The following represents a synthesis of the scenarios for sustainable cane farming developed by focus groups. It is a composite view of the most desirable sustainable cane farming system for the Mackay region that the participants could envisage in 1993. (Note while each group generated a separate scenario there was a great deal of common view on the themes.)
Farmland: While soil erosion remains a persistent threat, the land resource is managed for soil conservation, soil improvement and vertical expansion. Strategies for minimising erosion include local regulatory control and minimum tillage approaches. Practices that are especially useful are strategic row direction, revegetation, less intensive farming on marginal or sloping lands within a framework of whole farm planning. Soil erosion control relies both on physical conservation structures and attention to soil improvement. By using rotations, green manure crops, trash blankets and alternative fertility management there is significantly less erosive runoff from soil more capable of absorbing rain or irrigation water; Physical erosion control structures such as contouring, optimising row length and slope, improved drainage and improved farm planning further decrease erosion. With increased irrigation use, growers are able to stabilise tilled soil against erosion, ensure early establishment of cane roots and cover crops. A proportion of increased income resulting from improved land management is reinvested in further soil conservation work.
Vertical expansion increases farm income with planning based on the actual capacity of land resources. Practices used to facilitate vertical expansion include irrigation, green trash blankets in moisture deficit areas, new varieties of cane and the retention of best cane lands for farming.
Wider social responsibility is recognised by farm managers through increased revegetation and creation of wildlife habitat. Farmers, however, retain the right to control pest wildlife where their impact is economically significant. Urban/rural communication has improved and there is better understanding of the necessary compromises and achievements. One result is an increased sense of
Farming Operations : In the actual techniques and approaches on the farm, sustainable cane farming focuses on managing organic matter through-put and erosion control for soil health maintenance. To maintain soil structure and long term fertility, fertiliser and organic matter materials are recycled within the farming region both on-farm and with mill wastes. While burning of trash is much reduced, it is retained as a useful management tool for some situations. In minimum till areas, more finely chopped trash is incorporated to advantage with lighter tillage equipment and minimum erosion risk. Wherever possible, green harvesting and trash blankets are used. Fallow periods are managed to increase organic matter through-put by eliminating bare fallows, increasing the percentage of cane lands in fallow and running longer fallows for multiple green manure or alternate crop cycles.
Erosion control is seen as a priority with the primary strategy being minimum and zero tillage techniques with and without trash blankets. Increased organic matter through-put, drainage, reduced compaction, and irrigation availability have resulted in improved soil structure and less erosion. Correct farm layout including optimum row length, contour tillage, and drainage works result in greatly reduced erosion. Compaction has been reduced through use of high flotation equipment, minimising ground contact and wet weather harvesting.
Machinery is now designed and engineered specifically for cane. High flotation equipment is a priority. The higher cost of green capable harvesters is accommodated by cooperative or contractor ownership. Increased rates of harvest from automatically controlled base cutter height and reduced green cane losses make green harvesting more economical with efficient operators.
Irrigation efficiency improvements have reduced labour and pumping costs. Compaction or water logging stress is also reduced. Improved safety and application of farm chemicals lead to fewer environmental impacts; alternate crop development is limited unless it fits into existing fallow periods or utilises mill infrastructure.
Fertility Management: There has been a gradual transition from synthetic to biological and mineral fertility management. The focus is now on building biological systems based on organic matter, legumes, and minerals instead of massive single inputs of volatile chemical fertilisers.
Most synthetic, non-renewable fertilisers have already been phased out. For those still is use, the principle of 'use only where applied' is the rule, accomplished by utilising non-mobile and non- volatile forms, more careful application, concentrated forms for ease of transport and by spreading out fertiliser applications to match plant needs through foliar or slow release materials. Biological and mineral fertility management becomes the primary strategy, based on a total system approach that endeavours to improve or maintain soil fertility and structure. Urban, mill and farm wastes are recycled, possibly after composting on-site or processed at the mills/treatment plants. Green trash blankets, adapted legumes, green manure plough downs, ground covers and continuous cover crops contribute nutrients and organic matter to maintain soil self fertilisation through microbial activity.
Biological nitrogen fixation is developed in the cane plant and/or in the rich rhizosphere life zone around the plant's roots using beneficial bacteria, fungi, algae, and mycorrhizal symbionts.
Naturally occurring growth promotants are used to regulate and encourage growth when needed.
Water Management: Total water use for irrigation increases in sustainable cane farming but recognises the need for greater control, increased efficiency, and the essential interdependence of irrigation and drainage. Irrigation and drainage schemes are done on a district wide basis
Keeping It Sweet - ACF
coordinated with urban water supply systems. While there are some larger dams, where possible increases in water storage and supply are local and on-farm.
On-farm, improved drainage in wet times is accomplished by levelling, whole farm planning, underground and surface drainage, and improved soil structure. This water is stored until needed in on-farm dams for recycling of both irrigation tail water and excess rainfall.
Moisture retention in dry times from improvement in soil structure and moisture holding capacity results from active soil life, organic matter through-put, contour tillage, and trash utilisation (both incorporated and trash blanket). Ground water recharge increases from soil moisture retention, water storage, and revegetation of stream banks.
Water pollution off the farm is avoided by full application of the principle of "keep the soil and nutrients on the farm,". Erosion and run-off contamination are managed on-farm so they don't cause problems off-farm. Automatic irrigation based on automatic monitoring reduces irrigation water waste while conscious scheduling of irrigation ensures the correct amount of water is absorbed by the soil. Increased irrigation availability allows quick ratoon regrowth and rotation crop establishment, reducing erosion/run-off risks. Longer fallows to increase fertility and structure tend to reduce total water use. Preference for non-mobile fertilisers and non-residual chemicals becomes clear as farmers realise that what they apply, they keep on the farm and concentrate in the farm dam. Buffer strips along streams and ground covers help slow the movement of water and contaminants, keeping them on the farm. Biological fertilisation and pest control strategies reduce the problem of contamination by chemical agents.
The technology of water use changes with increased monitoring of water need and quality, low pressure booms, trickle techniques and irrigation scheduling. Improved soil moisture retention lead to increases in irrigation efficiency. Stream flows are maintained for aquatic life and dams are possibly used for aquaculture or wildlife/ tourism ventures.
Pest And Disease M a n a g e m e n t : Chemical use in general is much reduced. Residual chemicals are no longer used or are greatly reduced with higher safety to humans and the environment.
Chemicals used are more selective herbicides and target specific pesticides rather than broad spectrum types. Biodegradable forms of chemical pesticides are preferred.
Alternative strategies for pest control use naturally occurring chemicals such as allopathic compounds in cane that discourage weeds, plant responses to pests that attract predators, biological controls, predators, parasites and beneficial microorganisms.
Breeding for disease resistance continues, possibly using genetic engineering techniques and the present disease control quarantine system continues. Plants are bred for pest and disease resistance and possible resistance to specific herbicides. Research and extension is focused on-farm for practical, commercial scale results. Communication between rural & urban communities on pest control material use increases and growers are fully educated on I P M strategy, safety of materials and application, and monitoring of economic damage thresholds, according to local conditions.