En esta unidad se explica qué es el sistema de riego por aspersión, cuál es su funcionalidad y cómo se debe realizar la instalación del equipo de riego.

Abtract: Small-scale farming systems in the Colombian Andes are vulnerable to threats that affect not only the food production and self-sufficiency of local communities, but that can affect the wellbeing of farmers and the environment. A holistic perspective of agriculture leads to understanding of the complexity of agroecosystems including its elements, processes, dynamics, interactions, synergies and trade-offs. This thesis examines the main characteristics, contexts and enabling environment for small-scale farming systems in Guachetá, Colombia, in order to identify and analyse the main agricultural problems in the municipality and possible solutions for them. Using the Tool for Agroecology Performance Evaluation (TAPE), the 10 elements of agroecology were evaluated on 7 farms along with the assessment of the performance of the systems using core performance criteria based on 5 key dimensions of sustainability. Furthermore, the analysis of qualitative data obtained from interviews with farmers and other actors, such as associations’representatives and academics in the fields of soils and agricultural science, facilitated the understanding of their perspectives in relation to the challenges that peasant farmers face. The results of this study show that the prevalence of dry climatic conditions and the variation on the typical rain patterns pose a major challenge for the current production system. In addition, the enabling environment, in regards to responsible governance and circular and solidarity economy, constitutes one of the major limitations. Currently, there are negligible possibilities for participation on the governance of the land and there is limited access to markets that offer fair conditions and proximity between consumers and producers. Also, the current agricultural practices reflect dependency on agrochemical inputs that, according to the analysis of the elements of agroecology, leads to low efficiency of the systems, limited agricultural biodiversity and low synergies within the agroecosystems. It is concluded that implementation of agroecological principles and practices that resemble natural ecological processes and that are characterized by joint action can aid in overcoming these issues leading to the improvement of the sustainability of food systems in Guachetá.

Abstract: The use of bacterial pigments with biotechnological potential advances are growing and more and from this natural source are developed several products with different applications in the pharmaceutical, food, cosmetics and other industries, presenting advantages in economic and environmental issues, fulfilling a demand and bringing benefits For consumer health and reducing the use of chemical synthetized products. The aim of this study was the production, working volume and characterization of pigments synthesized by Chryseobacterium KR6 and Lysobacter A03 bacteria isolated from chicken and penguin feathers, respectively. The pigments were characterized by KOH 20% test, UV-visible, colors system CIELAB, HPLC-DAD-MS, FTIR and was evaluated the antioxidant capacity. The pigments from KR6 and A03 presents some characteristics from flexirubin and xanthomonadin non- brominated type pigments respectively. Pigment from KR6 shows a positive bathochromic shift when colonies or the extracted pigment are in presence of alkaline solution (KOH20%) and also have a λmax at 450nm in acetone when analyzed by UV-Vis. The FTIR analysis shows some principal functional groups that might be from a flexirubin molecule. Pigment from A03 didn’t present any shift when flooded with KOH and the λmax was 419 nm and 427 nm in acetone and chloroform respectively. The two pigments presented antioxidant activity evaluated by the capture of the free radical ABTS. It was not possible to propose a chemical structure for the two pigments; purification processes are necessary for a molecular identification of the biotechnologically viable pigments.

Resumen: En las últimas décadas en Colombia se han percibido cambios importantes en la agricultura, relacionados con la concentración de la tierra, la expansión de la frontera agropecuaria, el crecimiento de algunos cultivos propios de la agricultura empresarial, así como el interés y adquisición de tierras por parte de actores nacionales y extranjeros. A nivel de las políticas públicas, los últimos gobiernos han realizado esfuerzos por permitir, en la legislación, la adquisición o el uso de tierras públicas por parte de empresas. Se destaca, dentro de estos esfuerzos, la promulgación de la Ley Zidres en 2016. Dichas transformaciones se enmarcan dentro de dinámicas internacionales que han llevado a la adopción del modelo de agronegocio en diferentes países. Esta tesis analiza, en el marco del neoliberalismo, la expansión del agronegocio en Colombia, a través del estudio de las transformaciones a nivel productivo, territorial y de las políticas públicas. El desarrollo de esta investigación se apoyó en la discusión teórica sobre hegemonía, en los elementos del análisis del discurso y en los desarrollos conceptuales sobre el agronegocio. El recorrido histórico sobre la cuestión agraria en Colombia, así como el estudio de la implementación del neoliberalismo y los cambios generados en la agricultura, que se han profundizado en los últimos años, sugieren la disputa del agronegocio por la hegemonía. Esta se ha intensificado, principalmente, a partir del acuerdo de paz firmado entre el gobierno de Juan Manuel Santos y la guerrilla de las FARC-EP, que incluyó la pauta de la Reforma Rural Integral y dio protagonismo a la economía campesina y a la democratización de la tierra.

Abstract: The use of phytoextraction plant species to accumulate soil metals into harvestable plant parts is a method used for managing soils with high cadmium (Cd). We evaluated three Cd accumulating species recently recommended for such use in cacao farms where Cd removal is needed to maintain markets: Helianthus annuus (sunflower), Brassica napus (rapeseed), and Chyrsopogon zizanioides (vetiver). Plants were grown in two greenhouse pot experiments with different Cd-spiked growth media: (sand plus perlite) and a natural soil. Plant total Cd and Cd uptake in shoot biomass of all species, across both experiments, increased linearly with increasing amounts of added Cd. Rapeseed had the highest plant total Cd and sunflower had the highest Cd uptake in shoot biomass. The highest application of Cd corresponded to the highest plant total Cd and shoot biomass Cd uptake, regardless of species. The bioconcentration factor (BCF) for each species increased in a curvilinear manner with added Cd, with maximum BCF values for plants grown in the sand and perlite matrix at 2.5 mg kg-1 added Cd and in the natural soil at 5.0 mg kg-1 added Cd. We conclude that the Cd uptake (shoot biomass only) capability of the three species examined is greatest for sunflower given its increased uptake with Cd additions, its BCF value > 1, and lack of observed visual Cd toxicity symptoms, fungus and insect damage. Although these species had BCF >1, the potential annual removal of Cd would have been too small to support a meaningful phytoextraction practice. Resumen: El uso de especies de plantas de fitoextracción para acumular metales del suelo en partes de plantas cosechables es un método utilizado para manejar suelos con alto contenido de cadmio (Cd). Evaluamos tres especies acumuladoras de Cd recomendadas recientemente para tal uso en fincas de cacao donde se necesita remoción de Cd para mantener los mercados: Helianthus annuus (girasol), Brassica napus (colza) y Chyrsopogon zizanioides (vetiver). Las plantas se cultivaron en dos experimentos en macetas de invernadero con diferentes medios de crecimiento enriquecidos con Cd: (arena más perlita) y un suelo natural. La absorción total de Cd y Cd de la planta en la biomasa de brotes de todas las especies, en ambos experimentos, aumentó linealmente con cantidades crecientes de Cd agregado. La colza tuvo el mayor Cd total de la planta y el girasol tuvo la mayor absorción de Cd en la biomasa de los brotes. La mayor aplicación de Cd correspondió a la mayor absorción de Cd total de la planta y de la biomasa de brotes, independientemente de la especie. El factor de bioconcentración (FBC) para cada especie aumentó de manera curvilínea con Cd agregado, con valores máximos de FBC para plantas cultivadas en la matriz de arena y perlita a 2.5 mg kg-1 de Cd agregado y en el suelo natural a 5.0 mg kg-1 añadido Cd. Concluimos que la capacidad de absorción de Cd (solo biomasa de brotes) de las tres especies examinadas es mayor para el girasol debido a su mayor absorción con adiciones de Cd, su valor de FBC> 1 y la falta de síntomas de toxicidad visual de Cd, hongos e insectos observados. Aunque estas especies tenían FBC> 1, la posible eliminación anual de Cd habría sido demasiado pequeña para sustentar una práctica de fitoextracción significativa.

Abstract: Pigments synthesised by Chryseobacterium sp. kr6 growing on feather waste were extracted and characterised. The pigment extract was characterised by KOH test, UV–vis, CIELAB colour system, HPLCDAD- MS, FTIR and its antioxidant capacity was evaluated. A positive bathochromic shift was observed when kr6 colonies or pigment extracts were subjected to alkaline solution (20% KOH) and a λmax at 450 nm was detected for acetone extracts, although no typical fine structure of carotenoids was detected in the electomagnetic spectra. The HPLC profile of the extracted pigment showed that the compound has three different peaks with λmax near 450 nm. The FTIR analysis shows some principal functional groups from a flexirubinlike molecule. The pigmented compound also presents antioxidant activity evaluated by the scavenging of the ABTS radical.

Abstract: The world demands new solutions and products to be used as dyes for industrial applications. Microbial pigments represent an eco-friendly alternative as they can be produced in large amounts through biotechnological processes and do not present environmental risks, as they are easily decomposable. Moreover, some of these metabolites are recognized for their biological activities, which qualify them for potential uses as food colorants and nutraceuticals, protecting against degenerative diseases related with oxidative stress. Because of their genetic simplicity as compared with plants, microorganisms may be a better source to understand biosynthetic mechanisms and to be engineered for producing high pigment yields. Despite the origin of the pigmented microorganism,it seems very important to develop protocols using organic industrial residues and agricultural byproducts as substrates for pigment production and fi nd novel green strategies for rapid pigment extraction. This review looks for the most recent studies that describe microbial pigments from microalgae, fungi, and bacteria. In particular, the underexploited tools of omics science such as proteomics and metabolomics are addressed. The use of techniques involving mass spectrometry, allows to identify different protein and metabolite profi les that may be associated with a variety of biotechnologically-relevant pathways of pigment synthesis.

Abstract: The use of computer vision, deep learning, and drones has revolutionized agriculture by enabling efficient crop monitoring and disease detection. Still, many challenges need to be overcome due to the vast diversity of plant species and their unique regional characteristics. Olive trees, which have been cultivated for thousands of years, present a particularly complex case for leaf-based disease diagnosis as disease symptoms can vary widely, both between different plant variations and even within individual leaves on the same plant. This complexity, coupled with the susceptibility of olive groves to various pathogens, including bacterial blight, olive knot, aculus olearius, and olive peacock spot, has hindered the development of effective disease detection algorithms. To address this challenge, we have devised a novel approach that combines deep learning techniques, leveraging convolutional neural networks, vision transformers, and cloud computing-based models. Aiming to detect and classify olive tree diseases the experimental results of our study have been highly promising, demonstrating the effectiveness of the combined transformer and cloud-based machine learning models, achieving an impressive accuracy of approximately 99.6% for multiclass classification cases including healthy, aculus olearius, and peacock spot infected leaves. These results highlight the potential of deep learning models in tackling the complex-ities of olive leaf disease detection and the need for further research in the field. Resumen: El uso de visión por computadora, aprendizaje profundo y drones ha revolucionado la agricultura al permitir un monitoreo eficiente de cultivos y la detección de enfermedades. Sin embargo, aún existen muchos desafíos debido a la vasta diversidad de especies vegetales y sus características regionales únicas. Los olivos, que han sido cultivados durante miles de años, presentan un caso especialmente complejo para el diagnóstico de enfermedades basado en las hojas, ya que los síntomas pueden variar ampliamente, tanto entre diferentes variaciones de plantas como incluso dentro de hojas individuales en la misma planta. Esta complejidad, junto con la susceptibilidad de los olivares a varios patógenos, como la bacteriosis, el nudo del olivo, el aculo olearius y la mancha de pavo real del olivo, ha dificultado el desarrollo de algoritmos efectivos de detección de enfermedades. Para abordar este desafío, hemos ideado un enfoque novedoso que combina técnicas de aprendizaje profundo, aprovechando redes neuronales convolucionales, transformadores de visión y modelos basados en computación en la nube. Con el objetivo de detectar y clasificar enfermedades de los olivos, los resultados experimentales de nuestro estudio han sido muy prometedores, demostrando la efectividad de los modelos combinados de transformadores y aprendizaje automático basado en la nube, logrando una impresionante precisión de aproximadamente el 99.6% para casos de clasificación multiclase, que incluyen hojas sanas, infectadas con aculo olearius y mancha de pavo real. Estos resultados destacan el potencial de los modelos de aprendizaje profundo para abordar las complejidades de la detección de enfermedades en las hojas de olivo y la necesidad de más investigaciones en este campo.

Abstract: The egg weight (EW) increases as the hen ages, but unfortunately, eggshell quality does not improve with increasing EW. Dietary changes can help control the increase EW, resulting in improved eggshell quality. This experiment aimed to deterMomine the effect of different digestive lysine (dLYS) levels on the production performance and eggshell quality of 82-87-week-old Lohmann Brown hens and identify the optimal level of dLYS intake to achieve an optimal production performance and the level of dLYS that can improve eggshell quality by modifying EW. A total of 240 Lohmann Brown hens were selected for the experiment (79-87 weeks). These were distributed in individual cages and 6 treatments with 40 replicates per treatment. The cages were divided into 40 blocks of 6 consecutive cages. In each block, the treatments were randomly distributed in the room. The treatments were 6 different diets with different dLYS levels (6.72, 6.40 (control diet (CON)), 6.08, 5.76, 5.44, 5.12 g/kg). The production performance and eggshell quality were evaluated, and the ideal dLYS was calculated by linear broken-line regression. Modifying dLYS levels from 6.08 to 5.12 g/kg decreased a hen day egg production (HDEP) by 4.4%, and reduced egg mass (EM) by 3.2 g/d. Adjusting dLYS levels from 5.44 to 5.12 g/kg reduced 2.2 g the egg weight (EW). Changing dLYS levels from 6.40 to 5.44 g/kg increased the average feed daily intake (ADFI) by 5 g. The different dLYS levels did not affect the feed conversion ratio (FCR), but it showed a tendency (P = 0.074). Eggshell quality attributes were not affected by different dLYS levels. The optimal dLYS intake requirement was 713, 646, 626, and 627 mg/b/d to achieve an optimal HDEP, EW, EM, and FCR respectively. In conclusion, the results of this experiment can help the laying hen industry to determine the optimal dLYS for managing EW increase, keeping a good HDEP, EM, FCR, and maintaining eggshell quality in long-life laying hens.

Abstract: Metarhizium brunneum is a soil-borne fungal entomopathogen that can associate with plant roots. Previous studies have demonstrated that root colonization by beneficial fungi can directly affect soilborne pathogens through competition and antibiosis, and can activate a systemic response in plants, resulting in a primed state for a faster and/or stronger response to stressors. However, the mechanisms by which Metarhizium inoculation ameliorates symptoms caused by plant pathogens are not well known. This study evaluated the ability of M. brunneum to protect oilseed rape (Brassica napus L.) plants against the soil-borne pathogen Verticillium longisporum, and investigated whether the observed effects are a result of direct interaction and/or plant-mediated effects. In vitro and greenhouse experiments were conducted to measure fungal colonization of the rhizosphere and plant tissues, and targeted gene expression analysis was used to evaluate the plant response. The results show that M. brunneum delayed pathogen colonization of plant root tissues, resulting in decreased disease symptoms. Direct competition and antibiosis were found to be part of the mechanisms, as M. brunneum growth was stimulated by the pathogen and inhibited the in vitro growth of V. longisporum. Additionally, M. brunneum changed the plant response to the pathogen by locally activating key defence hormones in the salicylic acid (SA) and abscisic acid (ABA) pathways. Using a split-root setup, it was demonstrated that there is a plant-mediated effect, as improved plant growth and decreased disease symptoms were observed when M. brunneum was in the systemic compartment. Moreover, a stronger systemic induction of the gene PR1 suggested a priming effect, involving the SA pathway. Overall, this study sheds light on the mechanisms underlying the protective effects of M. brunneum against soil-borne pathogens in oilseed rape plants, highlighting the potential of this fungal entomopathogen as a biocontrol agent in sustainable agriculture Metarhizium brunneum es un hongo entomopatógeno del suelo que puede asociarse con las raíces de las plantas. Resumen: Estudios previos han demostrado que la colonización de raíces por hongos beneficiosos puede afectar a patógenos del suelo a través de la competencia, antibiosis, y activar respuesta sistémica en las plants. Sin embargo, los mecanismos por los cuales este hongo atenúa los síntomas causados por fitopatógenos no son bien conocidos. Este estudio evaluó la capacidad de M. brunneum para proteger las plantas de colza (Brassica napus L.) contra Verticillium longisporum, e investigó si los efectos observados son el resultado de una interacción directa y/o efectos mediados por la planta. Se realizaron experimentos in vitro y en invernadero para medir la colonización fúngica de la rizosfera y los tejidos de la planta, y se midió la expresión de genes específicos relacionados con la respuesta de la planta a patógenos. Los resultados muestran que M. brunneum retrasó la colonización del patógeno en las raíces de la planta, y disminuyo los síntomas de la enfermedad. La competencia directa y la antibiosis son parte de los mecanismos, ya que el crecimiento de M. brunneum fue estimulado por el patógeno e inhibió el crecimiento in vitro de V. longisporum. Además, M. brunneum cambió la respuesta de la planta hacia el patógeno al activar localmente genes de defensa mediadas por el ácido salicílico (SA) y del ácido abscísico. Mediante un experimento de raíces divididas, se demostró que existe un efecto mediado por la planta, ya que se observó un mejor crecimiento de la planta y una disminución de los síntomas de la enfermedad cuando M. brunneum estaba en el compartimento sistémico. Además, una mayor inducción sistémica del gen PR1 sugirió un efecto de ""priming"", mediado por SA.