Homar Santillan Gomez

This study evaluated the effect of forced-air solar drying and biogas-assisted hybrid solar drying on the overall quality of dehydrated Andean berries. Blueberry (Vaccinium corymbosum) and goldenberry (Physalis peruviana) were analyzed before and after dehydration using two systems: forced-air solar drying (DCFA) and biogas-assisted hybrid solar drying (DCFA-BG). Physicochemical properties, instrumental color, texture, rehydration index, total phenolic content, total flavonoid content, and antioxidant capacity were determined. Drying markedly reduced moisture content and water activity in both fruits. In blueberry, DCFA-BG achieved the lowest moisture content (22.00%) and water activity (0.65), whereas goldenberry showed similar final moisture contents under both systems, with lower water activity under DCFA-BG (0.64). Total soluble solids and titratable acidity increased after drying, indicating solute concentration. Color changes were more pronounced in goldenberry, while blueberry showed moderate chromatic variation. Blueberry firmness increased after drying, whereas goldenberry exhibited treatment-dependent textural responses. Blueberry showed greater retention of bioactive properties, with increased antioxidant capacity after drying, whereas goldenberry exhibited substantial reductions in phenolic content, flavonoid content, and antioxidant capacity. Overall, biogas-assisted hybrid solar drying effectively reduced moisture content and water activity, although its effects on product quality depended on the fruit matrix. These findings support its potential application as a sustainable alternative for processing perishable fruits in high-Andean rural agroindustrial contexts.

The intensive use of synthetic fertilizers in horticultural systems has raised environmental and economic concerns, prompting the search for sustainable alternatives for nutrient management. Liquid digestates derived from the anaerobic digestion of animal manure represent a promising option within circular economy frameworks. This study evaluated the growth and yield response of romaine lettuce ( Lactuca sativa L. var. longifolia ) to liquid digestates derived from guinea pig, pig, and cattle manure in northeastern Peru. A completely randomized design with a factorial arrangement was used, considering digestate type, application dose (2%, 4%, and 6% v/v), and application frequency (every 7 and 10 days). Growth and yield traits, including plant height, collar diameter, fresh weight, and number of leaves, were evaluated at commercial maturity. Significant differences among treatments were observed for all evaluated variables. The highest overall agronomic response was obtained with pig-manure digestate applied at 6% every 10 days (T12), reaching 28.00 ± 1.01 cm in plant height, 3.45 ± 0.35 cm in collar diameter, 790.83 ± 77.51 g of fresh weight per plant, and 51.08 ± 1.62 leaves per plant. Application frequency had a limited effect, although the 10-day interval produced the best overall response when combined with pig-manure digestate at the highest dose. These results indicate that liquid digestates, particularly pig-manure digestate, may serve as a promising alternative nutrient source for romaine lettuce grown under alkaline highland greenhouse conditions.

Agrivoltaic systems offer a pathway to simultaneously produce food and electricity, yet their effectiveness depends on how photovoltaic configurations influence crop productivity under specific environmental conditions. This study evaluated land-use efficiency in an Andean–Amazon transition region using monofacial, bifacial, and semitransparent photovoltaic configurations integrated with a maize–bean intercrop. Land-use efficiency was quantified through the Land Equivalent Ratio (LER), combining agricultural yield and electrical energy production. All configurations achieved LER values above 1.0, confirming a clear advantage over separate land use. The semitransparent configuration showed the highest LER (1.95–1.99), followed by bifacial (1.66–1.90) and monofacial systems (1.51–1.72). LER variation was driven primarily by crop productivity rather than energy yield, while normalized photovoltaic performance remained stable across configurations. These results demonstrate that agrivoltaic performance is governed by system-level crop response, emphasizing the role of photovoltaic design in optimizing food–energy systems under tropical mountain conditions.

This study experimentally evaluates the thermal performance of a compact parabolic trough solar collector (PTSC) operating under actual solar conditions in Chachapoyas, a high-Andean city in northern Peru characterized by frequent cloud cover and variable irradiance. Despite the growing interest in solar thermal systems, few studies have assessed PTC behavior under high-altitude, diffuse radiation conditions typical of Andean regions. The PTSC, aligned along the north–south axis and equipped with a manual solar tracking system, was monitored for 30 consecutive days. Solar irradiance, ambient temperature, and water inlet/outlet temperatures were recorded at 30 min intervals using a DAVIS Vantage Pro Plus weather station and infrared thermometers (±0.5 °C accuracy). Thermal efficiency was determined from the ratio of useful heat gain to incident solar energy, based on instantaneous irradiance data. Results showed peak irradiance values of 1000 W m⁻² and maximum outlet water temperatures of 85 °C, achieving an average efficiency of 68 ± 2.5%. The collector maintained stable operation even under fluctuating radiation, confirming its suitability for domestic hot-water and low-temperature industrial applications. These findings provide the first experimental evidence of efficient solar-thermal conversion in cloudy highland environments of Peru, supporting the deployment of decentralized renewable energy systems in the Andean region.

La transición hacia energías limpias demanda el uso de tecnologías emergentes como los paneles solares semitransparentes (TSPV); sin embargo, existe una brecha de investigación sobre su desempeño real en entornos tropicales de altura como Chachapoyas que está a 2232,46 m.s.n.m, caracterizados por alta nubosidad y humedad. La hipótesis formulada fue que el rendimiento energético del panel TSPV está determinada por su interacción directa con las condiciones climáticas predominantes (radiación, temperatura, humedad y viento) de la ciudad de Chachapoyas. En el material de estudio, se utilizó un panel solar semitransparente de 130 W (modelo I-ESF-M-M156-24-130W) con un área de campo solar de 0,592 m2. El método utilizado para la investigación fue no experimental, cuantitativa y longitudinal de cuatro meses (agosto-noviembre 2025) basada en la Norma UNE-EN-IEC 61724-1. Se empleó una estación meteorológica Davis Vantage Pro2, un piranómetro EKO MS-711 y dataloggers Arduino para realizar mediciones cada 5 min. Se registró un promedio de 3,24 HSP y un rendimiento final (YF) de 2,99 h. El sistema alcanzó un factor de rendimiento (PR) de 92,22 %, indicando un alto desempeño operativo. Las pérdidas externas (suciedad o temperatura) fueron mínimas (1,05 %), mientras que las pérdidas del sistema por la ineficiencia del inversor fueron del 6,73 %. El sistema opera con alto rendimiento en Chachapoyas. El alto PR confirma que las pérdidas de captura son insignificantes, identificándose la conversión DC/AC del inversor como la principal limitante técnica. El diseño de la instalación logró maximizar la captación del recurso solar disponible.

This study evaluates the thermal performance of a prototype vacuum-tube solar cooker adapted to the climatic conditions of the Amazon region, Peru. Four grain types (Zea mays L., Triticum aestivum, Zea mays var. morochon, and Hordeum vulgare) were tested to assess temperature evolution, exposure time, and incident solar radiation. Hordeum vulgare was selected as a food model for calibration due to its well-characterized thermophysical properties and reproducible heating behavior. The results showed individual thermal efficiencies ranging from 19.3% to 35.3%, with an average of 27.3% across the three tubes. The most efficient treatment, obtained with Zea mays L., reached 180 °C under an irradiance of approximately 980 W/m². A direct relationship was observed between solar radiation intensity, exposure time, and thermal efficiency. These findings confirm that the proposed hybrid design combining a cylindrical parabolic collector with vacuum U-tubes achieves higher and more stable performance than conventional box-type cookers. The system allows complete grain cooking without fossil fuels, demonstrating its potential as a sustainable and low-cost solution for rural communities in the Andean Amazonian region, promoting clean energy adoption and reducing environmental impact.

This study evaluated the physicochemical and microbiological characteristics of digestate produced by anaerobic digestion of bovine rumen content at the Chachapoyas Municipal Slaughterhouse (Peru) to determine its potential as a biofertilizer. Key effluent quality parameters, pH, turbidity, total solids, dissolved oxygen, nutrients, metals, and microbial indicators, were analyzed following Standard Methods for the Examination of Water and Wastewater. Results showed a substantial improvement in the physicochemical quality of the digestate, evidenced by a sharp reduction in turbidity (6620 to 770 NTU) and total solids (31.645 to 2.797 mg L⁻¹), along with an increase in dissolved oxygen (0.18 to 2.19 mg L⁻¹) and a near-neutral pH (6.74–6.86). Nitrites, sulfates, aluminum, iron, and barium concentrations decreased markedly, while potassium and magnesium increased, reinforcing the digestate’s agronomic potential as a nutrient-rich biofertilizer. Conversely, the microbiological analysis revealed persistent contamination by total and fecal coliforms, as well as Escherichia coli (1.52 × 10⁶ MPN/100 mL), although Salmonella spp. and Vibrio cholerae were not detected. These findings indicate that while anaerobic digestion enhances the physicochemical stability and nutrient composition of the digestate, it does not ensure microbiological safety. Post-digestion treatments such as composting, pasteurization, or biochar adsorption are recommended to guarantee safe agricultural application within sustainable production systems.

This study evaluated the intercropping of forage maize (Zea mays L.) and common bean (Phaseolus vulgaris) varieties in the Amazon region of Peru, with the objective of identifying combinations that optimize agricultural yield. A factorial design with 11 treatments was applied, combining three maize varieties (Chuska INIA, Marginal 28T, and Advanta) and two bean varieties (Vidillo and Wasca). The results showed that the combination of Chuska INIA maize and Vidillo bean (T1) achieved the best performance in terms of plant height (252.13 ± 3.33 cm) and number of leaves (14.08 ± 0.14), indicating a favorable interaction between these varieties. In contrast, combinations involving Advanta maize exhibited lower values for these parameters, suggesting limited adaptation to intercropping. Leaf length and width did not differ significantly among treatments, indicating that these traits are less sensitive to crop combinations. Regarding forage yield, the T1 treatment stood out with the highest values for fresh forage and dry matter yield, demonstrating the potential of this association to enhance productivity. These findings highlight the importance of selecting crop combinations that maximize production while promoting sustainability and efficiency in the region’s agricultural systems. It is concluded that intercropping Chuska INIA maize with Vidillo beans is a promising alternative for increasing forage yield in the Peruvian Amazon, contributing to agricultural sustainability by reducing input use and improving soil health.

The increasing demand for food and energy presents challenges for agricultural and energy sustainability, especially in regions with limited arable land. This study analyzed the productivity and morphological adaptations of Phaseolus vulgaris L. in agrivoltaic systems using monofacial, bifacial, and semi-transparent photovoltaic technologies under the high Andean climatic conditions of Chachapoyas, Amazonas, Peru. The evaluated varieties, Panamito and Chaucha, were cultivated with planting distances of 25 cm and 35 cm. The analyzed variables included plant height, number of trifoliate leaves, number of flowers, number and weight of pods, grain weight, and yield. The experiment was designed with plots under agrivoltaic systems and a conventional system as a control. Environmental parameters such as photosynthetically active radiation (PAR), irradiance, precipitation, leaf moisture, soil moisture, and ambient temperature were monitored. Results showed that the bifacial system with a planting density of 25 cm was the most efficient, recording a plant height of 139.38 cm, an average grain weight of 67.97 g, and a yield of 700.5 kg/ha, significantly surpassing the conventional system. These findings shows the potential of agrivoltaic systems to enhance agricultural production by efficiently utilizing solar radiation and land, providing an innovative solution for integrating agriculture and energy generation, as well as increasing productivity in scenarios with land-use competition and climatic challenges.

This study evaluated the germination of Cinchona spp. seeds under controlled environmental conditions within a geodesic dome equipped with photovoltaic energy. The main objective was to assess how stable temperature and humidity, along with potassium nitrate (KNO₃) and specific LED light treatments, affect the germination rate and plant growth. The results indicate that Cinchona spp. seeds germinate effectively inside the dome, even under temperature and humidity conditions that differ from their natural habitat. Among the evaluated conditions, the treatment with 1000 ppm of KNO₃ and white LED light (LM 1000 ppm) showed the highest germination rate, achieving 72.5% with an average of 1.5 seeds germinated per day. Agronomic evaluations showed that this treatment also led to superior growth metrics, including an average plant height of 2.1 cm, an average leaf count of 3.6, and a dry weight of 0.0013 g. This research highlights the potential of controlled environments, such as geodesic domes, to optimize germination and early growth in endangered plant species. The combination of environmental control with KNO₃ treatments offers a valuable approach to enhancing the propagation of Cinchona spp., providing practical implications for conservation and reforestation efforts. This work provides a foundation for further studies on optimizing germination and growth conditions for other native and endangered species in controlled environments.