Examinando por Autor "Romero Chávez, Lorena Estefani"

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Climate, carbon, and soil stability: a key link in coffee-growing landscapes of the Peruvian Amazon
(Frontiers Media S.A., 2026-04-14) Romero Chávez, Lorena Estefani; Hermoza Ayme, Nilton Alexander; Chuchon Remon, Rodolfo Juan; Aldava Pardave, Uriel; Arroyo Isuiza, Rosa Karen; Solórzano Acosta, Richard Andi; Vallejos Torres, Geomar
Introduction: Coffee cultivation in the Central Peruvian Amazon, one of the country's most important production regions, faces increasing challenges from soil degradation and climate change impacts. This study aimed to evaluate the influence of the altitudinal gradient on soil organic carbon (SOC) stocks and soil erodibility (K index) in coffee-growing systems. Methods: Three altitudinal zones were established for sampling (0–20 cm depth): zone 1 (900–1200 m.a.s.l.), zone 2 (1201–1400 m.a.s.l.), and zone 3 (1401–1600 m.a.s.l.). Within these zones, physical and chemical soil properties were analyzed, and SOC and soil erodibility (K index) values were calculated. Results: The results revealed a direct and statistically significant relationship between altitude and carbon sequestration capacity. Zone 3 exhibited the highest SOC (63.19 t·ha⁻¹) and organic matter (OM) content (5.49%), compared with zone 1 (37.56 t·ha⁻¹). This difference is attributable to the climatic conditions at higher elevations, characterized by greater precipitation and lower temperatures. Structural equation modeling (SEM) indicated that increasing altitude enhances SOC (b = 0.42), which in turn improves the soil structural stability index (SI) (R² = 0.87) and reduces the K index (b = –0.38). Overall, the findings demonstrate that organic carbon acts as a key mediator between topography, soil texture, and susceptibility to erosion. The altitudinal gradient thus represents a major controlling factor influencing the health and structural stability of coffee soils. Discussion: These results highlight the need to implement site-specific soil management practices, emphasizing intensive conservation strategies in low-altitude coffee-growing systems to mitigate accelerated erosion and ensure long-term production sustainability under changing climatic conditions.
Native entomopathogenic nematodes from Peru control Spodoptera frugiperda, a major pest of Zea mays in the Peruvian Amazon
(MDPI, 2026-03-09) Fachin Ruiz, Grecia; Córdova Sinarahua, Deyvis; Romero Chávez, Lorena Estefani; Alvarado Ramírez, Jaime; Quesquen Lopez, Cesar; Flores García, Eybis; Koch Duarte, Christian; Cerna Mendoza , Agustín; Vásquez Bardales, Joel; Corazon Guivin, Mike
This study evaluated entomopathogenic nematodes (EPNs) isolated from a cacao agroforestry system in the Peruvian Amazon, focusing on their molecular characterization and efficacy against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae. Thirteen EPN isolates were obtained from 50 soil samples using the Galleria mellonella baiting technique. Mortality assays revealed significant differences among isolates at 24, 48, and 72 h, with isolates 11N-A4 and 8N-B1 being the most virulent, achieving maximum mortalities of 100% and 96.3% at 72 h, respectively. Median lethal time (LT50) values indicated rapid action of these isolates on G. mellonella larvae, with 33.3 h for 11N-A4 and 32.4 h for 8N-B1. Molecular identification using ITS, D2-D3 (LSU), and COI markers confirmed the isolates as Heterorhabditis sp. (11N-A4) and Heterorhabditis amazonensis (8N-B1). In bioassays with S. frugiperda larvae, both EPNs exhibited dose- and time-dependent mortality. H. amazonensis showed rapid action, reaching 100% mortality at the highest dose (60 IJs/larvae) within 48 h, whereas Heterorhabditis sp. displayed a gradual, sustained increase, attaining 91% mortality at 72 h. Median lethal dose (LD50) and LT50 values reflected the efficiency of both isolates, with Heterorhabditis sp. achieving lower LD50 at later stages and shorter LT50 at low-to-intermediate doses. These findings highlight the potential of Heterorhabditis sp. and H. amazonensis as effective biocontrol agents adapted to local conditions and represent the first report of H. amazonensis in Peru. Further studies under field conditions are required to confirm their suitability for incorporation into integrated pest management strategies in the Peruvian Amazon.
Spatial analysis of soil acidity and available phosphorus in coffee-growing areas of Pichanaqui: Implications for liming and site-specific fertilization
(MDPI, 2025-07-28) Quispe Matos, Kenyi Rolando; Hermoza Ayme, Nilton Alexander; Mejia Maita, Sharon Yahaira; Romero Chávez, Lorena Estefani; Ottos Díaz, Elvis; Arce, Andrés; Solórzano Acosta, Richard
Soil acidity is one of the main limiting factors for coffee production in Peruvian rainforests. The objective of this study is to predict the spatial acidity variability for recommending site-specific liming and phosphorus fertilization treatments. We analyzed thirty-six edaphoclimatic variables, eight methods for estimating liming doses, and three geospatial variables from 552 soil samples in the Pichanaqui district of Peru. Multivariate statistics, nonparametric comparison, and geostatistical analysis with Ordinary Kriging interpolation were used for data analysis. The results showed low coffee yields (0.70 ± 0.16 t ha⁻¹) due to soil acidification. The interquartile ranges (IQR) were found to be 3.80–5.10 for pH, 0.21–0.87 cmol Kg⁻¹ for Al⁺³, and 2.55–6.53 mg Kg⁻¹ for available P, which are limiting soil conditions for coffee plantations. Moreover, pH, Al⁺³, Ca⁺², and organic matter (OM) were the variables with the highest accuracy and quality in the spatial prediction of soil acidity (R² between 0.77 and 0.85). The estimation method of liming requirements, MPM (integration of pH and organic material method), obtained the highest correlation with soil acidity-modulating variables and had a high spatial predictability (R² = 0.79), estimating doses between 1.50 and 3.01 t ha⁻¹ in soils with organic matter (OM) > 4.00%. The MAC (potential acidity method) method (R² = 0.59) estimated liming doses between 0.51 and 0.88 t ha⁻¹ in soils with OM < 4.00% and potential acidity greater than 0.71 cmol Kg⁻¹. Regarding phosphorus fertilization (DAP), the results showed high requirements (median = 137.21 kg ha⁻¹, IQR = 8.28 kg ha⁻¹), with high spatial predictability (R² = 0.74). However, coffee plantations on Ferralsols, with Paleogene parental material, mainly in dry forests, had the lowest predicted fertilization requirements (between 6.92 and 77.55 kg ha⁻¹ of DAP). This research shows a moderate spatial variation of acidity, the need to optimize phosphorus fertilization, and an optimal prediction of liming requirements using the MPM and MAC methods, which indicate high requirements in the southwest of the Pichanaqui district.
The conversion of forests to agricultural croplands significantly depletes soil organic carbon reserves, total nitrogen, and available potassium, reaching critical thresholds in the Peruvian Amazon
(Frontiers Media S.A., 2025-09-19) Solórzano Acosta, Richard Andi; Cruz Luis, Juancarlos Alejandro; Chuchon Remon, Rodolfo Juan; Romero Chávez, Lorena Estefani; Lozano, Andi; Gaona Jimenez, Nery; Vallejos Torres, Geomar
Introduction: Land-use change from primary forests to agricultural croplands can degrade soil quality by depleting soil organic carbon (SOC), total nitrogen (STN), and soil-available potassium (SAK). The magnitudes and thresholds of these losses in the Peruvian Amazon remain insufficiently quantified. Methods: We assessed six land-use systems—two primary forests and four croplands (coffee, cocoa, oil palm, camu camu)—collecting 72 surface soil samples (0–20 cm) from 12 subplots per system using pit sampling. SOC, STN, and SAK were measured with standard laboratory procedures and compared across land uses. Results: The humid primary forest (WE–PF) had the highest nutrient status (SOC 118.99 t C ha⁻¹; STN 0.35%; SAK 181.83 mg kg⁻¹). The lowest values occurred in croplands, especially camu camu (SOC 23.93 t C ha⁻¹; STN 0.08%). Forest-to-cropland conversion was associated with average reductions of 58.98% (SOC), 59.49% (STN), and 59.66% (SAK). Among crops, coffee showed the smallest deficit (18.04%), whereas camu camu showed the largest SOC deficit (30.92%). Discussion: Converting forests to croplands critically depletes SOC, STN, and SAK, indicating substantial nutrient losses and concomitant deterioration of soil quality. These findings support conserving primary forests and promoting agroforestry and soil-restorative practices to mitigate degradation in the Peruvian Amazon.
Variación espacial de la fertilidad del suelo en la EEA Pichanaki
(Instituto Nacional de Innovación Agraria (INIA), 2026-02-27) Quispe Matos, Kenyi Rolando; Carbajal Llosa, Carlos Miguel; Mejia Maita, Sharon Yahaira; Arroyo Isuiza, Rosa Karen; Fernandez Puquio, Albert Einstein; Romero Chávez, Lorena Estefani; Chuchon Remon, Rodolfo Juan; Cunyas Camayo, Joseph Michael; Granados Dominguez, Nene Nehemias; Solórzano Acosta, Richard Andi; Cruz Luis , Juancarlos Alejandro
Los suelos de la selva alta peruana presentan condiciones edáficas particulares, que derivan de su origen geológico, el régimen climático húmedo y la intensa dinámica de lixiviación de nutrientes. Dichas condiciones, generan procesos de acidificación, pérdida de bases de cambio y heterogeneidad en la fertilidad de los suelos, lo que limita la sostenibilidad de los sistemas agrícolas si no se implementan prácticas de manejo adecuadas (Solórzano et al., 2025). En particular, en la Estación Experimental Agraria (EEA) Pichanaki predominan suelos Leptosol, Cambisol y Regosol éutricos en la sede principal, mientras que en el anexo se distinguen Cambisol dístrico y Alisol háplico (Instituto Nacional de Recursos Naturales [INRENA], 1996). Asimismo, el clima se caracteriza por precipitaciones cercanas a 2000 mm anuales y temperaturas medias de 18 a 24 °C (Cruz-Luis et al., 2025). Estas condiciones confieren a los suelos de la estación características como acidez elevada, baja capacidad de intercambio catiónico efectiva y concentraciones limitadas de calcio, magnesio y potasio, lo que restringe la saturación de bases y acentúa la toxicidad del aluminio en la rizosfera (Quispe et al., 2025). Además, estos suelos ácidos muestran contenidos reducidos de fósforo disponible y materia orgánica, propiedades clave para la sostenibilidad edáfica en ambientes tropicales (Quispe et al., 2025). La combinación de acidez, deficiencia de nutrientes y alta lixiviación derivada de las lluvias intensas contribuye a la degradación química del suelo y limita la eficiencia del uso de fertilizantes (Sitthaphanit et al., 2009). Dichas limitaciones repercuten directamente en los cultivos estratégicos de la región, como el café, cacao y especies forestales, cuya productividad depende de estrategias de fertilización y encalado adaptadas a la variabilidad espacial de las propiedades edáficas. En función de las características particulares que presentan los suelos de la Estación Experimental Agraria Pichanaki, la evidencia científica señala la necesidad de aplicar una estrategia integral de manejo del suelo. Esta estrategia debe incluir la caracterización y elaboración de mapas de la variabilidad espacial de las propiedades físicas y químicas del suelo mediante herramientas de geoestadística y mapeo digital; la identificación de los principales factores limitantes de la fertilidad, como el pH, la acidez intercambiable, el fósforo, las bases de cambio y la materia orgánica; así como el diseño de prácticas de manejo diferenciadas según zonas, tales como el encalado variable, la aplicación localizada de enmiendas orgánicas y la fertilización específica. La implementación de estas prácticas permitirá un uso más eficiente de los insumos agrícolas, el incremento de la productividad y una mejor resiliencia del suelo frente a la degradación (Heuvelink y Webster, 2022; McBratney et al., 2003; Lowenberg-DeBoer y Erickson, 2019). En ese sentido, el presente documento tiene como objetivo brindar los lineamientos técnicos y prácticos para el diagnóstico, la zonificación y el manejo diferenciado de la fertilidad del suelo en la Estación Experimental Agraria Pichanaki, considerando la variabilidad espacial de sus propiedades edáficas, para optimizar el uso de fertilizantes y enmiendas, mejorar la productividad de los cultivos y fortalecer la sostenibilidad y resiliencia de los suelos en condiciones de selva alta