[en] The aim of this Ph. D. thesis was to assess various indicators to measure the sustainability of fields owned by some producers of cacao in the province of El Oro-Ecuador taken into account economic, social and environmental dimensions. The population studied consisted of fields cultivated with CCN51 (n=49) and cacao National (n=24), where, first a survey has been performed to obtain economic and social indicators. The environmental indicators were obtained from 30 soil samples, selected from the whole population studied, and these samples have been collected in the first 30 cm. Subsequently, the soil physicochemical properties were analysed for obtaining an index of soil (ISQ). The studied soils belonged to the Alfisols, Inceptisols and Entisols orders. Principal component analysis has been applied using an adimensional procedure, after normalisation of the selected indicators between 0 and 1. To verify the effects of agronomical management on organic matter (MO) content analysis stable isotopes13C and 15N have been performed and the degrees of aromaticity versus aliphaticity have been characterised by means of infrared spectroscopy of infrared (IR), in soil and cacao litter. The main results from the economic point of view were the production of the cacao type CCN51 (2337.63 Kg ha-1) and the resulting earned income ($1204) that were higher than those corresponding to the cacao National (476.92 Kg ha-1 versus $919.68). Considering the social aspect, 32.88% of the field owners were of more than 60 years of age and 53% had primary education. The soil properties of showed predominance of silt and clay contents, with mean values of soil organic matter (MO) lower than 3% and mean pH=6,9; no statistical differences were appreciated between soil order or cacao type. The cation exchange capacity (CEC), sum of bases (SB), pH, organic C, available phosphorus (P) sand, silt and clay contents were the properties selected as Indicators of Soil Quality (ISQ). The averages of 13C (-25.11‰) and 15N (8.8‰) corresponded to thresholds of moderate application of synthetic fertilizers. The soil IR spectra indicated aromaticity in the region 1650 cm-1, whereas for the litter, the features observed in the region around 2950 cm-1 indicated typical peculiarities of the aliphatic groups. In average the value of normalised indicators was 0.52, so that the studied fields can be ranked in the class of week sustainability.

[es] El objetivo de la tesis fue inferir varios indicadores por dimensiones económica, social y ambiental para medir la sostenible de algunos productores de cacao en la provincia del El Oro-Ecuador. La población estuvo conformada por fincas cultivadas de cacao CCN51 (n=49) y Nacional (n=24), a los que se aplicó una encuesta para obtener los indicadores económicos y sociales. Los indicadores ambientales fueron obtenidos de 30 muestras de suelo provenientes de la población en estudio, las cuales fueron tomadas a 30 cm de la superficie, y posteriormente sus propiedades físico-químicas fueron analizadas para establecer un índice de calidad del suelo (ICS). Por dimensión se aplicó un análisis de componentes principales y de normalización entre cero a 1 de los indicadores. Para verificar la incidencia del manejo agronómico, la aromaticidad y alifáticidad de la materia orgánica (MO) se realizaron análisis de 13C,15N e Infrarrojo (IR), al suelo y hojarascas de cacao. Los resultados que destacaron en la dimensión económica fue el rendimiento del tipo de cacao CCN51 (2337,63 Kg ha-1) e ingresos ($1204), que fueron superior al cacao Nacional (476,92 kg ha-1; $919,68). En lo social el 32,88% de los propietarios de los predios fueron >60 años de edad y un 53% tenían estudios de primaria. Los indicadores ambientales mostraron predominio del limo y la arcilla, con medias de MO <3% y 6,9 pH en suelo, sin mostrar diferencia estadística por orden de suelo y tipo de cacao. La de bases, CIC, pH, C, arena, P, limo y arcilla fueron los indicadores seleccionado en el ICS. Las medias de 13C (-25,11‰) y 15N (8,8‰) correspondieron a umbrales de modera aplicación de fertilizante sintéticos. Los espectros IR en suelo indico aromaticidad en la región 1650 cm-1, para hojarasca se observó en la región en 2950 cm-1 al grupo alifático C-H. El promedio de los indicadores normalizados fue 0,52 que se clasifica como débil sostenibilidad.