How Solutions Become Problems
The focus of this forum piece by KIS Collaborator Darwin Anderson is the application to prairie agriculture of an ecological theory put forward by C.S. (Buzz) Holling. Holling is a well-known ecologist, first with Forestry Canada, then at UBC, later at the U. of Florida, and now retired, still thinking and writing from a coastal community in Florida (Holling, 2006).
Holling's idea on ecological or environmental problem(s) is that as a resource-use problem is recognized, a solution is developed and implemented. The solution often works very well at first, but soon problems related to the application of the solution itself are apparent. The ecosystem(s) or land changes as well, often becoming less diverse and, consequently, less resilient. The solution becomes the new problem.
Anderson applies Holling's work to the adoption of summer fallow (SF) and how that ecological solution eventually became a problem that was solved by conservation tillage. Anderson then raises the question: Is conversation tillage following the same path as SF and becoming a problem that needs a new solution?
Variations to the solution are brought in to partly remedy the 'new' problems, but the initial solution continues, often longer than it should, and because of the prestige given to its proponent(s). One of the examples discussed by Holling (1986) is the spraying of insecticide in New Brunswick's forests to control spruce budworm. The spraying worked well to reduce budworm populations, but actually sustained the populations at moderate levels as the volume of foliage increased over large, protected (sprayed) areas. Not spraying then resulted in an outbreak that could spread quickly over vast areas. The forest industry, the 'spraying' industry and local communities became ever more dependent on continued use of insecticides. Interestingly, in developing models to simulate the impacts of the insecticides on the forest ecosystem, initial versions did not result in realistic predictions (Holling, 2006). It turned out that the missing piece or variable was predation of budworms by the 35 species of insectivorous birds that lived in the forest. Bird predation is effective when budworm populations are low in young forests, but is much less effective with higher budworm populations in older forests with more foliage.
The widespread adoption of summer fallow (SF) as a solution to the problem of unreliable moisture supply to crops in semi-arid regions such as the Canadian Prairies well-illustrates Holling's ideas. With SF, land is not cropped every second or third year, in order to store supplies of moisture in the soil, and thus augment the precipitation of the crop year. Additional benefits of SF are increased supplies of plant-available nutrients due to mineralization of organic matter during the SF year, and better weed control. SF worked reasonably well at first, especially on soils rich in organic matter with higher clay contents and, therefore, greater moisture storage capacity. But problems were soon evident. Problems included soil erosion, waste of nutrients by leaching loss, decline in soil organic matter, increased soil salinity in some situations, and inefficient use of land. These 'solution-related' problems led to adaptations, such as stubble mulch tillage, strip-cropping and shelterbelts to control erosion, increased need for fertilizer as nutrient supplies were depleted, and some use of herbicides rather than tillage. The adaptations allowed the solution to be practised long past its period of effectiveness.
Holling (1986) points out that the management goal is often to reduce the variability of a target variable (soil moisture supply) by applying external controls (eliminating vegetation during the SF year). The solution often is based on an equilibrium-centred view of constant nature. Interestingly, SF is most effective under average rainfall. During droughts, particularly long droughts, even SF does not augment moisture adequately and yields are low. When rainfall is well above average, SF is not really needed. Farmers continued to practise SF because of the difficulty of predicting wet years, and because their farming operations were designed to seed only one-half their land each year.
Many agronomists recognized that SF was not a long-term solution to the problem, predicting the negative outcomes listed above (Janzen, 2001). SF was recommended largely because other options of the time did not work. In the 1970s, Professor Don Rennie of the University of Saskatchewan described SF as one of the most harmful practices ever introduced into farming in Saskatchewan. He was strongly criticized in the farm press, and even investigated by the Saskatchewan Institute of Agrologists for his unpopular and supposedly unscientific views. Eventually, as the evidence built over the decades, SF as the solution to the soil moisture supply problem has been abandoned in favour of another, new and bold alternative.
The new solution for the Prairies is conservation tillage. Conservation tillage or zero tillage describes a cropping system based on the substitution of herbicides for tillage wherever possible. Other components include direct seeding with seeds drilled into soil not otherwise disturbed, often with fertilizer applied in the same operation. The main result is that soil is protected by crop residues, substantially decreasing erosion risk (Huffman et al., 2005). Additional benefits (a win-win situation) include conservation of soil moisture and increases in soil organic matter, or carbon sequestration. Better moisture conservation results in higher yields and allows for continuous cropping in the Black and Dark Brown soil zones, and the more moist parts of the Brown soil zone. Carbon sequestration is part of Canada's strategy to meet Kyoto targets, and may well result in payments to farmers who sequester carbon.
Holling's analysis of similar resource problems is that 20 to 30 years are needed for change; this is the time needed for a new generation of experts and policy advisors to take over. Despite the impression that the ongoing change to conservation tillage happened quickly, it is important to recall the research started at least three decades ago by scientists such as Dr. Wayne Lindwall at Lethbridge AAFC, and farmers such as John Bennett and Jim Halford in Saskatchewan. Adoption of conservation tillage in the 1990s depended on that initial research, and was helped considerably by cheaper glyphosate (Round-up), better machinery, and heightened awareness of the need for better conservation.
Conservation tillage is working well, but there are problems that farmers have to deal with. Some of the problems are persistent perennial weeds, stratification of nutrients and more acidic conditions near the soil surface, the need for specialized equipment and, perhaps in future, herbicide resistance. Glyphosate is the magic bullet, and many weed scientists consider that herbicide resistance is inevitable. Another, seemingly unintended consequence (a surprise) is that farmers are able to farm even more land, especially with the new machines that are bigger, better and faster. This may not be a bad thing for the farmers, but is definitely a problem for rural areas, already disadvantaged because of having fewer people.
Will conservation tillage follow the same pattern as SF, developing problems that require variations to the initial solution, and remaining in place beyond its period of effectiveness? What are possible strategies to supercede conservation tillage? One possibility, being developed mainly by Dr. Wes Jackson at the Land Institute in Kansas is known as perennial polyculture or natural systems agriculture (Jackson, 2002). This strategy closely mimics the prairie with a cover of perennial, seed-producing grasses and forbs that can be harvested once or more each year for food. Research at the University of Manitoba is considering the potential of perennial polyculture, as described on the web site: http://www.umanitoba.ca/outreach/naturalagriculture/.
Holling (2001) describes sustainability as the capacity to create, test and maintain adaptive capability. Certainly, forward-looking research on better ways to grow food in the uncertain environment of the Canadian Prairies needs research of that kind.
This blog entry was authored by Darwin Anderson, a professor in the Department of Soil Science at the U of S. To read additional Illative Blog entries or to leave comments on this entry, please visit www.illativeblog.ca. The Illative Blog is an initiative by the Knowledge Impact in Society (KIS) Project based out of the University of Saskatchewan. Email correspondence can be sent to kis.project@usask.ca
References:
Holling, C.S. 1986. The resilience of terrestrial ecosystems: local surprise and global change. In: WC Clark and RE Munn, editors. Sustainable Development of the Biosphere. Cambridge University Press, Chapter 10, 292-317.
Holling, C.S. 2001. Understanding the complexity of economic, ecological and social systems. Ecosystems 4:390-405.
Holling, C.S. 2006. A Journey of Discovery. Available from http://www.resalliance.org/1.php.
Huffman, E., D. Coote, J.Y. Yang, and F. Chen. 2005. Soil Cover. Chapter 8 (pp 61-68) in A. Lefebvre, W. Eilers and B. Chunn (eds), Environmental Sustainability of Canadian Agriculture, Agri-Environmental Indicator Report Series, Report 2. Agriculture and Agri-Food Canada, Ottawa. Available online: http://www.agr.gc.ca/env/naharp-pnarsa/index_e.php
Jackson, Wes. 2002. Natural systems agriculture: a truly radical alternative. Agriculture, Ecosystems and Environment 88:111-117.
Janzen, H.H. 2001. Soil science on the Canadian prairies-Peering into the future from a century ago. Can. J. Soil Sci. 81: 489-503.
Great article. FYI, the link to the University of Manitoba website does not work. Perhaps it's my computer. (Update: Link has been fixed - thx KL)
The solutions to the problems we face, in any sector over time, are often not very obvious. However, in the spirit of innovation and continuous improvement, we do the best we can with the knowledge and experience available. Darwin Anderson is likely very correct in wondering if the solutions of today will be the problems of tomorrow. There is a cause and effect to everything we do. Moving forward with the best information and intentions is always the best because the alternative, doing nothing, is worse. This is both the challenge and the dilemma of bold leadership.