Análisis multivariado de la adopción de tecnologías productivas de cacao: Evidencia de un estudio de caso en Colombia

[EN] Multivariate and ordered Probit models were used to study the determinants of the adoption and extent of adoption of agronomic practices among cacao farmers in Nariño, Colombia, with data from 353 farmers in the mountain region. Results suggest that farmers’ adoption decisions are made on a joint basis, further validating the use of a multivariate approach. The presence of illegal crops creates strong disincentives that affect the possibility of more significant technological improvements. Adequate access to agricultural technical assistance strongly increases rates of adoption. Evidence suggests that efforts are necessary to better target resource-poor farmers.[ES] Se usaron modelos Probit multivariado y ordenado para estudiar los determinantes de adopción e intensidad de adopción de prácticas agronómicas entre cacaoteros de la región de cordillera de Nariño, Colombia, partiendo de datos para 353 productores. Los resultados indican que las decisiones de adopción tecnológica suelen ser simultáneas, validando la aproximación multivariada. La presencia de cultivos ilegales supone una posible barrera de incentivos para lograr mejores indicadores de adopción. Acceso efectivo a asistencia técnica agropecuaria aumenta considerablemente las tasas de adopción. La evidencia sugiere una urgente necesidad de mejorar el alcance de las tecnologías para productores de bajos recursos.This article is a result of the project “Development of a low-cadmium cacao productive model for the mountain region of Nariño”. The authors would like to thank Fundación Ayuda en Acción and Agencia Española de Cooperación Internacional para el Desarrollo (AECID) for funding the project through the Agreement 1980 of 2019 signed with AGROSAVIA, and to technical assistants from Ayuda en Acción for contributing to the survey design and data collection.Martínez, JM.; Martínez Pachón, E. (2021). Multivariate analysis of the adoption of cacao productive technologies: Evidence from a case study in Colombia. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 21(1):79-102. https://doi.org/10.7201/earn.2021.01.04OJS7910221

Cultivo de papa en el suroeste colombiano: tipos de agricultores y eficiencia técnica

Potato is a traditional and economically important crop for farmers in the high mountains of Nariño (Colombia). However, its productivity growth is weakening, injuring farmers’ livelihoods. We hypothesize that an in-depth study of farm typologies and their relationship with productive efficiency could prove helpful in delivering recommendations for sector improvement. With a representative sample of 1,018 farmers, this research used cluster methods to identify representative types of farming and then a stochastic frontier model to build a measure of potato production efficiency. Finally, it analyzed how technical efficiency behaves across the calculated types of farming. Results suggested that four kinds of farming describe potato production in Nariño: micro, small, medium, and large-scale. Most farmers are of the micro (71.8 %) and small scale (23.8 %), and their conditions are unfavorable in terms of access to technical assistance, credit, and improved production practices. Although these farmers report an average efficiency of 79 % and 85 %, respectively, there is still an opportunity for improvement. We close with a brief discussion that focuses on suggestions for future policy or research advances around these farmers.La papa es un cultivo de tradición y relevancia económica para los agricultores de montaña en Nariño (Colombia). Sin embargo, el crecimiento de su producción reporta un aparente estancamiento, lo cual podría poner en riesgo a los productores paperos. Un estudio a profundidad de las tipologías de producción y su conexión con la eficiencia productiva pueden ser clave para brindar recomendaciones con base en la evidencia. Partiendo de una muestra representativa de 1018 paperos, esta investigación usa métodos de clúster para identificar tipologías de hogares productores, para luego ajustar una frontera estocástica que permite crear una medida de eficiencia técnica. Por últimos, se analizó la forma en que la eficiencia técnica varía a través de las tipologías identificadas. Los resultados mostraron que cuatro tipos de producción describen a los paperos de Nariño: micro, pequeños, medianos y grandes productores. La mayoría de estos son de escala micro (71,8 %) y pequeña (23,8 %), y sus condiciones son desfavorables en lo que respecta a acceso a asistencia técnica, crédito y adopción de prácticas agronómicas mejoradas. Aunque estos productores presentan niveles medios de eficiencia de 79 % y 85 %, respectivamente, aún hay posibilidades de mejora. El documento cierra con una breve discusión que se enfoca en sugerir futuros trabajos de investigación o política alrededor de estos productores

Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises

Effect of native forest remnants on biological control and production in traditional corn (Zea mays L.) crops

The expansion of the agricultural frontier is one of the main causes of biodiversity loss and detriment of ecosystem services essential for agricultural production, including biological pest control. In this work, the relationship between the loss of native forest cover, diversity of arthropods and weeds in crops and its relationship with herbivory and crop production was examined, using twelve traditional corn crop fields in Topaipí (Cundinamarca) during the second growing season in 2011. In the studied cornfields pest control was provided by native predators and parasitoids, which in turn depended upon the maintenance of the diversity of weeds within crops. Forest cover promoted complexity of networks of plant-arthropod in this system, in which the richness of predators was associated with increased production of crops. Therefore, the conservation of forests in traditional crop systems is essential for biological control, production and biodiversity conservation.Resumen. La expansión de la frontera agrícola es una de las principales causas de pérdida de la biodiversidad y detrimento de las funciones ecosistémicas esenciales para la producción agrícola, entre ellas el control biológico de plagas. En este trabajo, se evaluaron las relaciones entre la pérdida de cobertura de los bosques nativos, la diversidad de arvenses y artrópodos dentro de los cultivos y su relación con la herbivoría y la producción en doce cultivos tradicionales de maíz en Topaipí (Cundinamarca), durante la segunda temporada de siembra de 2011. En los cultivos estudiados el control biológico de plagas fue proporcionado por predadores y parasitoides nativos, y estos a su vez dependieron del mantenimiento de la diversidad de arvenses dentro de los cultivos. La cobertura de bosques promovió la complejidad de las redes de interacción plantas-artrópodos en este sistema, en los que la riqueza de depredadores se asoció con una mayor producción de los cultivos. Por lo anterior, la conservación de los bosques en sistemas de cultivos tradicionales es esencial para el control biológico, la producción y la conservación de la biodiversidad.Doctorad

Multivariate analysis of the adoption of cacao productive technologies: Evidence from a case study in Colombia

Multivariate and ordered Probit models were used to study the determinants of the adoption and extent of adoption of agronomic practices among cacao farmers in Nariño, Colombia, with data from 353 farmers in the mountain region. Results suggest that farmers’ adoption decisions are made on a joint basis, further validating the use of a multivariate approach. The presence of illegal crops creates strong disincentives that affect the possibility of more significant technological improvements. Adequate access to agricultural technical assistance strongly increases rates of adoption. Evidence suggests that efforts are necessary to better target resource-poor farmers.Se usaron modelos Probit multivariado y ordenado para estudiar los determinantes de adopción e intensidad de adopción de prácticas agronómicas entre cacaoteros de la región de cordillera de Nariño, Colombia, partiendo de datos para 353 productores. Los resultados indican que las decisiones de adopción tecnológica suelen ser simultáneas, validando la aproximación multivariada. La presencia de cultivos ilegales supone una posible barrera de incentivos para lograr mejores indicadores de adopción. Acceso efectivo a asistencia técnica agropecuaria aumenta considerablemente las tasas de adopción. La evidencia sugiere una urgente necesidad de mejorar el alcance de las tecnologías para productores de bajos recursos

Multivariate analysis of the adoption of cacao productive technologies: Evidence from a case study in Colombia

[EN] Multivariate and ordered Probit models were used to study the determinants of the adoption and extent of adoption of agronomic practices among cacao farmers in Nariño, Colombia, with data from 353 farmers in the mountain region. Results suggest that farmers’ adoption decisions are made on a joint basis, further validating the use of a multivariate approach. The presence of illegal crops creates strong disincentives that affect the possibility of more significant technological improvements. Adequate access to agricultural technical assistance strongly increases rates of adoption. Evidence suggests that efforts are necessary to better target resource-poor farmers. [ES] Se usaron modelos Probit multivariado y ordenado para estudiar los determinantes de adopción e intensidad de adopción de prácticas agronómicas entre cacaoteros de la región de cordillera de Nariño, Colombia, partiendo de datos para 353 productores. Los resultados indican que las decisiones de adopción tecnológica suelen ser simultáneas, validando la aproximación multivariada. La presencia de cultivos ilegales supone una posible barrera de incentivos para lograr mejores indicadores de adopción. Acceso efectivo a asistencia técnica agropecuaria aumenta considerablemente las tasas de adopción. La evidencia sugiere una urgente necesidad de mejorar el alcance de las tecnologías para productores de bajos recursos

Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases.

Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises