Examinando por Autor "Lastra, Sphyros"

Mostrando 1 - 5 de 5

An evaluation of dryland ulluco cultivation yields in the face of climate change scenarios in the Central Andes of Peru by using the Aquacrop model
(MDPI, 2024-06-26) Flores Marquez, Ricardo; Vera Vílchez, Jesús; Verástegui Martínez, Patricia; Lastra, Sphyros; Solórzano Acosta, Richard
Ullucus tuberosus is an Andean region crop adapted to high-altitude environments and dryland cultivation. It is an essential resource that guarantees food security due to its carbohydrate, protein, and low-fat content. However, current change patterns in precipitation and temperatures warn of complex scenarios where climate change will affect this crop. Therefore, predicting these effects through simulation is a valuable tool for evaluating this crop’s sustainability. This study aims to evaluate ulluco’s crop yield under dryland conditions at 3914 m.a.s.l. considering climate change scenarios from 2024 to 2100 by using the AquaCrop model. Simulations were carried out using current meteorological data, crop agronomic information, and simulations for SSP1-2.6, SSP3-7.0, and SSP5-8.5 of CMIP 6. The results indicate that minimum temperature increases and seasonal precipitation exacerbation will significantly influence yields. Increases in rainfall and environmental CO2 concentrations show an opportunity window for yield increment in the early stages. However, a negative trend is observed for 2050–2100, mainly due to crop temperature stress. These findings highlight the importance of developing more resistant ulluco varieties to heat stress conditions, adapting water management practices, continuing modeling climate change effects on crops, and investing in research on smallholder agriculture to reach Sustainable Development Goals 1, 2, and 13
Climate change impact on cultivated and wild cacao in Peru and the search of climate change-tolerant genotypes
(Wiley, 2021-05-21) Ceccarelli, Viviana; Fremout, Tobias; Zavaleta, Diego; Lastra, Sphyros; Imán Correa, Sixto Alfredo; Arévalo Gardini, Enrique; Rodriguez, Carlos Armando; Cruz Hilacondo, Wilbert Eddy; Thomas, Evert
Aim: Cacao (Theobroma cacao L.) is expected to be vulnerable to climate change. The objectives of this study were to (a) assess the future impact of climate change on cacao in Peru and (b) identify areas where climate change-tolerant genotypes are potentially present. Methods: Drawing on 19,700 and 1,200 presence points of cultivated and wild cacao, respectively, we modelled their suitability distributions using multiple ensemble models constructed based on both random and target group selection of pseudo-absence points and different resolutions of spatial filtering. To estimate the uncertainty of future predictions, we generated future projections for all the ensemble models. We investigated the potential emergence of novel climates, determined expected changes in ecogeographical zones (zones representative for particular sets of growth conditions) and carried out an outlier analysis based on the environmental variables most relevant for climate change adaptation to identify areas where climate change-tolerant genotypes are potentially present. Results: We found that the best modelling approaches differed between cultivated and wild cacao and that the resolution of spatial filtering had a strong impact on future suitability predictions, calling for careful evaluation of the effect of model selection on modelling results. Overall, our models foresee a contraction of suitable area for cultivated cacao while predicting a more positive future for wild cacao in Peru. Ecogeographical zones are expected to change in 8%–16% of the distribution of cultivated and wild cacao. We identified several areas where climate change-tolerant genotypes may be present in Peru. Main conclusions: Our results indicate that tolerant genotypes will be required to facilitate the adaptation of cacao cultivation under climate change. The identified cacao populations will be target of collection missions.
Compost quality optimization through Plackett-Burman’s design
(OICC Press, 2024-08-28) Ortiz Dongo, Luis Felipe; Mendez Revollar, Yerly; Solorzano Acosta, Richard; Lastra, Sphyros; Carrion Carrera, Gladys
Purpose: This research aimed at compost quality optimization through Plackett-Burman’s design application.This statistical method was used to identify and evaluate key factors that impact compost quality and determine its optimal levels. Method: Eight experiments were carried out with variables such as leachate recirculation, Carbon/Nitrogen ratio,manure type, bacterial and fungi incorporation, type of plant material, and compost pile height. Results: Obtained results revealed significant influence of guinea pig manure in compost quality, improving pH and electric conductivity (dS∙m-1) values, as well as its influence on purple corn fresh and dry weight increase. However, the use of guinea pig manure can increase arsenic, mercury, and lead compost levels, but within the range allowed by Peruvian technical standards. Leachate recirculation showed significant effect on compost humidity increase, which decreased its physical quality to not permitted values by Peruvian technical standards. In addition, leachate uses a reduced number of corn leaves, as well as its fresh and dry weight. It was possible to identify optimal conditions to maximize composting process efficiency, through Plackett-Burman’s Design. Conclusion: These findings provide a solid foundation for composting practice's continuous improvement, contributing to high-quality organic fertilizer production more efficiently and sustainably. This study has the potential to guide future research and feasible applications in the agricultural field, favoring more environmentally friendly practices adoption.
Digital soil mapping of metals and metalloids in croplands using multiple geospatial data and machine learning, implemented in GEE, for the Peruvian Mantaro Valley
(Elsevier, 2024-03-29) Pizarro Carcausto, Samuel; Vera Vilchez, Jesús; Huamani, Joseph; Cruz, Juancarlos; Lastra, Sphyros; Solórzano Acosta, Richard; Verástegui Martínez, Patricia
Quality and safety of the soil are essential to ensure social and economic development and provides the supply of contaminant free food. With agriculture intensification, expansion of urban zones, construction of roads, and mining, some agricultural soils sites become polluted increasing environmental risks to ecosystems functions and human health. Hence the need know the spatial distribution of elements in soils, we mapped 25 elements, namely Ca, Mg, Sr, Ba, Be, K, Na, As, Sb, Se, Tl, Cd, Zn, Al, Pb, Hg, Cr, Ni, Cu, Mo, Ag, Fe, Co, Mn and V, using various geospatial datasets, such as remote sensing, climate, topography, soil data, and distance, to establish the spatial estimation models of spatial distribution trained trough machine learning model with a supervised dataset of 109 topsoil samples, into Google earth engine platform. Using R2, RMSE and MAE to assess the prediction accuracy. First Random Forest gave satisfactory results in predicting the distribution of analyzed elements in soil, being improved for some elements when adds more trees. Additionally, each element analyzed has a different combination of environmental covariates as predictor, mainly soil, climate, topographic and distance variables especially croplands close to rivers, with less importance for spectral variables. Our results suggest that is possible to identify polluted soils and improved regulations to minimize harm to environmental health and human health, for short-to-medium-term environmental risk control.
Diversidad genética de cacao en el Perú
(Bioversity International, 2023-09-30) Thomas, Evert; Imán Correa, Sixto Alfredo; Atkinson, Rachel; Zavaleta, Diego; Rodriguez, Carlos; Lastra, Sphyros; Murrieta, Edgardo; Farfán, Abel; Castro, Juan; Ramírez, José; Samanamud Curto, Angelo Francisco; Paredes Meneses, Cleydi; Arango, Karina; Cruz, Wilbert; Ramírez, Marleni; Zhang, Dapeng
El principal objetivo de este capítulo es dar a conocer la gran diversidad de cacaos que existen en el Perú para promover tanto su uso como su conservación. El capítulo demuestra que la mayoría de los diferentes cultivares tradicionales y grupos genéticos silvestres tienen una coherencia geográfica que permitirá la implementación de un sistema de denominación de origen para el cacao nativo peruano. Para poner en práctica dicho sistema es crítico tener identificado y tener acceso a materiales puros de cada grupo genético, para así poder apoyar a los agricultores, cooperativas y asociaciones, compradores, inversionistas o autoridades públicas, entre otros, en sus esfuerzos de producir y marquetear cacaos de calidad de origen nativo puro.