Browsing by Author "Altieri, Miguel A."

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  • Agroecological Principles for Sustainable Agriculture
    Altieri, Miguel A. (2002)
    Agroecology is an applied science, adapting ecological concepts and principles to the design and management of sustainable agroecosystems and providing a framework for assessing the performance of agroecosystems (Altieri, 1995). When fully developed, agroecology does more than inform the selection and use of alternative practices; it helps farmers fashion and maintain agroecosystems that have minimal dependence on expensive chemical and energy inputs. Agricultural systems are supported by interactions and synergies between and among biological components that enable these systems to sponsor their own soil fertility, productivity enhancement and crop protection (Altieri and Rosset, 1995).
  • Agroecology: The Science of Sustainable Agriculture
    Altieri, Miguel A. (Boulder, Co.: Westview Press, 1995)
    Agroecology goes beyond a one-dimensional view of agroecosystems -- their genetics, agronomy, edaphology -- to embrace an understanding of ecological and social levels of coevolution, structure, and function. Agroecology encourages researchers to tap into farmers' knowledge and skills and to identify the unlimited potential of assembling biodiversity to create beneficial synergisms that provide agroecosystems with the ability to remain or return to an innate state of natural stability. Sustainable yield in the agroecosystem derives from the proper balance of crops, soils, nutrients, sunlight, moisture, and other coexisting organisms. The agroecosystem is productive and healthy when these balanced and rich growing conditions prevail and when crop plants remain resilient to tolerate stress and adversity. Occasional disturbances can be overcome by a vigorous agroecosystem which is adaptable and diverse enough to recover once the stress has passed. Occasionally, strong measures (i.e., botanical insecticides, alternative fertilizers, etc.) may need to be applied by farmers employing alternative methods to control specific pests or soil problems. Agroecology provides the guidelines to carefully manage agroecosystems without unnecessary or irreparable damage. Simultaneous with the struggle to fight pests, diseases, or soil deficiency, the agroecologist strives to restore the resiliency and strength of the agroecosystem. If the cause of the disease, pests, soil degradation, and so forth, is understood as imbalance, then the goal of the agroecological treatment is to recover balance. In agroecology, biodiversification is the primary technique to evoke self-regulation and sustainability.
  • The ecological and social tragedy of crop-based biofuel production in the Americas
    Altieri, Miguel A.; Bravo, Elizabeth (Food First/Institute for Food and Development Policy, Oakland, CA, USA., 2007)
    This papers addresses the ecological, social and economic implications of biofuel production. The authors argue that contrary to the false claims of corporations that promote these "green fuels," the massive cultivation of corn, sugar cane, soybean, oil palm and other crops presently pushed by the fuel crops industry - all to be genetically engineered - will not reduce greenhouse gas emissions, but will displace tens of thousands of farmers, decrease food security in many countries, and accelerate the deforestation and environmental destruction of the Global South.
  • Enhancing crop productivity via weed suppression in organic no-till cropping systems in Santa Catarina, Brazil
    Altieri, Miguel A.; Lana, Marcos A.; Bittencourt, Henrique V.; Kieling, André S.; Comin, Jucinei J.; Lovato, Paulo E. (Taylor & Francis Group, 2011)
    In Santa Catarina, southern Brazil, family farmers modified the conventional no-till system by flattening cover crop mixtures on the soil surface as a strategy to reduce soil erosion and lower fluctuations in soil moisture and temperature, improve soil quality, and enhance weed suppression and crop performance. During 2007 and 2008, we conducted three experiments aimed at understanding the processes and mechanisms at play in successful organic conservation tillage systems (OCT), especially the underpinnings of ecological weed suppression, a key advantage of OCT systems over conventional no-till systems. Our results, as well as farmers observations, suggest that cover crops can enhance weed suppression and hence crop productivity through physical interference and allelopathy and also a host of effects on soil quality, fertility, and soil moisture that we did not measure. Results from the three trials indicate that the best cover crop mixture should include a significant proportion of rye, vetch, and fodder radish as these mixtures produce large biomass, and are readily killed by rolling forming a thick mulch sufficient to provide effective weed control in the subsequent vegetable crop. (CAB Abstract)
  • Soil fertility management and insect pests: Harmonizing soil and plant health in agroecosystems
    Altieri, Miguel A.; Nicholls, Clara I. (Elsevier, 2003)
    Cultural methods such as crop fertilization can affect susceptibility of plants to insect pests by altering plant tissue nutrient levels. Research shows that the ability of a crop plant to resist or tolerate insect pests and diseases is tied to optimal physical, chemical and mainly biological properties of soils. Soils with high organic matter and active soil biology generally exhibit good soil fertility. Crops grown in such soils generally exhibit lower abundance of several insect herbivores, reductions that may be attributed to a lower nitrogen content in organically farmed crops. On the other hand, farming practices, such as excessive use of inorganic fertilizers, can cause nutrient imbalances and lower pest resistance. More studies comparing pest populations on plants treated with synthetic versus organic fertilizers are needed. Understanding the underlying effects of why organic fertilization appears to improve plant health may lead us to new and better integrated pest management and integrated soil fertility management designs.