FAO, 2007). Yet even more important for the purposes of this evaluation, agroecological and “knowledge-intensive” agriculture offers the peasants and small-scale producers of LAC an alternative for the production not only of food, but of culture and human and social capital (Zinin et al., 2000; Pretty et al., 2003). Agroecological experiences in the region provide evidence of the potential of ecological agriculture to pull peasants out of poverty, strengthen social relations, eliminate dependency on outside inputs and knowledge and strengthen the connection with their environment. A recent report by the FAO (2007) that came out of the FAO-sponsored conference Organic Agriculture and Food Security in 2007, concludes that organic systems have a great potential to increase food access, reduce risk and build long-term investment that increase food security, all of which directly address development and sustainability goals. It also states that when total household yield and nutritional and environmental impacts are measured along with the cost-effectiveness of production, as well as energy efficiency, organic systems are superior to conventional systems.
     Since the early 1990s, organic agriculture has experienced a leap in demand, which has induced a spectacular increase, representing one the areas of agriculture with the greatest commercial potential (Box 1-11).
1.7.2 Sustainability
1.7.2.1 Traditional/indigenous system
The sustainability of an agricultural system has to do with obtaining the best possible result without compromising the resource base looking to the future. The concept of sustainable agriculture integrates goals such as protecting the environment, profitability or productivity and maintenance of rural communities (Altieri, 1995). For a long time, anthropologists and ecologists have recognized the sustainability features of indigenous/traditional systems and these systems have been the basis of knowledge for the development of modern agroecology (Steward 1955; Netting, 1974; Altieri, 1995). Several specific aspects of traditional and indigenous agricultural systems tend to make them more sustainable and conducive to conserving biodiversity on and around farms. Traditional farmers have generally relied on a mosaic of fields, pasture and forests to provide the full range of their subsistence needs, which produces a variety of habitat for wild biodiversity (Altieri, 1995; McNeely and Scherr, 2003). Agricultural diversity is greater, thus providing different habitat options to biodiversity: more types of crops tend to be grown and several crops may be grown together, or intercropped. Trees are often left standing in some agricultural fields or pastures. Cultivation is usually less intensive and, in the case of the swidden agricultural systems typical of indigenous cultivation in the humid tropics in Latin America, fields are allowed to return to secondary vegetation for a considerable period after a few years of cultivation. The patchwork of land uses and in some cases use of intercropping, reduces erosion and thus sedimentation of streams and rivers. And because these farming systems use fewer or no agricultural chemicals, they also cause less pollution.
     Although these traditional systems maintained and still maintain hundreds of generations of farmers, some (such

 as the chinampas in Mexico and the camellones elevados in Lake Titicaca in Peru and Bolivia) were not able to survive and others are in the process of disappearing due to social, economic and political pressures (Denevan 1980; Turner and Harrison, 1983; Wilken, 1987). As the crisis of rural livelihoods advances, these systems gradually disappear and with them the genetic resources and knowledge and wisdom that evolved over millennia.
1.7.2.2 Conventional/productivist system
The greatest criticism of the conventional/productivist system is that it is not environmentally sustainable. The advent of high-input agriculture has led to a simplification and homogenization of the system, which results in the loss of planned biodiversity (in other words, the diversity of crops and other productive organisms such as honey bees, fish for food and others). The reduction of planned diversity results in a diminution of the associated diversity (that is, all the other organisms that live in that agroecosystem). The loss of biodiversity has negative consequences for the sustainability of the agroecosystem, as it has a direct impact on ecological processes as well as on the environmental services provided by ecosystems (Naeem et al., 1994; Altieri, 1995; Tilman et al., 1996; Matson et al., 1997; Yachi and Loreau, 1999; Reganold et al., 2001). Some of the ecosystem services that are degraded by modern production practices are essential to the viability and sustainability of the agricultural systems themselves (McNeely and Scherr, 2002). Soil fertility is a prime example. There is increasing evidence that the rich and complex below-ground ecosystems of bacteria, fungi, protozoa, nematodes, arthropods, earthworms and other organisms play a critical role in creating and maintaining the soil conditions that are optimal for agricultural production (Buck et al., 2004). Production practices used in the conventional/productivist system, which are dependent on chemical inputs and mechanical manipulation of soils,
can have devastating effects on these important but littleunderstoodecosystems. Erosion caused by tillage and other production practices, such as leaving bare soil exposed between planting seasons, has also gravely affected soil fertility (Buck et al., 2004).
     Pollination is another key ecosystem service that can be seriously degraded in intensive agricultural landscapes. Studies in Costa Rica, Brazil and Argentina have shown that more pollinators are found in agricultural fields adjacent to forest fragments or remnants of native vegetation and that more pollen deposition actually occurs in those sites (De Marco and Monteiro Coelho, 2004; Ricketts et al., 2004; Chacoff and Marcelo, 2006). Also systems that are more diverse and harbor high levels of bee species increase pollination services (Klein et al., 2003; Steffan-Dewenter et al., 2005). Finally, it is also clear that use of agrochemicals can reduce the number of beneficial organisms available both for pollination and for control of crop pests (Buck et al., 2004).

     The use of pesticides in conventional/productivist agriculture has also had a negative impact on the other beneficial fauna, such as natural enemies (predators, parasitoids and others), stimulating the evolution of resistance in pests, the resurgence of primary pests and outbreaks of secondary pests (Nicholls and Altieri, 1997). This so-called “pesticide