Browsing by Author "Miranda, R."

Now showing 1 - 8 of 8
  • Caracterización de suelos según su Índice de fertilidad y capacidad de uso en El Municipio de Ancoraimes
    Mamani, B.; Miranda, R.; Montavalli, P.; Cusicanqui, Jorge (2007)
    El presente trabajo de investigación se viene desarrollando en el Municipio de Ancoraimes, correspondiente al Altiplano Norte de la Provincia Omasuyos del Departamento de La Paz. Los objetivos son: caracterizar los suelos de tres comunidades del municipio de Ancoraimes - Chinchaya, Cohani y Chojñapata; y determinar la fertilidad y uso actual de la tierra. Para el presente estudio se elaboró mapas en base a imágenes satelitales, donde se realizo un análisis del paisaje y subpaisaje los que fueron corroborados con trabajos de campo; los parámetros que se tomaron en cuenta fueron la pendiente, cobertura vegetal, uso actual del suelo, análisis del clima e influencia del mercado en el uso de la tierra. Se realizó la obtención de muestras de suelo para determinar el nivel de la fertilidad cada unidad identificada. Las muestras de suelo se obtuvieron de acuerdo a protocolos de muestreo que, en la siguiente fase serán analizadas en laboratorio. De acuerdo a los resultados se ha identificado que las comunidades se encuentran ubicadas dentro de la Provincia Fisiográfica: Altiplano, Gran Paisaje: Montaña, presentando 12 unidades a nivel de paisaje en los que figuran los valles bajos, valles altos, pie de montes, ladera, depresiones y zonas montañosas. El uso de la tierra en estas unidades está determina por las condiciones climáticas y mercado. Los primeros resultados mostraron que en las comunidades de altura como Koani y Chojñapata la actividad primordial de los comunarios es la ganadería de camélidos y ovinos, siendo la agricultura una actividad secundaría, mientras que en las comunidades bajas como Chinchaya, donde influye la cercanía a los mercados de ciudad de La Paz, la principal actividad es agrícola basada en la producción de cultivos de cebolla, haba y papa.
  • Changes in soil organic C and N due to climate change and socioeconomic factors in potato-based cropping systems in the Bolivian Highlands
    Motavalli, Peter P.; Aguilera, Javier; Valdivia, Corinne; García, Magali; Jiménez, Elizabeth; Cusicanqui, Jorge; Miranda, R. (Madison, WI: American Society of Agronomy, 2007)
    Global climate change and changes in migration and market conditions in the Bolivian Highlands (Altiplano) have reduced the use of traditional cropping practices and increased the risk of crop failure and food insecurity. The objectives of this research were to survey indigenous farming communities in the northern Altiplano of Bolivia to determine the actual and perceived changes in cropping practices in potato-based cropping systems and to assess the effects of these changes on soil total organic carbon (C) and total nitrogen (N) levels and the availability and composition of soil amendments. Village-level surveys were conducted using questionnaires and participatory techniques in 2006-2007 in four communities that were selected to represent communities situated at relatively low and high altitudes in the region. Samples of soil amendments, primarily animal manures, were obtained from each community to determine the range of composition of the materials. In addition, soil samples were collected to a 20 cm depth from agricultural fields that represented different stages of the common agricultural rotation practiced in the region and that had different lengths of fallow periods. A hypothesis of this research is that climate change and socioeconomic factors have caused lower soil total organic C and total N levels due to increased intensity of land use and the amount and type of tillage, and a decrease in the length of the fallow period that was traditionally used to restore soil fertility. The results of the analysis of the soil amendments and soils will be compared to community perceptions of changes in soil quality and management and any differences among the communities will be discussed. The findings of this research will assist in determining if appropriate management practices need to be identified to improve soil organic matter in order to possibly mitigate negative effects of climate change in the area.
  • Differences in cropping systems and soil organic carbon due to climate change and socioeconomic factors in potato-based cropping systems in the Bolivian Highlands
    Motavalli, Peter P.; Cusicanqui, Jorge; Aguilera, Javier; Valdivia, Corinne; García, Magali; Jiménez, Elizabeth; Miranda, R. (2008)
    This presentation presents results of differences in cropping systems and soil organic carbon in the Bolivian Highlands, due to climate change and socioeconomic factors in potato-based cropping systems.
  • Differences in cropping systems and soil organic carbon due to climate change and socioeconomic factors in potato-based cropping systems in the Bolivian highlands
    Motavalli, Peter P.; Cusicanqui, Jorge; Aguilera, Javier; Valdivia, Corinne; García, Magali; Jiménez, Elizabeth; Miranda, R. (2008)
    This presentation discusses research performed in Bolivia on climate change in regard to soil degradation. Through interdisciplinary methods in soil science and social science, the researchers attempted to determine why and how much livelihoods have changed in the Bolivian highlands. Specifically, the researchers were interested in the climate and human interface and how this has been affected by reduced rainfall and climate change.
  • Efecto de aplicación de abonos orgánicos y químicos sobre la fertilidad del suelo en el cultivo de la papa (Solanum tuberosum) en el Altiplano Norte de la Paz
    Herrera, E. A.; Miranda, R.; Motavalli, Peter P.; Peñaranda, M. (2007)
    El trabajo de Enmiendas orgánicas se desarrolla en tres comunidades del municipio de Ancoraimes (Cohani, Chinchaya y Chojñapata), correspondiente a la provincia Omasuyos del departamento de La Paz. Los objetivos de la presente investigación son determinar la influencia de los abonos orgánicos y químicos en el desarrollo del cultivo de la papa y sus efectos sobre los suelos, para de esta manera proponer alternativas de manejo de materia orgánica. Para la presente investigación se utilizo estiércol de ganado vacuno y ovino, además de fertilizantes químicos como la urea y fosfato de amonio. Los resultados muestran que los diferentes tratamientos no son significativos en cuanto a la acumulación de humedad por parte del suelo, mientras que la densidad aparente del suelo bajo en los tratamientos donde se puso materia orgánica. En cuanto al desarrollo del cultivo se observan diferencias numéricas en cuanto a la altura de planta, mas no son estadísticamente significativas. En cuanto al rendimiento, se pudo observar que los tratamientos que contienen una mezcla de estiércol con fertilizantes químicos dieron los mejores resultados. A la fecha se siguen tomando datos de humedad del suelo y densidad aparente, asimismo falta la cosecha en la comunidad de Chojñapata, para realizar la evaluación de rendimiento. Según la percepción de los agricultores, el mejor tratamiento es la mezcla de estiércol de oveja con urea y fosfato de amonio, sin embargo estadísticamente no presentan diferencias significativas.
  • Enmiendas orgánicas e inorgánicas y la fertilidad del suelo en el cultivo de la papa (Solanum tuberosum)
    Miranda, R. (2007)
    A presentation of the SANREM CRSP Andes (LTR-4) project's objectives, areas of action, methodology, experimental designs, activities and preliminary results.
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    Management of organic and inorganic soil fertility inputs in indigenous agricultural communities in the Bolivian Highlands
    Aguilera, Javier; Miranda, R.; Motavalli, Peter P.; Tangara, E.; Herrera, E. A. (2008)
    The Bolivian highland plateau region (Altiplano) is a semi-arid region in the Andes Mountains that has a range in elevation of between 3600 and 4300 m above sea level. The region's climate is characterized by high diurnal temperature variations, frost risks, low and irregular precipitation and high risks of drought during the growing season (Garcia et al., 2007). Recent research has indicated that the Andes region will experience temperature increases of up to 6 degrees C by the end of the century (Bradley et al., 2006, IPCC, 2007). In addition, a consequence of global climate change has been and will be a higher incidence of extreme weather events (Haylock et al., 2006; Thibeault et al., 2008). These climate changes may increase the risk of crop failure and food insecurity of local indigenous communities in the region. Other economic and social changes in the region, such as urban migration, have also impacted agricultural practices in this region, which are primarily potato-based cropping systems and livestock rearing of cows, sheep and camelids (e.g., alpaca and lama) (Valdivia et al., 2001). Research in the Altiplano has indicated that one consequence of climatic and socioeconomic changes has been increased soil degradation (Swinton and Quiroz, 2004; Motavalli et al., 2008). An important component of soils that may assist in mitigating this soil degradation is soil organic matter (SOM) or soil total organic carbon (SOC). Increased soil organic matter generally improves soil quality and the long-term sustainability of agroecosystems (Gupta et al., 1994). Improvements in existing soil management practices or the introduction of alternative practices that increase SOM may be needed for increased production and for reducing the negative consequences of climate change.
  • Soil Metagenomics to identify indicators of soil degradation in the Bolivian Highlands
    Gomez, L.; Jumpponen, A.; Herman, M.; Garrett, Karen A. (2008)
    The Bolivian Highlands (approximately 4000 masl) are experiencing changes in agricultural practices due in part to climate change and economic pressures. Traditional fallow periods are being shortened in an effort to increase yield, but this may be at the expense of soil quality. We will study soil microbial metagenomics using pyrosequencing methods, which allow us to place hundreds of thousands of individual microbes in taxonomic categories. Our goal is to identify microbes that may serve as indicators for the process of soil degradation and to understand the response of soil microbial communities to changing land management practices.