of water use
• Reduced tillage and incorporation of biomass
The ABCD approach
The change in management practices has lead to the ABCD approach. This approach is designed to provide a consistent and comparable sugar land management practice framework to the sugar growing regions. The ABCD principle is applied to soil, nutrient and pesticide management and varies to suit the regional conditions.
A – Cutting edge practices using innovative technology. When these A practices are calibrated they are likely to become a well known acceptable practice for the long term.
B – Currently promoted practices using common technology and often referred to as best management practices. These are acceptable practices for the medium term.
C – Common practices using basic technology and often referred to as code of practice. These are acceptable practices for today but may not be acceptable in the medium term.
D – Practices that are superseded or unacceptable by industry and community standards.
The ABCD approach and subsequent management practices have been developed by growers, NRM bodies and extension groups such as BSES for each region.
The ABCD framework will be used in Reef Rescue to show practice change. With the ABCD framework, growers do not get classed as an A or a B grower. They are considered a grower who uses A or B practices. CANEGROWERS encourages their members to use B practices.
Best management practices
One of the strengths of the sugar industry that I have noticed is that it has a strong science component incorporating research, development and extension. This has, and will continue to, underpin the viability of the sugarcane industry, leading to sustainability and ultimately reef health.
The current best management practices are listed and I will highlight a couple
Green cane harvesting and trash blanketing
This is where the stubble is retained from one year to the next, and the crop is worked including harvest without burning the trash.
Benefits include:
· Increased soil moisture and reduced potential for soil erosion
· Reduced off-site leakage/loss of nutrients and pesticides
· Increased beneficial soil micro-organisms leading to improved structure.
Precision agriculture
This is matching crop agronomy to the production potential of different parts of the paddock or farm.
Benefits include:
· Allows tailored application of inputs such as fertiliser/herbicide through the use of mapping, soil tests, variable rate technology and hooded sprayers.
Reduced/minimum tillage systems with controlled traffic and GPS guidance systems
The soil remains relatively untouched during the preparation and growing season by less working of the field. This includes separating where the cane is grown from vehicle traffic in the paddock by matching wheel and row spacing, guided harvester and haulout tracking, reducing the impact of compaction to the same small area.
Benefits include:
· Improved soil health
· Reduced soil compaction leading to less potential for run-off
· Improved fertiliser management.
Rotation cropping and legume break cropping
The planting of fallow land, about 15% of a farm area on an annual basis with nitrogen fixing legumes such as soybeans, peanuts or chickpeas.
Benefits include:
· Improved soil structure and moisture holding capacity
· Return of nitrogen to the soil and reduced fertiliser requirements
· Improved profitability through reduced inputs, improved soil structure and sale of legume crop.
The future
As we move into the future, a range of pressures, demands and opportunities will confront the industry based around the demand for food, fibre, fuel and pharmaceuticals.
The global need for food will create an additional demand for sugar.
Electricity and fuel demands will provide opportunities for the production of more biomass for steam generation and ethanol. Pharmaceuticals and other valuable biotech products will be produced from the waste stream of sugar and cane production.
These demands will be expected to be met with fewer inputs, less land and with increased environmental scrutiny and regulation. How will the sugar industry balance growth and reef health – through the continued use of best management practices?
One thing I have discovered is that the Great Barrier Reef is subject to a number of factors outside of our control. Farmers and Great Barrier Reef have a commonality – they can’t control the weather.
Reef rescue will certainly provide a catalyst for increased best management practice adoption, a positive initiative. The reef legislation and its proposed regulatory framework will enforce compliance. Hopefully the outcome of these two initiatives, the practice change, the monitoring data and the science will help change the perception – time will tell.
In the end, it will be the sugar industry that will continue to adopt better onfarm management practices that optimise production while reducing the environmental risk.
The new farming system will encompassing a suite of different practices including legume break cropping, controlled traffic and minimum tillage with programs aimed at sustainable nutrient management. These activities together with new technology, science and passion suggest a bright future for the reef and the sugar industry.