Revista Alfa

Use of calcium amendments to improve chemical properties and nutrient availability of acidic soils

Mario Humberto Taípe Cancho — 2025-09-10

Existem vários corretivos de cálcio utilizados para corrigir a acidez do solo. The research work was experimental, the objective was to evaluate the effect of dolomite and silicate on chemical properties, nutrient availability in acid soils of Maynas, Iquitos. The methodology was incubation in a laboratory in Cañete. Different doses of amendments were applied: 2.5 t/ha, 5 t/ha and 10 t/ha of dolomite, silicate, with the comparison of the control treatment, with acid soil without amendments. The design used was the Complete Randomized Design (CRD) with three replications, with a total of 21 experimental units. The results of dolomite, silicate presented statistically similar behaviors in the improvement of chemical properties. The increase of pH and C.I.C.E. was observed with the increase of the applied dose, obtained at pH 6.47, with the pplication of 10 t/ha of amendment. Soil acidity decreased significantly, being reduced to 0.11 mEq-g/100 g, with the same dose of calcium amendments. The availability of nutrients, it was evidenced the increase of amendment doses up to 10 t/ha of dolomite and silicate, there was an increase in the concentration of cations: Calcium (up to 1056.10 ppm) and magnesium (up to 254.60 ppm), as in phosphorus, which reached 6.40 ppm. Potassium did not show significant variation with the different doses, maintaining an average of 40.15 ppm in all treatments. The most notable results were obtained with treatments T6 and T7, with higher doses (10 t/ha) of dolomite and silicate.

Photovoltaic energy systems: A systematic review

Russsbelt Yaulilahua-Huacho — 2025-09-10

Photovoltaic solar energy is fundamental to the global energy transition, offering a clean and sustainable source. This systematic review (2019-2025) analyzes the technical optimization, sectoral applications, and energy management of photovoltaic systems. It highlights that adjusting the tilt angle and azimuth, along with solar tracking systems, can increase efficiency by 5% to 40%. Thermal effect mitigation improves performance in hot climates. Applications include agroindustry, rural electrification, electric mobility, and manufacturing, where advanced technologies such as multifunctional inverters and energy storage optimize production and reduce costs and emissions. However, challenges remain in initial costs, maintenance, and adaptation to existing electrical grids. Future research is recommended to focus on accessible, durable technologies and inclusive business models to expand access in vulnerable communities.

Economic valuation of agroforestry systems in Alto Huallaga

José Kalion Guerra Lu — 2025-09-10

The implementation of agroforestry systems has gained relevance in the search for sustainable alternatives for rural development in various regions of Peru. Objective: This research economically evaluated the agroforestry systems implemented by DEVIDA in Alto Huallaga, Leoncio Prado Province, Huánuco. Methodology: A quantitative approach was used with a descriptive-correlational design and a non-probabilistic sample of 20 family farming units distributed across seven districts. Results: The findings determined that the average economic value of the tree component reached S/. 42,715 per hectare, while the agricultural component generated S/. 36,927 per hectare. The comparative analysis revealed that agroforestry systems increase average profitability by 95.4%, rising from 34.7% without agroforestry systems to 67.8% with their inclusion (p<0.001). Conclusion: Agroforestry systems represent a financially viable alternative for sustainable rural development in the Amazon region. Active promotion is recommended through comprehensive training programs and natural resource management.

Mathematical models for urban environmental noise prediction: critical review 2020-2025

Luis Antonio Flores Flores — 2025-09-10

In recent years, the use of predictive models for urban environmental noise has gained relevance as a tool to support sustainable urban management. This systematic review of 50 studies published between 2020 and 2025 reveals significant progress in the development and application of mathematical, statistical and computational models to estimate noise levels in urban environments. The most frequent approaches include multiple linear regression models, geostatistical analysis, artificial neural networks, support vector machines and long short-term memory networks. Integration with Geographic Information Systems and mobile platforms has improved spatial resolution and data accessibility. The most used variables include vehicular volume, building density, meteorological conditions and time of day. The most accurate models achieved determination coefficients greater than R² = 0.90, demonstrating their potential in territorial planning, acoustic zoning and environmental monitoring. Despite these advances, challenges persist such as lack of real-time data, limited community participation and limited application in intermediate cities in Latin America. This review provides a solid foundation for developing predictive tools applicable to contexts such as Iquitos, Peru.

Impact of Lake Chinchaycocha pollution on the right to a healthy environment in Ondores, 2018

Flora Máxima Araujo Reyes — 2025-09-10

Water is essential for life, sustaining health, the ecosystem, and human development. The purpose of this article was to determine the relationship between the pollution of Lake Chinchaycocha and the fundamental right to enjoy a balanced and adequate environment in Ondores, Junín, Peru, in 2018. A non-experimental design, with a correlational scope and a cross-sectional quantitative approach, was used to evaluate 268 residents using a questionnaire as an instrument. The results show that the population perceives high pollution in Lake Chinchaycocha, with concerns about species extinction and sociocultural loss, with women and older adults demonstrating greater environmental sensitivity. Although 41% recognize the right to an adequate environment, there are limitations in its fulfillment. The moderate correlation (0.566) between pollution and violations of environmental rights highlights the need to integrate environmental management with the legal protection of individual and collective rights to safeguard community well-being.

Biological cycle of the “cocona leaf worm” Mechanitis polymnia proceriformis Bryk (Lepidoptera: Ithomyidae) in Pueblo Nuevo, Peru

Zidney Danilo Cristancho Ariza — 2025-09-10

The duration of the biological cycle of Mechanitis polymnia proceriformis Bryk was determined under laboratory conditions in Tingo María, Huánuco. The sample consisted of larvae collected from cocona crops. Eggs measure 1.52 × 0.63 mm with 86.76% viability, 39 eggs per clutch and incubation period of 5.25 days. Larvae present five instars measuring 3.30 × 0.60, 6.20 × 1.00, 10.80 × 1.43, 17.20 × 2.27 and 23.40 × 2.95 mm respectively. The pupa measures 15.92 × 5.95 mm. Adults present wing span of 65.00 mm, longevity of 3.5 days and sex ratio of 1:1.4. The biological cycle lasts 29.65 days. This information is relevant for biological control programs and development of sustainable economic alternatives.

Environmental impact on water in the mine mouths of La Rinconada mining center, Puno

Francisco Fuentes Ruiz — 2025-09-10

La actividad minera a pequeña escala realiza vertimientos de agua de mina sin realizar tratamiento alguno los cuales contienen diferentes metales pesados y son causantes en problemas de la calidad del agua afectando a todo ser vivo generando problemas de conflicto social con las áreas de influencia de la mina. Se planteó como objetivo de la investigación determinar el impacto ambiental hídrico en las bocaminas del centro minero La Rinconada – Puno. La metodología que se aplicó fue un enfoque cuantitativo, tipo de investigación no experimental ya que no se manipuló ninguna variable, el diseño fue descriptivo transversal, se tomó como muestra 500 ml de agua por bocamina de las 03 bocaminas seleccionadas, mediante plasma de acoplamiento inductivo – espectrometría de emisión atómica EPA METHOD 200.7 con tres repeticiones para cada muestra. Los principales resultados fueron que el agua no es apta para ninguna categoría o subcategoría respecto a las ECAs. Concluye que se logró determinar el impacto ambiental hídrico en las 03 bocaminas del centro minero La Rinconada – Puno, siendo un impacto negativo debido a sus altas concentraciones de metales pesados respecto a las ECAs para aguas del Perú, no es apto para la producción de agua potable, recreación, riego de vegetales y bebida de animales.

Chrysomelids associated with a horticultural agroecosystem in Oxapampa, Pasco, Perú

Luis Tibhy Acosta Trinidad — 2025-09-10

In Oxapampa, various species of the Chrysomelidae family are considered agricultural pests, which, given their potential impact on horticultural crops, makes their study essential. In this context, the objective of this research was to identify the chrysomelids associated with the horticultural agroecosystem of the Miraflores III Experimental Field at the Daniel Alcides Carrión National University. To this end, seven surveys were conducted in the horticultural field from May 9 to July 11, 2025. Plant species associated with the family Chrysomelidae were recorded, and the Simpson index was also evaluated to estimate their diversity. Four taxa were found, with the species Epitrix (Alticini) being the most predominant (59.54%), followed by Acalymma (Luperini) (26.78%), Diabrotica (Luperini) (11.56%), and Gynandrobrotica (Luperini) (2.12%), the latter being reported for the first time in the district. The diversity index was 0.56. In conclusion, the Chrysomelidae community associated with horticultural crops in the Miraflores III Experimental Field (Oxapampa) consisted of four taxa, which were linked to 25 plant species.

Relationship among nodule content, cowpea yield and phosphate application

Antonia Elizabeth Medina Paredes — 2025-09-10

Con el objetivo de evaluar el efecto de la fertilización fosfatada sobre conteo de nódulos y rendimiento del grano en frejol (Vigna unguiculata) variedad San Francisco-I, Método: se realizó un experimento en Medina, Ñeembucú, Paraguay. El suelo experimental fue Entisol (Typic Psammaquent), con baja fertilidad y bajo contenido de fósforo. Se utilizó un diseño de bloques completamente al azar con cuatro repeticiones y cinco niveles de fertilización fosfatada (0, 25, 50, 100 y 200 kg P₂O₅/ha). A los 60 días se evaluó el conteo de nódulos por planta y al momento de cosecha se midió el rendimiento de grano. Los resultados mostraron diferencias significativas (p<0,05) en conteo de nódulos y diferencias altamente significativas (p<0,01) en rendimiento de grano según niveles de fosfato aplicados, observándose relación positiva entre nodulación y productividad. Conclusiones: El tratamiento con 50 kg P₂O₅/ha presentó el mayor beneficio económico, considerándose la dosis óptima para condiciones de baja fertilidad.

Water pollution and environmental right in Lircay, Huancavelica

Johel Cárdenas Solano — 2025-09-10

The study determined the relationship between water pollution and the fundamental right to a healthy environment in Lircay, Huancavelica, 2024. With a sample of 268 residents and applying Spearman’s correlation coefficient, ρ = 0.74 (p = 0.001) was obtained, evidencing a high and significant positive correlation. Greater perception of pollution corresponds to greater violation of environmental rights. The dimensions of fundamental rights showed significant correlations: human dignity (ρ = 0.68), diffuse belonging interest (ρ = 0.54), and finalist and personalist right (ρ = 0.44). The findings confirm that water pollution transcends the ecological sphere, directly affecting fundamental human rights. Public policies are required that articulate environmental management with rights protection, incorporating remediation measures, environmental monitoring, and citizen participation.

Simple hybrids of opaque corn (Zea mays L.) with high protein content for guinea pigs

Edgardo Arturo Vilcara Cárdenas — 2025-09-10

Ninety-eight single hybrids of forage corn and two parental controls (Opaco and Dekalb) were evaluated using a 10 x 10 simple lattice design to identify superior genotypes in protein content for guinea pig feeding. The 36 best hybrids selected for forage aptitude were analyzed to determine protein content and heterosis. Single hybrids 9 and 89 achieved protein contents of 11.7% and 9.9% respectively, surpassing the controls Opaco (9.7%) and Dekalb (8.9%). Heterosis allowed increases of up to 2% and 2.8% compared to parents. 5.56% of hybrids surpassed both controls in protein content, demonstrating the potential of hybrid vigor to improve nutritional quality of forage for guinea pig breeding

Effect of Azospirillum brasilense on carbon capture and maize yield

Marino Bautista Vargas — 2025-09-10

Carbon dioxide is one of the main gases responsible for climate change. This study evaluated the effect of Azospirillum brasilense inoculation on carbon sequestration and Zea mays yield under field conditions in Acobamba-Huancavelica. A randomized complete block design with four treatments (0, 16, 32, and 64 g of A. brasilense per kg of seed) and four replications in different environments was applied. Statistically significant differences (p<0.05) were observed in carbon weight, height, dry weight, fresh weight, and grain yield. Inoculation with 64 g of A. brasilense per kg of seed increased carbon sequestration by 8.15% and grain yield by 28.12%. These results demonstrate the affinity between maize and this plant growth-promoting bacterium and its potential as a sustainable alternative to mitigate climate change.