Agroecology is a science that applies ecological concepts and principles to the design and management of sustainable agricultural ecosystems. Inspired by the diversified models of traditional agriculture, agroecologists promote crop diversification (polycultures, crop-livestock combinations, rotations, agroforestry systems, etc.) as an effective agroecological strategy for introducing more biodiversity into agroecosystems, which in turn provides a number of ecological services to farmers, such as natural soil fertility, pest regulation, pollination, and others. The agroecological approach involves the application of blended agricultural and ecological sciences with indigenous knowledge systems. A variety of agroecological and participatory approaches have shown in many rural areas very positive outcomes, even under adverse environmental and socioeconomic conditions. Potentials include raising crop yields and total farm output, increasing stability of production through diversification, enhancing resilience of farms to climate change, improving diets and income, and conservation of the natural resource base and biodiversity. Agroecological principles can also be applied to break the monoculture nature of modern mechanized farms. Strategies include complex crop rotations, cover cropping in vineyards and fruit orchards, strip intercropping, and so on. The ultimate goal is to develop integrated diversified and resilient agroecosystems with minimal dependence on external, off-farm inputs.
Miguel A. Altieri
Noa Kekuewa Lincoln and Peter Vitousek
Agriculture in Hawaiʻi was developed in response to the high spatial heterogeneity of climate and landscape of the archipelago, resulting in a broad range of agricultural strategies. Over time, highly intensive irrigated and rainfed systems emerged, supplemented by extensive use of more marginal lands that supported considerable populations. Due to the late colonization of the islands, the pathways of development are fairly well reconstructed in Hawaiʻi. The earliest agricultural developments took advantage of highly fertile areas with abundant freshwater, utilizing relatively simple techniques such as gardening and shifting cultivation. Over time, investments into land-based infrastructure led to the emergence of irrigated pondfield agriculture found elsewhere in Polynesia. This agricultural form was confined by climatic and geomorphological parameters, and typically occurred in wetter, older landscapes that had developed deep river valleys and alluvial plains. Once initiated, these wetland systems saw regular, continuous development and redevelopment. As populations expanded into areas unable to support irrigated agriculture, highly diverse rainfed agricultural systems emerged that were adapted to local environmental and climatic variables. Development of simple infrastructure over vast areas created intensive rainfed agricultural systems that were unique in Polynesia. Intensification of rainfed agriculture was confined to areas of naturally occurring soil fertility that typically occurred in drier and younger landscapes in the southern end of the archipelago. Both irrigated and rainfed agricultural areas applied supplementary agricultural strategies in surrounding areas such as agroforestry, home gardens, and built soils. Differences in yield, labor, surplus, and resilience of agricultural forms helped shape differentiated political economies, hierarchies, and motivations that played a key role in the development of sociopolitical complexity in the islands.
Research during the late 20th and early 21st centuries found that traces of human intervention in vegetation in Southeast Asian and Australasian forests started extremely early, quite probably close to the first colonization of the region by modern people around or before 50,000 years ago. It also identified what may be insubstantial evidence for the translocation of economically important plants during the latest Pleistocene and Early Holocene. These activities may reflect early experiments with plants which evolved into agroforestry. Early in the Holocene, land management/food procurement systems, in which trees were a very significant component, seem to have developed over very extensive areas, often underpinned by dispersal of starchy plants, some of which seem to show domesticated morphologies, although the evidence for this is still relatively insubstantial. These land management/food procurement systems might be regarded as a sort of precursor to agroforestry. Similar systems were reported historically during early Western contact, and some agroforest systems survive to this day, although they are threatened in many places by expansion of other types of land use. The wide range of recorded agroforestry makes categorizing impacts problematical, but widespread disruption of vegetational succession across the region during the Holocene can perhaps be ascribed to agroforestry or similar land-management systems, and in more recent times impacts on biodiversity and geomorphological systems can be distinguished. Impacts of these early interventions in forests seem to have been variable and locally contingent, but what seem to have been agroforestry systems have persisted for millennia, suggesting that some may offer long-term sustainability.
Glenn H. Shepard Jr., Eduardo Neves, Charles R. Clement, Helena Lima, Claide Moraes, and Gilton Mendes dos Santos
The tropical lowlands of South America were long thought of as a “counterfeit paradise,” a vast expanse of mostly pristine rainforests with poor soils for farming, limited protein resources, and environmental conditions inimical to the endogenous development of hierarchical human societies. These misconceptions derived largely from a fundamental misunderstanding of the unique characteristics of ancient and indigenous farming and environmental management in lowland South America, which are in turn closely related to the cultural baggage surrounding the term “agriculture.” Archaeological and archaeobotanical discoveries made in the early 21st century have overturned these misconceptions and revealed the true nature of the ancient and traditional food production systems of lowland South America, which involve a complex combination of horticulture, agroforestry, and the management of non-domesticated or incipiently domesticated species in cultural forest landscapes. In this sense, lowland South America breaks the mould of the Old World “farming hypothesis” by revealing cultivation without domestication and domestication without agriculture, a syndrome that has been referred to as “anti-domestication”. These discoveries have contributed to a better understanding of the cultural history of South America, while also suggesting new paradigms of environmental management and food production for the future of this critical and threatened biome.