ESTUDIO DE DIVERSIDAD AGRÍCOLA EN FINCAS DE LA HABANA.

At present, there is a world worry about restoring and preserving biodiversity, either in natural areas or anthropized agricultural systems. After the Green Revolution had appeared, a high-input monoculture was established in large areas, which caused ecosystem biodiversity erosion, particularly farmers' managed agrodiversity, besides increasing greenhouse gas emissions (GEI), as a result of using technological packages and farm misuse. Our country was not free from this process and when the socialist field had fallen down, Cuba was immersed into a general food crisis facing the challenge of looking for low-input solutions. Since 2001, the participatory plant breeding staff has delivered the farmers some crop varieties kept in germplasm banks from the national institutions. This study was carried out in 14 farms from Havana province, where Shannon Weaver and Margalef's diversity indexes were calculated for producers' agricultural species, either linked or not to the project. Also, through IPCC-2001 methodology, methane and nitrous oxide emissions from these productive systems were estimated, in order to know their relationship to agrodiversity. Results proved that diversity indexes are highly correlated in every farm studied, depending on the number of species preserved by farmers. Nitrous oxide emissions are strongly correlated with the amount of nitrogenous fertilizers applied to the farm and, in case of methane, as there were different sources of emission, besides not being present in every farm, it did not show any correlation with agrodiversity or with another aspect measured in the farms. Those farms with more diversity had low greenhouse gas emissions, which indicates that an adequate agrodiversity management in the farms reduces emissions by agricultural practices. [ABSTRACT FROM AUTHOR]