Conservation agriculture (CA) aims to make better use of agricultural resources through the integrated management of available soil, water and biological resources, combined with limited external inputs. It contributes to environmental conservation and to sustainable agricultural production by maintaining a permanent or semi-permanent organic soil cover. Zero or minimum tillage, direct seeding and a varied crop rotation are important elements of CA.
Adoption of CA at the farm level is associated with lower labour and farm-power inputs, more stable yields and improved soil nutrient exchange capacity. Crop production profitability under CA tends to increase over time relative to conventional agriculture. Other benefits attributed to CA at the watershed level relate to more regular surface hydrology and reduced sediment loads in surface water. At the global level, CA sequesters carbon, thereby decreasing CO2 in the atmosphere and helping to dampen climate change. It also conserves soil and terrestrial biodiversity.
Conservation agriculture is practised on about 57 million ha, or on about 3 percent of the 1 500 million ha of arable land worldwide. Most of the land under CA is in North and South America. It is rapidly expanding on small and large farms in South America, where practising farmers are highly organized in local, regional and national farmers' organizations. In Europe, the European Conservation Agricultural Federation, a regional lobby group, unites national CA associations in the United Kingdom, France, Germany, Italy, Portugal and Spain.
Despite these apparent advantages, and despite the few notable exceptions in the developing world, CA has spread relatively slowly, especially in farming systems in temperate climates. The transformation from conventional agriculture to CA seems to require considerable farmer management skills and involves investment in new equipment. However, it may also require minimum levels of social capital to foster its expansion.
In the light of this situation, the aim of this study is to identify and analyse the financial and other conditions that spur farmers to adopt CA practices. The study reviews the literature and analyses the economics of technology adoption at farm level. It identifies divergences between privately appropriable benefits and national or global economic benefits stemming from an expansion of the area under CA. It also examines the policies and options for bridging these, particularly in the light of the current policy setting in both developed and developing countries.
The remainder of this chapter examines the concept of CA. It discusses the economic benefits of CA in order to develop a rationale for intervention at the national and international levels to promote CA adoption. It then presents a conceptual framework to help understand the influences that correlate with the adoption of CA by farmers. Chapter 2 analyses the farm-level situation in terms of financial incentives for adoption and other factors. Chapter 3 discusses the existing policy setting for CA and highlights new directions for policy. Chapter 4 presents conclusions and recommendations from the study. The appendixes provide summaries of other studies examined in the course of the research.
CA has emerged as an alternative to conventional agriculture as a result of losses in soil productivity due to soil degradation (e.g. erosion and compaction). CA aims to reduce soil degradation through several practices that minimize the alteration of soil composition and structure and any effects upon natural biodiversity. In general, CA includes any practice that reduces, changes or eliminates soil tillage and avoids the burning of residue in order to maintain adequate surface cover throughout the year (ECAF, 2001). In contrast, conventional forms of agriculture regularly use ploughs to enable a deep tilling of the soil (FAO, 2001). The line between conventional and CA often blurs as conventional agriculture utilizes many practices typical of CA, such as minimum or no-tillage. Hence, the differentiating feature of CA and conventional agriculture is the mind-set of the farmer. The conventional farmer believes that tilling the soil will provide benefits to the farm and would increase tillage if economically possible. On the other hand, the conservation farmer questions the necessity of tillage in the first place and feels uncomfortable when tillage occurs.
CA maintains a permanent or semi-permanent organic soil cover consisting of a growing crop or a dead mulch. The function of the organic cover is to physically protect the soil from sun, rain and wind and to feed soil biota. Eventually, the soil micro-organisms and soil fauna will take over the tillage function and soil nutrient balancing, thereby maintaining the soil's capacity for self-recuperation. Residue-based zero tillage with direct seeding is perhaps the best example of CA, since it avoids the disturbance caused by mechanical tillage. A varied crop rotation is also important to avoid disease and pest problems. The last two decades have seen the perfecting of the technologies associated with minimum or no-tillage agriculture and their adaptation for nearly all farm sizes, soil and crop types and climate zones.
Some examples of CA techniques include:
The definition of CA used in this study is broader than that used by FAO (no-tillage with direct seeding and maintenance of soil cover/crop residues with no incorporation, along with crop rotations). The wider interpretation of the concept encompasses a larger number of data and informational sources, as many studies employ differing definitions of CA and the broad definition presented here captures most of this variation.
Table 1 presents a profile of benefits and costs associated with CA. The distinction between local, national and global impacts is important as it is possible to rationalize national or global programmes supporting the adoption of CA according to how significant the net benefits are at this level. The benefits at the national level are especially important and they strongly argue for policy support at this level. Uri et al. (1999a) estimated that the realized erosion benefits (avoided losses from sheet, rill and wind erosion) for the United States from the existing areas under conservation tillage ranged from US$90.3 million to US$288.8 million in 1996.
From the farmer's perspective, the benefits of CA can be either on-site (private) or off-site (reduced sediment pollution, carbon sequestration, etc.). Table 1 shows that while many of the incremental costs associated with adopting CA accrue at the farmer level, relatively few of the benefits do so. Table 1 appears to confirm that there is a divergence between the social desirability of CA and its potential on-farm attractiveness.
Few empirical studies consider the economic benefits of adopting CA in the tropical agro-ecological zone, so most accumulated evidence is for developed regions such as North America. For example, Stonehouse (1997) simulated full-width no-plough and no-till use in southern Ontario, Canada, and found that both provided modestly higher on-farm benefits than did conventional tillage. The advantage of no-plough and no-till was even greater with off-site benefits included. The off-site benefits considered were downstream fishing benefits and reduced dredging costs. These accounted for 43 percent and 10 percent, respectively, of the net social benefits from conservation tillage. Thus, despite marginally higher profits under CA, the inability to capture off-site benefits means that fewer farmers adopt CA than might otherwise be the case.
Other studies find a trade-off between economic returns and environmental integrity with the adoption of increasingly intensive conservation agricultural practices. Kelly et al. (1996) find that strict no-till produces higher returns than conventional tillage and reduces an environmental hazard index from 78.9 to 64.7. The index takes into consideration soil erosion risk, phosphorous and nitrogen losses, and potential pesticide contamination. By further incorporating cover crops and replacing fertilizers with manure, the CA option becomes less profitable than conventional tillage. However, the environmental hazard index declines to 50 or lower, making the economic-environmental trade-off clear from a social perspective.
The global concern about soil degradation helps support an argument for intervention at the international level. This argument stems not just from a concern about what is occurring within individual nations but also from the possible presence of regional or global costs imposed by soil degradation. In other words, there may be global benefits from adopting CA and other soil-enhancing technologies. Table 2 presents a classification of the various ecosystem functions associated with soil resources that might have a global dimension.
Table 2 shows that there are potential global benefits associated with the adoption of CA. For example, there is a link between carbon sequestration in soil and global warming as the long-term capture of carbon in organic matter reduces the atmospheric load of carbon. However, the benefits associated with carbon sequestration in soil may be elusive if soil degradation results in a transfer of carbon from one location to another with no net release to the atmosphere. For CA, Uri (1999a) argues that the "benefits to be gained from carbon sequestration will depend on the soil remaining undisturbed".
In the absence of sustainable soil management practices, soil degradation can lead to crop and livestock losses, with regional or global consequences (refugees, famine, etc.). Where the rest of the world provides assistance, these resources are wasted if the earlier adoption of CA or other practices could have avoided the situation. In addition, lands under CA support terrestrial wildlife and soil microfauna that are important components in global biodiversity, as demonstrated by the discovery of penicillin and streptomycin. Thus, good soil conservation and management can have benefits that the individual farmer does not anticipate, but which do have real implications for the global environment.
Farmers who switch to some new technique from conventional practice may do so for a variety of reasons. They may detect a more efficient and profitable way to produce, or they may perceive a problem and in seeking solutions arrive at a new practice, such as CA. The problems stimulating the possible change to CA are typically soil degradation, soil erosion or declining crop yields due to deteriorating soil fertility. These views are associated with the traditional model of innovation and the adoption of new technologies in many industries, including agriculture (Box 1).
Some farmers have adopted CA because they found that immediate yield benefits or profits were attractive. In this situation, a clear financial incentive has induced the change in behaviour, as suggested by the classical model described in Box 1. However, it may be inappropriate to rely on the classical model as a basis for promoting the adoption of agricultural conservation technologies (e.g. no-till). This is because the adoption and diffusion model is based on "voluntarism on the part of the farmer's decision making and the economic gain attached to the new behaviour" (van Es, 1983). As conservation technologies may result in net social benefits, but may also result in a financial loss at the farm level, the classical model shown in Box 1 may not bring about a socially optimal level of CA adoption.
The study of innovation adoption and diffusion has its origins in the Midwestern United States. In an Iowa State University study, Ryan and Gross (1943) showed that the pattern of adoption and diffusion of a maize hybrid was systematic (i.e. regular), thereby opening the door for further research. The adoption and diffusion of the innovation process has been characterized as the acceptance over time of some specific item by individuals (or adopting units) linked to specific channels of communication. The `innovation' includes "any thought, behaviour, or thing that is new because it is qualitatively different from existing forms" (Jones, 1967). This wide definition captures any idea or process that is perceived to have utility. In an agricultural context, this might be a new crop variety or management practice adopted by an individual, family or corporation. Much research has focused on the adopter in order to determine what variables might contribute to the adoption or rejection of an innovation. While profit/satisfaction maximization is commonly a key determinant, other variables such as education levels of adopters can play a significant role in adoption. Finally, `diffusion' is the process by which an innovation spreads over time within a given social system. Figure 1 shows the bell-shaped distribution of individual innovativeness and the percentage of potential adapters typically thought to fall into each category. On one extreme of the distribution are the innovators. Innovators are the risk takers and pioneers who adopt an innovation very early in the diffusion process. On the other extreme are the laggards who resist adopting an innovation until rather late in the diffusion process, if ever. Figure 2 plots adoption over time. Typically, innovations diffuse over time in a pattern that resembles an s-shaped curve. That is, the adoption rate of an innovation goes through a period of slow, gradual growth before experiencing a period of relatively dramatic and rapid growth.
Source: Surrey, 1997.
Moreover, some authors argue for the presence of a continuous complex innovation process governing agricultural technologies such as CA, using the example of zero tillage. These innovation systems are non-linear and involve complex interactions and feedbacks among agents (e.g. farmers, extension agents, and private enterprises). These authors argue that continuous complex innovation systems are characterized by the presence of agents that have limited information but are always in search of new technological opportunities. In addition to individual agents' actions, initial circumstances and the working of feedback loops have a great bearing on the innovation process, making it unpredictable. The resulting technological innovation stems from a particular mix of initial conditions, random events and long-term trends. As an example, the response of pests to new control techniques is unpredictable, yet has a significant influence on the evolution of future technology development and adoption.
Regardless of the motivating factor or the model of adoption assumed, farmers consider only those aspects of their operation that are relevant from a private perspective. This process typically involves only on-farm considerations. However, it could extend to impacts on neighbours and future generations if social relations and stewardship considerations receive high personal priority. Despite the more limited view, many factors influence this private perspective and help to mould decisions about new technologies or a change in farm practices. Figure 1 shows one view of this process.
In Figure 1, households make technology choices and decisions about the use of their soil resources under the constraints imposed by their socio-economic attributes and on-farm resources, as well as higher level factors at the local to global scales. For example, lacking adequate tenure and access to credit, the farmer cannot invest in CA if this requires a large capital outlay. Information about new technologies and financial conditions is a precursor to changes in farm practices and acquiring it does not usually involve large financial outlays. Government credit and extension policies play an important role here. In contrast to the more direct working of agriculture sector policies and financial incentives, some social and institutional factors have a more indirect influence. Nonetheless, all these factors affect the net returns, risks and other pecuniary elements that drive the decision-making process.
Central to this model of the decision-making process are farmers' perceptions. Changing policy and financial incentives or declining natural resource quality signal to the farmer that the current pattern of use of household resources may no longer be desirable. There is controversy over the extent to which farmers perceive progressive deterioration in their natural resource base. However, there is now sufficient evidence that smallholders are often aware of soil degradation, although other factors affecting production may mask this at times. Figure 3 portrays the detection of soil degradation as the working of feedback mechanisms.
CA is just one of many options available to farmers responding to perceived changes in their production environment. For example, all or a few of the household's members may migrate or accept off-farm employment, or remain behind and modify farming practices. Critically, the impact on soil productivity can be either positive or negative, depending upon numerous factors. If households choose migration, they may reduce the intensity with which they farm existing plots, or abandon their old lands altogether and bring new land in frontier areas under cultivation. The latter can have serious implications if farmers transfer unsustainable soil management practices to new areas. There are also many technical alternatives available to producers if they choose to change existing management rather than migrate, and these include CA. The choices of individual farmers are cumulative and can have eventual impacts well beyond the individual farm (Table 2).
The working of the feedback mechanisms (Figure 3) closes the loop and there is the potential for either a self-reinforcing series of improvements in soil productivity, or spiralling degradation.
Source: adapted from Bradshaw and Smit, 1997; and FAO, 2001.