Low External Input Sustainable Agriculture (LEISA) is receiving increased attention, both as a sustainable alternative to Green Revolution-like strategies making intensive use of external inputs, and as a strategy of sustainable agriculture in resource-poor environments where no or very few external inputs are used. The evaluation of LEISA field-experiences in the Philippines and in Ghana shows that the potential of LEISA to improve ecological and/or socioeconomic sustainability depends on site-specific factors in the first place. In areas with a high production potential, LEISA can simultaneously improve ecological sustainability and farmers' socioeconomic conditions by reduced use of external inputs. In areas with a low production potential, LEISA can stabilize and restore the carrying capacity, but generally has limited potential to improve socioeconomic conditions for growing populations, and an increased production may also result from a further depletion of natural resources, and by a limited number of farmers. Other factors that can influence the potential and the applicability of LEISA are the production dip and the rehabilitation period involved, high labour requirements, land ownership aspects, gender issues, constraints to implement a participatory technology development approach, macroeconomic aspects, government influences and information dissemination. Together with the site-specific conditions, these aspects should be considered in planning and evaluation of LEISA techniques.
The Green Revolution shaped the population structure of the rice pathogen Xanthomonas oryzae pv. oryzae