Browsing by Author "Aguirre de Juana, Angel Javier"

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Evolution of argoma shrubland (Ulex gallii Planch.) after clearing and burning treatments in Sierra de Aralar and belate (Navarra)
(2019) Gómez García, Daniel; Aguirre de Juana, Angel Javier; Lorda López, Mikel; Remón, J l
All rights reserved. Shrub encroachment is considered one of the greatest threats in the conservation of pastures, especially in abandoned territories and territories with low stocking density. However, in the Navarra Pyrenees and Basque mountains, with a high stocking density maintained during the last decades, the expansion of argoma shrubland (Ulex gallii), shows that grazing is not enough for its control and requires evaluating measures of clearing. To evaluate the efficiency of the burning and the mechanical clearing (with two treatments: at ground level and 10 cm above ground) in the control of the shrub, these treatments were applied in different plots of encroached grasslands in two pastoral territories (Sierra de Aralar and Belate). After the burning and clearing, the evolution of the shrub was compared in the cleared plots closed to grazing and in their replicas open to it. The results showed differences between the different treatments in both territories that may be related to the initial coverage of the shrubland. In general, burning was less effective in controlling shrubland and allowed a greater resprout than mechanical clearing. No significant differences were found between the two types of mechanical clearing (at ground level and at 10 cm above ground) . Finally, grazing caused a delay in the recovery of the shrub in all cases, but it was not able to eliminate the shrubs completely. From the field observations, the opinions of the farmers and the results of similar experiences, some measures for grassland management were collected and discussed to correct or complement the clearing treatments in order to increase their efficiency.
Ganancias de peso vivo en novillas que pastan Kikuyo (Pennisetum clandestinum, Ex Chiov) fertilizado con pollinaza
(2019) Arcos Álvarez, Cristian Neptali; Lascano Armas, Paola J.; Guevara Viera, Raúl Victorino; Atzori, Alberto S.; Molina Molina, Elsa; Torres Inga, Carlos Santiago; Carmilema Asmal, Johny Fernando; Serpa García, Víctor Guillermo; Aguirre de Juana, Angel Javier; García Zumalacarregui, Jorge Alejandro
The objective of the study was to evaluate the effect on the Kikuyo pasture and the growth of Holstein vaconas of different doses of Pollinaza as organic fertilizer. The work was carried out in a dairy system of 21.6 ha in the province of Cotopaxi in Ecuador, located at 2º 13' North and 78º 24'W at 2651 masl. Rainfall averages 1103 mm I year and temperatures between 14-21 oC. The research compared three levels of organic fertilization with pollinaza (O, 50 and 100 kg/ha/year, represented as FO, F50 and F100) in pastures of Kikuyo Heifers of 210 kg of live weight were used and the conception of the work was like a system to generate animals ready for reproduction. The fertilizers were applied manually in each season for the highest doses. Dry sprinkler irrigation was applied. Rational grazing was used for the delivery of two grass I day strips. The rest time was 21-28 days throughout the period. Balanced supplementation was used at a rate of 1 kg I per heifer I day. Own cut forage was used. The botanical composition was determined. The dry matter availabilites were determined with 1O frames per pasture and 30 height observations. The average vaconas gains, final weight and expenses I vacona ($) were measured, differences were found (p <0.05) in favor of the F100 treatment and its population increases to 93.7% and its biomass production was higher. The weight increases in vaconas were favorable to the treatment with F1OO. The animals that pastured the most fertilized pastures with Pollinaza showed better consumption of grass and grassland condition greater weight gains and weights at the end of the test than the animals that grazed the less fertilized with pollinaza.
Relationship between ecuatorian student’s learning styles and academic performance in soil science
(2018) Quichimbo Miguitama, Pablo Geovanny; Aguirre de Juana, Angel Javier; Chérrez Chérrez, Giomara Michelle; Quichimbo Miguitama, Edison Andrés; Vanegas Cabrera, Raul Alejandro; Jiménez Alvarez, Leticia Salomé
nowadays, there has been increasing interest in topics related to education on soil science, however, topics about learning on this science have been poorly studied, particularly the relationship between learning styles and academic performance has not yet been addressed in the literature. this study aimed to understand the different student learning styles of soil science and their effect on their academic performance at the career of agronomy engineering (university of cuenca, ecuador). For this purpose, this case-study research was based on the application of the chaea questionnaire in order to identify and relate the learning styles with the academic scores of a group of ecuadorian students who receive introductory courses on soil science. results demonstrated a general preference of students towards “pragmatic” and “activist” learning styles. in addition, marked differ- ences by gender are clearly noticeable in terms of learning styles, being men more “pragmatic” than women, while women are more “activist” than men. additionally, women revealed a tendency to be more “theoretical” and “reflective” than men. at last, our results suggest that academic performance was not influenced by learning styles. however, in students who showed multimodal preferences of learning styles, their academic performance became higher. these results highlighted the relevance that education plans in soil science need to consider the diversity of students in terms on their learning style preferences.
Shrub encroachment in Mediterranean mountain grasslands: Rate and consequences on plant diversity and forage availability
(2023) Aguirre de Juana, Angel Javier
Question: Shrub encroachment has been confirmed in the past decades all over the world and is currently viewed as a “global process” threatening many grass-dominated biomes. In southern Europe has generally been related to rural depopulation, land-use changes and grazing abandonment. Nevertheless, in several mountain ranges of the Iberian Peninsula with secular pastoralism and high shrub cover, neither stocking rate nor traditional management has substantially altered in the past decades. Within this framework, to deepen our knowledge of shrub encroachment and to adopt, if necessary, appropriate control measures, we aim to discover: (i) the overall expansion rate in the main grassland–shrub communities; (ii) the course of shrub expansion; and (iii) the consequences for grassland floristic composition, plant diversity and frequency of the main forage functional groups throughout the period of woody expansion. Location: This study was undertaken in Moncayo Natural Park (Spain), a climate and vegetation crossroads with remarkable presence of four widespread Mediterranean shrubs: Cytisus oromediterraneus, Erinacea anthyllis, Juniperus communis and J. sabina. Methods: To determine the expansion rates of those shrubs, we examined four distinct and sufficiently separated grazing areas (and different shrub combinations), each with four different stages of shrub cover, over a 6-year period. To assess changes in vegetation structure between 2008 and 2014 during the different stages of shrub encroachment, we used a paired t-test comparing 14 parameters related to the diversity, life-form spectra and abundance of grazing plants. The influence of year, cover category and zone was jointly assessed using a Linear Mixed Model. Results: For the whole territory, we found an increase in average yearly cover of 1.3% (with high variation between the four species), although at the zone scale (areas with a particular shrub dominance) this increase was significant in only half of them. When the four shrubs occur together, Juniperus species show faster expansion rates than the other two species, although in only a few cases was the increase significant over the 6 years of the study. We found a significant decrease in total plant diversity and a significant increase in dominance between cover categories and years. Looking at the vegetation life-forms, the increase in chamaephytes and phanerophytes, which include invader shrubs, caused a decrease in therophytes and hemicryptophytes. Finally, grasses and leguminous plants, which constitute the main livestock food intake, showed noticeable reductions, resulting in loss of pastoral value. Conclusions: Although cessation of grazing has been noted as the main cause of shrub encroachment in Mediterranean grasslands, our results, suggest that encroachment occurs despite the maintenance of stocking rate and livestock management, and leads to a decrease in plant diversity and grassland quality. Focusing on use of the territory and taking into account the prevalence of negative effects after shrub encroachment, additional measures to safeguard ecological and pastoral values in Mediterranean mountain grasslands should be considered, particularly on sites of nature conservation interest with a long grazing history