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.