Miguel A Altieri ^1* Clara I Nicholls ¹ René Montalba ² Lorena Vieli ² Luis Ladislao Vazquez ³

• ¹ University of California, Berkeley, Berkeley, United States
• ² University of La Frontera, Temuco, Araucania, Chile
• ³ Centro LatinoAmericano de Investigaciones Agroecologicas (CELIA), Colombia, Medellin, Colombia

Given the unpredictability, frequency and severity of climatic events, it is crucial to determine the adaptation limits of agroecological strategies adopted by farmers.In times of drought smallholders' farmers cope with stress using a series of crop diversification and soil management strategies. Intercropping and agroforestry systems complemented with mulching and organic matter applications can increase water storage, enhancing crops' water use efficiency. Although an overwhelming number of studies demonstrate that these agroecological designs and practices are associated with greater farm-level resilience, it is important to recognize the limits of resilience. The aim of this paper is to assess the limitations of agroecological practices in enhancing the ability of agroecosystems to adapt to climate change under extended drought stress which may overwhelm crops'adaptation response. A set of agroecological practices that can extend such limits under prolonged water stress scenarios are described. Two methodologies to assess farms' resilience to drought provide useful tools, as they can assist farmers and researchers in identifying the practices and underlying mechanisms that reduce vulnerability and enhance response capacity allowing certain farm systems to better resist and/or recover from droughts. Clearly, reducing farmers exposure to drought requires collective actions beyond the farm scale ( i.e. restoring local watersheds to optimize local hydrological cycles) aspects not Deleted: e Deleted: against climatic extremes Deleted: has limits delineated by capacity thresholds, after which climate damages may Deleted: the Deleted: , especially when extended climatic stress reaches the tipping points leading to irreversible consequences Deleted:Deleted: In times of drought many smallholders' farmers cope with stress using a series of crop diversification and soil management strategies. Intercropping and agroforestry systems complemented with mulching and copious organic matter applications can increase water storage, leading to increased and water use efficiency (WUE) thus extending the crop cycle under extended drought periods. Scientific evidence suggests that these practices can extend the limits beyond the established thresholds, but up to a point if the event is too prolonged Deleted: . Two methodologies that assess farms' resilience to drought are described. R Deleted: , such as Deleted: Farmers' ingenuity and management skills are key to confront disasters, however,