Shifting agriculture is the oldest and most straightforward agricultural system in world. An area of native vegetation is cleared, the debris is burned or removed, and crops are planted and harvested until conditions are no longer favorable, at which point the area is abandoned and a new area is cleared. In most situations this shifting is due to an exhaustion of the natural soil fertility, although in some settings weed or pest pressure can be the motivating factor. When there is sufficient land available, the fallow period of abandonment is sufficient for the regeneration of the native ecosystem, typically forest, as well as the soil fertility through the growth and decomposition of the fallow vegetation. In addition to restoring fertility for the next cycle, the fallow vegetation provides a wide assortment of food and fiber products and can disrupt the life cycles of agricultural weeds and pests. While shifting agriculture is generally inefficient compared to alternatives that rely on higher inputs of labor and resources, such systems have sustained humans for thousands of years and still support millions of households throughout the rural tropics.
However, an increase in pressure on a shifting system, such as comes with increased population density or alternative demands for land resources, typically results in a reduction of the length of the regenerative fallow periods. This reduction can have far-reaching consequences, including a loss of forest products and native biodiversity. Most immediately, soil that is exhausted from the harvest period has less time for recover, leading to lower fertility the next time it is cleared, and as a result, much reduced crop yields. This intensification of shifting systems can often then lead to the “extensification” of shifting agriculture, as farmers must clear and cultivate more land under young fallow vegetation to produce the same amount of food that had previously been produced in older (and higher fertility) fallow plots.
This breakdown of shifting cultivation has led to the historical development of numerous innovative practices to increase productivity and more efficiently manage local resources. Many of these innovations are simple changes in management practices, such as the adoption of terracing or mulching, or the encouragement of nitrogen-fixing or otherwise desirable species in the fallow vegetation. Other innovations involve the application of locally available inputs, such as compost, wood ash, charcoal, and lime (calcium carbonate), or the deliberate spatial separation of food and fiber production. While these innovations can dramatically increase the productivity and sustainability of a shifting system, the more common modern response has been to supplement the shortcomings of a stressed system through an increasing reliance on cash cropping, purchased food, imported fiber, and synthetic agrochemicals to supplement plant nutrient requirements and manage agricultural pests.
Shifting cultivation has sustained human settlements in the Solomon Islands for thousands of years and is still found at traditionally low levels of intensification in many rural areas. However, population growth and internal migration towards schools, roads, and other facilities have resulted in the majority of the rural population being supported by recently intensified shifting cultivation. In some places the fallow period is reduced from the traditional 15-20 years to as little as a few months, which can lead to a near complete loss of crop yields and forest products. Imported food, fiber, and even fertilizers are increasingly common in the Solomon Islands, but at the same time a handful of farmers throughout the country are successfully adopting and adapting those alternative innovations that more efficiently make use of local resources. Neither of these responses has yet become dominant in the Solomon Islands and instead the majority of the rural population is simply facing the rapid loss of food security and self-reliance.
The Bushmen Farming Network was officially formed in 2013 to support innovative farmers on the island of Malaita in the Solomon Islands. While this network is indeed a local grassroots non-government organization and it's goals can be defined by the various capitalized catchwords that are common with such efforts—“Organic,” “Sustainable,” “Empowerment,” “Adaptation,” “Smallholder,” and so on—this network was created out of frustration with such talk. Instead, the BFN is focused on immediate action and concrete results, and rather than waiting for international support or novel technological solutions, this group emphasizes six key aspects that have been the foundation to farmer-farmer exchanges for thousands of years. In doing so, the Bushmen Farming Network presents a model of agricultural innovation that is both timely and timeless.
1) Ideas The Bushmen Farming Network is focused on encouraging rural farmers in the Solomon Islands to respond to these pressures through local innovations that encourage self-sufficiency rather than dependence on imported products and the global economy. Doing so is largely a matter of introducing and adapting innovative ideas, which the Bushmen are pursuing through the following activities: testing alternative agricultural and forestry practices , demonstrating integrated best management practices in members' gardens, establishing demonstration gardens in other villages , identifying lead farmers and motivated team members in other villages, mentoring interested farmers at the central farmer field school, supporting innovative farmers through a continuing communication network
2) Tools While “slash-and-burn” can be practiced with simple stone or metal implements, applying alternative techniques require additional tools such as shovels and hoes. Similarly, cultivating forest products efficiently requires saws and pruning shears. Many of the necessary tools are already available throughout the Solomon Islands, but the full value of them is not necessarily obvious and the initial cost can be prohibitive. The Bushmen Farming Network demonstrates the benefits of these additional tools and supplies lead farmers and team members with the hand tools necessary to practice innovative soil management strategies.
3) Planting Materials The Solomon Islands are a hotspot of cultivar diversity, particularly for bananas, edible aroids such as taro, and numerous traditional forest species that make up a historically diverse and resilient food and fiber supply. However, many of these traditional foods and nearly all of the natural fiber products require long fallow periods, either because they are part of the forest vegetation that develops only with sufficient time or because they are dependent on the associated high soil fertility. Many of these traditional species are being lost from the intensified areas under short fallow rotations. Alternative soil management strategies allow for the food species to be grown despite this intensification and alternative land use practices allow for forest products to be managed outside of the fallow rotations. However, while many of the traditionally important species and varieties are not fully lost from the Solomon Islands, they are often difficult to obtain in rural areas facing intensified stress. An associated problem is that introduced species that are critical for innovative practices, such the vetiver grass from Southeast Asia that is essential for contour terracing and the fast growing legume species used for cover cropping, are only slowly making their way through the islands. The widespread adoption of these species is dependent on the introduction, selection, and dissemination of the necessary planting materials, and while many important new species have already been introduced to the Solomon Islands and tested for years at relatively isolated locations, the broader dissemination has not been sufficiently successful. The Bushmen Farming Network combines a rural support and communication infrastructure with the network of lead farmers to aid both the maintenance of traditional varieties and the dissemination of innovative species.
4) Advice The organization of the Bushmen Farming Network consists of three loosely structured tiers. These are 1) lead farmers who carry positions of influence in their local communities and are respected as being both hard-working and innovative, 2) motivated farmers (young or old, male or female) interested in adopting new agricultural practices, and 3) everyone else. The reason for this organization is the pragmatic combination of mentorship and dissemination. For example, if a community member is interested in learning about a new practice that they have seen or heard about, they can ask a local team member who is applying such practices. This team member can in turn refer to the local lead farmer for advice, and these lead farmers can contact each other to share experiences. Such communication can also lead to the exchange of new ideas or practices, which can then quickly be transferred to local team members and through them to other local farmers.
5) Individuality This network does not pretend to be able to tell individuals what is best for them, but rather focuses on exposing farmers to diverse new ideas and providing them with the support necessary to apply them and adapt them as they see fit. The general focus on soil fertility management is particularly fitting to this approach as methods of improving the efficiency of nutrient cycling, for example, can be widely applied. Mulching with organic debris, for example, can moderate soil water and temperature, reduce soil loss through erosion, and provide direct nutrient input through decomposition--and it can do this for stable crops like cassava or cash crops like coffee.
6) Culture Agriculture is not practiced in a vacuum of nutrient cycles and seasons, but as the name implies it is grounded in culture—whatever that might mean to an individual farmer. The majority of the Solomon Islanders have converted to Christianity in the last few generations and some of the members of the Bushmen Farming Network place their agricultural practices in a context of stewardship of Creation. As they like to point out, God had a pretty good little garden going there for a while in early Genesis. But the adoption of Christianity in the Solomons did not come with a vilification of local beliefs and practices the way that it did in much of the world, and most Solomon Islanders, including both strongly Christian and more secular members of the Network, take pride in their local traditions and histories. When it is part of a living culture, this traditional knowledge is the foundation of a deep understanding of agricultural sustainability. Solomon Islanders have an incredible ability to integrate new ideas into a historical context and largely take change in stride, but immanent social changes, such as growing land pressures and the recent movement of young people towards school and towns, are threatening the more categorical shift that has already occurred in much of the world. The older men and women in the Solomons have carried much of the traditional knowledge into the 21st century, but it is neither being well documented nor properly transmitted to the younger generations. Thousands of years of accumulated human knowledge can be lost in a matter of generations and most of it can never be rediscovered. But if such knowledge can be easily lost, it can also be easily maintained through some timely action to preserve it, or better yet, facilitate the integration of new adaptations into this cultural foundation. This is a primary overarching goal of the Bushmen Farming Network.
Three stages of shifting cultivation: an active garden (foreground), young fallow of maybe 4+ years (behind the cassava), and old fallow or primary forest (background).
The hillside behind this fishing village contains mostly young fallow vegetation (light green) and rocks can be seen "coming up" in gardens (white in brown) as a result of excessive erosion. This is likely an area of high stress and declining local production.
The effects of highly intensified shifting cultivation. The foreground is an old garden patch that, after several months of fallow, is not supporting any vegetation. The remaining nutrient-rich organic soil is being lost through erosion and what little remains is accumulating in depressions in an otherwise infertile clay hard pack.
Lionel Maeliu (left), a pioneer of alternative agriculture in the Solomon Islands, discusses his vetiver grass contour system with a visiting farmer.
The Bushmen team at work building a demonstration garden using alternative soil management practices.
John Johnson, an agricultural teacher on Malaita and a long-time lead farmer, uses one of the Bushmen gardens as the basis for a lecture during a field trip.
New ideas can be applied in diverse and creative ways. Here, a fisherman living on a sand bar island created a garden in an old canoe
Casper (far left) learned the traditional Mao style of dancing from his grandfather, and for nearly twenty years he has been mentoring a group of men who have become known throughout the country.