One of the famous sights in Venice is the baroque church of Santa Maria on the outer Grand Canal. The building of this church began with the driving of more than one million trunks of trees into the mud of the lagoon on which Venice is built. Once the trunks were submerged, they were no longer exposed to the air, and the wood was protected from decay and remains as the foundation for the church. Most of Venice is built on similar wooden foundations.

Venice is probably the most beautiful city in the world - it has given immense pleasure to its citizens and tourists for hundreds of years. The analogy of Venice raises some interesting questions. Could the city of Venice be constructed on a wetland today without a great deal of fuss and many environmental impact statements? Would a community today countenance the cutting down of a million trees to provide the foundations of just one building? These are questions I do not want to pursue here. But with respect to the environment of our country, we are in a position similar to that of the ancient builders of Venice confronted with the marshes of the Adriatic Sea. We are confronted with problems and the solutions are often unclear. We face a continuing challenge of adapting to a difficult natural environment and, within reason, adapting an environment to the demands of our agriculture.

In the past decade there has been increasing concern about the sustainability of our land use. One can be pessimistic or constructive about these things. Today, in the quest for a sustainable agriculture we are not empty-handed. In Australia we are the beneficiaries of a rich history in the development of science and ideas about land use and about conservation. Our current community stock of knowledge of how to farm is the result of a long process of evolution by trial and error and learning by mistakes.

The history of Australian rural land use is the story of a continuous 200 year experiment. From the failure of the first convict-sown wheat crop, through to the present time, Australians have sought to develop a sustainable agriculture. Sometimes this experiment has achieved spectacularly successful results. Sometimes it has created unforeseen ecological problems.

Maintaining the research initiative: The example of wheat

The history of fallow in Australian wheat cropping is a good example of the dynamic nature of the search for a sustainable system of agriculture. The history of changing practices of wheat growing demonstrates the parallels between crop yields, the environmental state of cropping soils and the continuing development of knowledge to overcome changing problems.

Early in this century the excessive use of the formerly 'scientifically approved' practice of bare fallowing on weakly structured soils led to a serious loss of soil and damage to soil structure. For 30 years from 1925, soil erosion posed a real threat to the stability of a considerable amount of Australia's cropping and grazing land. The introduction of superphosphate helped overcome soil nutrient exhaustion. By the 1920s all wheat farmers in southern Australia were manuring their crops and most were sowing with superphosphate. By the 1930s improved pasture species, legume nitrogen, better rotations and changes in management practices were being introduced and, with scientific discoveries allowing the control of rabbits, the worst erosion in Australia's history was overcome by the 1950s. The period of high wool prices after the Second World War encouraged the adoption of new legumes and rotational cropping practices which did much to overcome the worst soil erosion and fertility mining of previous decades.

The problems associated with dry fallow were caused by ill-informed enthusiasm, excessive use, and the farming of marginal lands. In the early years of dry fallow there were few generally known practical or economic methods of enhancing soil fertility. The continued practice today of less vigorous fallowing and mechanical cultivation has produced other problems of soil structure only more recently noticed. On many soils excessive cultivation - which, as a component of bare fallowing, once made organic nitrogen available to wheat crops - has now reduced soil organic matter and created a soil structure less amenable to sustainable cropping. New minimum tillage and zero tillage practices have been developed to overcome this problem. The substitution of herbicide chemicals for mechanical cultivation has provided the current solution to this problem. Future concerns about chemical residues and herbicide resistance may well make this solution unsustainable in the future.

One of the solutions to the earlier problem of bare fallowing, the use of legumes to provide soil nitrogen, has now itself presented a new problem in some parts of southern Australia - soil acidity brought about by a build-up of soil nitrogen in a form which acidifies the soil. The current technical solutions to soil acidification are not economic within the long-term terms of trade for broad-scale wheat production.

New technological solutions will be required. The lesson is that there is never likely to be a single management system for cropping that endures forever. We have to keep inventing new systems. As well, we have to face the ecological reality that too much of anything is a bad thing in a living system.
We are unlikely ever to know enough to completely manipulate the ecosystems and social systems which comprise commercial agriculture to produce a system which we know, in advance, will be ecologically and socially sustainable. We should keep in mind that Australia's agricultural systems incorporate both natural resources and human resources, including the production of new technologies and management skills.

The growth of landcare

Landcare groups have been a growth industry in environmental conservation. The formation of landcare groups has outstripped the technical and support resources available to service them. In announcing the 'Decade of Landcare' the Federal Government hoped there would be 1200 groups by the year 2000 (Hawke, 1989). The target has already been exceeded. Landcare groups have been forming in Australia at an exponential rate. The number of groups has increased from about 100 in 1985 to 900 groups in 1991 and 1400 groups in 1992 (Figure 1). In Victoria, a quarter of the State's farmers are members of landcare groups. The enthusiastic embrace of landholders for the landcare movement is a phenomenon that has no current equivalent in other western countries.

Figure 1: The growth of landcare groups in Australia

In its early development, landcare was closely associated with planting trees. Since the development of landcare, farmers have been planting many more trees, but often this appears to have been motivated by aesthetic reasons rather than ameliorating land degradation. This focus on tree planting has sustained the movement socially and politically. The lack of reliable information about causes and likely outcomes of many of the problems related to sustainable land use has meant that symbolic and simplified policies often have run ahead of real understanding (Cary, 1993). Tree planting has provided a relatively cheap and technically simple focus around which landcare groups could develop. The results of tree planting programs are tangible and obvious, even if the land degradation implications are elusive and somewhere in the distant future.

Challenges for a maturing landcare

The tree has long been a potent symbol. The cedar on the Lebanese flag and the rainforest tree symbolising threats to forest ecosystems are just two examples. The tree planting focus has provided a potent political symbol which can be appreciated by urban electorates. Politicians have not been slow to recognise this. As part of the 'Decade of Landcare' the Federal Government proposed a community program for planting 400 million trees in its one billion tree planting program. The image of the politician planting a tree to symbolise the commencement of a new landcare initiative has become common place on our television screens. It is much more difficult to provide the same symbols for most new sustainable farming practices.

The agricultural industries which use Australia's land and water resources are generally extensive in their use of land resources, high in output per unit of labour and a large proportion of output is sold in competitive export markets. Government payments and subsidies to most agricultural industries are low or insignificant. Opportunities for governments to influence adoption of conservation practices using cross-compliance programs linked to government payments to agriculture are minimal. In the past, unlike in the United States, there has been little cause for the majority of urban voters to seek implementation of legislative controls on rural land use practices which cause land to degrade. Most Australian soil conservation programs rely predominantly on voluntary compliance or the informed self-interest of land users. Public interest and support for these programs has ebbed and flowed in cycles triggered by major droughts and city dust storms in the urbanised south-east corner of Australia. The spectacular drought of the 1940s and the events of 1982 both sent large dusts clouds over Melbourne and both were followed by government and public concern over land degradation.

The initial rationale for many landcare groups often was to engender awareness of problems of land degradation and the possible solutions to such problems. As the groups have matured they have tended to move from tree planting schemes to focus on implementing practical methods of farming which incorporate improved systems of land management. The influx of members to the movement has diluted the initial greener idealism with a touch of brown pragmatism. In one of our studies we found early members of landcare were more disposed to plant trees in sufficient numbers to potentially reduce land degradation. More recent landcare members were more likely to plant token numbers of trees in terms of influencing land degradation (Wilkinson and Cary, 1992). Farmers who have planted trees for shelter or for aesthetic purposes are unlikely to be planting trees in the areas where they might influence land degradation.

This browning of the landcare movement can be seen in the changing names and locations of landcare groups. In Victoria the first formed groups generally named themselves either landcare groups or farm tree groups. These groups were generally in the hilly grazing country of the Great Divide where tree planting was a practice generally compatible with local grazing property management practices. There were very few landcare groups in cropping, horticultural and irrigation districts. Today the generic concept of landcare encompasses groups with names like Soilcare or Farm Advance. The focus of these newer groups is on both productivity and conservation (Wilkinson and Cary, 1993).

As landcare has matured as an 'environmental' movement the idea of trees as a panacea to remedy all land degradation problems has waned. Pragmatic self-interest suggests that turning farms into forests is likely to be viable only for those for whom farming is a hobby or perhaps for those with high taxable incomes. This is not a problem shared by many modern full-time farmers. Farmers' responses to their environment depend on the ecological constraints imposed by their environment but, probably more importantly, their responses are coloured by the society in which they find themselves. Farmers are not insensitive to community attitudes to environmental issues. The maturing of landcare reflects a working through and reappraisal of the naive ideal with what might be more pragmatically feasible for the longer term. For those farmers facing low commodity prices, it is hard to be green when 'in the red'. The more realistic landcare proponents recognise the need for farms to be financially viable and productive to provide the necessary basis for investments of a 'green' nature to tackle the more intractable forms of land degradation.

The most effective landcare practices will be those which combine caring for the land with improving productivity. The recognition of this necessary complementarity is a natural evolution if the landcare movement is to be sustainable and to operate without large government subsidies.

Challenges of changed community understandings

In two hundred years since European settlement, Australia's land has changed. From the point of view of modern agricultural use, while some land is seriously degraded, other land is in a more productive state than in times past. When humans dwell on land it will always be changed. There can be little serious contention that the net change has been for the better. What is at issue is the extent of the negative effects and the extent to which they ought to be rectified.

One of the naive views about the environment is that, in an ideal state, the land and its natural flora and fauna do not change. The land and ecosystems in Australia were in a state of change before the Aborigines, during the Aboriginal settlement, and during European settlement (Cary and Barr, 1992). Nature is dynamic rather than constant. The famous American conservationist, Aldo Leopold, said that "conservation is a state of harmony between men and land". Even for nature undisturbed, that harmony is not a monotone.

The proper response to the problems we have created for the environment with our technology is not to abandon civilisation or modern technology, as some argued. Having altered nature with our technology, we must depend on technology - wisely used - to see us through to solutions. In the process, we will learn to live in better harmony with nature. And those harmonies are more complex than they seem.

European man has had a big influence on the land since whites settled Australia. The history of our land is different to the history of Venice; but we have not always changed our land as much as some people think. The belief that there has been a dramatic deforestation of the land which, in turn, is the prime cause of land degradation is too simplistic. So too is the belief that replanting trees is the obvious solution to most degradation problems. The truth is far more complex. In many cases we do not yet know enough to know the answers.

The complexity of land degradation presents a challenge for communicating with the general public. In the debate over the seriousness and importance of environmental issues, there are strong temptations to promote stark assessments of the problems we face and advocate simple solutions, weaving a spell of misplaced confidence. The attractiveness of simple solutions to complex problems is an inevitable outcome of the natural human desire to avoid uncertainty. The trend is further encouraged by the nature of the electronic media. Commonly, the image of land degradation is communicated in stark extremes: a black and white case in full colour. The most pervasive examples of land degradation are less dramatic, more subtle and sometimes hard to recognise. There is a delicate line to be trodden between over-simplification, being realistic about what can be achieved, and confusing the public with the sometimes complex realities.

Challenges For Research

There is a danger in simple belief that the most important task to achieve a more sustainable agriculture is the raising of community awareness and changing of farmers' attitudes to their land. This may be a necessary condition for change to occur. It is most unlikely to be a sufficient condition for change to occur. The history of changing agricultural practices in Australia provides some important lessons in how to encourage the use of more sustainable land use practices now. Historically, the clearest feature of the practices which have been, at some period, of major importance in sustaining agricultural land use in Australia, and which have been widely adopted, is that they offered realisable advantages to farmers. What is required are profitable and practical conservation farming techniques and management strategies. Where these are not available the best assistance is research directed at producing and promoting practical and profitable solutions, rather than too much reliance upon evangelical calls for better farming.

Today there are a number of environmental problems associated with farm land for which, currently, there are no adequate solutions. Sometimes there may be solutions available but they are not appropriate nor adequate for widespread on-farm use. In such cases the problem is not that farmers have the wrong attitude to land stewardship, or that extension is not working but rather, that the current technologies are inadequate. Currently, practical and profitable solutions which can be easily incorporated into farming systems do not exist for problems such as irrigation-induced rising ground water, soil acidification, regionally-induced dryland salinity, woody weeds in the rangelands, vertebrate pests in the rangelands, regional dieback of native remnant vegetation, and nutrient contamination of water courses and wetlands.

National Opportunities Presented By The Australian Environment

Australian farmers often appear to be powerless and disadvantaged in the face of the agricultural trade policies of major nations with developed economies. There are some signs that, with the growing demand for smaller government and an ageing population which requires reallocation of government funds to pensions, tolerance for additional cash handouts to farmers is diminishing in some of the major economies. As well, the increasing use of export subsidies, production quotas and cropland set-asides has weakened the traditional argument of national food security as a justification for further assistance to agriculture. High food prices in economies with protected and subsidised farm sectors have encouraged farmers to use greater volumes of chemical fertilisers and pesticides, animal growth hormones and more irrigation than would otherwise be the case. The consequent adverse effects of intensified input use on food safety and the environment, especially in densely populated countries, is reducing the preparedness of urban people to continue to tolerate agricultural price supports (Anderson, 1992).

The consequences of these forces, and the increasing concern of consumers for 'clean' food, provides potentially great opportunities for Australia. The need to maintain, and improve, Australia's status as a relatively 'clean' agricultural producer with relatively low levels of environmental pollution, and low levels of damage to both the local and global environment, is paramount to grasping such opportunities. There is some concern that overseas farm lobbies will play on the concerns of consumers regarding food safety and of the environmentalists worried that food trade liberalisation will stimulate more felling of tropical rainforests (Anderson, 1992). In bilateral trade arrangements, Australia should be able to capitalise on such perceptions, but may lose out if such perceptions damage relaxation of multi-lateral trade barriers. In the longer run, more informed environmental groups are likely to realise that removal of agricultural protection policies in densely populated countries will see a relocation of food production to the more scarcely populated southern hemisphere and developing countries where use of farm chemicals and damage to the global environment by farmers is far less intense.

Challenges of a dynamic agriculture

The dynamic nature of a sustainable agriculture involves a continuous learning experiment; it implies we do not know all the answers. The history of fallow in cropping and the history of irrigation in Australia shows the mistakes and the changes in thinking that are part and parcel of trial and error learning.

Innovation and development of new knowledge has been an evolutionary process. Many of the current prescriptions for problems of Australia's land use may not stand the test of time and future new knowledge. Landcare has been important, but it will also be important to do the necessary science, just as it has been in the past.

There are some things we can learn from the history of the search for sustainable land use in Australia. The successful solutions to past problems of unsustainable land use had clear characteristics. We need to be looking for the same characteristics today. The solutions need to be commercially profitable, relatively easy to implement, socially acceptable, and environmentally benign. Innovation and development of new knowledge is an evolutionary process. The experiment will never be completed. It is important to keep up the will to want to keep learning. Just as the ancient Venetians had a history of technology and knowledge of how to cut and use wood and stone, so we have a rich history of techniques to allow us to use land wisely and to overcome many of the problems we currently face. We must continue to develop and foster our knowledge and our research base.

References

1. Anderson, K. (1992). International dimensions of the political economy of distortionary price and trade policies. In I. Goldin and L.A. Winters (Eds), Open economies: adjustment and agriculture. Cambridge: Cambridge University Press.

2. Barr, N.F. and Cary, J.W. (1992). Greening a brown land: the Australian search for sustainable land use. Melbourne: Macmillan.

3. Cary, J.W. (1993). The nature of symbolic beliefs and environmental behaviour in a rural setting. Environment and Behaviour, 25:555-576.

4. Cary, J.W. and Barr, N.F. (1992). The semantics of forest cover: how green was Australia? In G. Lawrence, F. Vanclay and B. Furze (Eds), Agriculture, environment and society: contemporary issues for Australia. Melbourne: Macmillan.

5. Hawke, R.J. (1989). Our country our future (Statement on the environment by the Prime Minister of Australia). Canberra: Australian Government Publishing Service.

6. Wilkinson, R.L. and Cary, J.W. (1992). Monitoring landcare in central Victoria. Parkville: School of Agriculture and Forestry, The University of Melbourne.

7. Wilkinson, R.L. and Cary, J.W. (1993). Monitoring soilcare in north east Victoria. Parkville: School of Agriculture and Forestry, The University of Melbourne.