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The fate of rice crop residues and context-dependent greenhouse gas emissions: Model-based insights from Eastern India

Sonam Sherpa virender kumar Andrew Mcdonald (2024)

Crop residue burning is a common practice in many parts of the world that causes air pollution and greenhouse gas (GHG) emissions. Regenerative practices that return residues to the soil offer a ‘no burn’ pathway for addressing air pollution while building soil organic carbon (SOC). Nevertheless, GHG emissions in rice-based agricultural systems are complex and difficult to anticipate, particularly in production contexts with highly variable hydrologic conditions. Here we predict long-term net GHG fluxes for four rice residue management strategies in the context of rice-wheat cropping systems in Eastern India: burning, soil incorporation, livestock fodder, and biochar. Estimations were based on a combination of Tier 1, 2, and 3 modelling approaches, including 100-year DNDC simulations across three representative soil hydrologic categories (i.e., dry, median, and wet). Overall, residue burning resulted in total direct GHG fluxes of 2.5, 6.1, and 8.7 Mg CO2-e in the dry, median, and wet hydrologic categories, respectively. Relative to emissions from burning (positive values indicate an increase) for the same dry to wet hydrologic categories, soil incorporation resulted in a −0.2, 1.8, or 3.1 Mg CO2-e change in emissions whereas use of residues for livestock fodder increased emissions by 2.0, 2.1, or 2.3 Mg CO2-e. Biochar reduced emissions relative to burning by 2.9 Mg CO2-e in all hydrologic categories. This study showed that the production environment has a controlling effect on methane and, therefore, net GHG balance. For example, wetter sites had 2.8–4.0 times greater CH4 emissions, on average, than dry sites when rice residues were returned to the soil. To effectively mitigate burning without undermining climate change mitigation goals, our results suggest that geographically-target approaches should be used in the rice-based systems of Eastern India to incentivize the adoption of regenerative ‘no burn’ residue management practices.

Article

Soil Carbon Rice Residue Burning Life Cycle Assessment CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SOIL CARBON RICE LIFE CYCLE GREENHOUSE GASES CLIMATE CHANGE

Plantas herbáceas de la duna costera en Sabancuy, Campeche, México

Eliana Josefína Noguera Savelli (2022)

Como parte del Golfo de México, Campeche ocupa el séptimo lugar a nivel nacional por la extensión de su litoral. En general los ecosistemas costeros del país se encuentran afectados por la pérdida de biodiversidad debido al desarrollo de las actividades humanas, aumento de zonas urbanas, turismo y/o actividades agrícolas; situación que también ocurre en la zona de Sabancuy. En este trabajo se presenta un listado de las especies herbáceas que crecen en un fragmento de duna costera en la zona de Sabancuy, el objetivo fue identificar especies de plantas nativas que puedan ser de utilidad en estrategias para la restauración de zonas que se encuentran deforestadas. Es importante conocer la diversidad de las plantas que aún persisten en dunas costeras, en este caso de Sabancuy, a fin de permitir el diseño de planes que faciliten la reforestación y conservación de estos ecosistemas.

Article

COSTA FLORA PLAYA VEGETACION XEROFÍTICA CONSERVACION BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Agricultural lime value chain efficiency for reducing soil acidity in Ethiopia

Moti Jaleta (2023)

Soil acidity is challenging agricultural production in Ethiopia. Above 43% of the farmland is under soil acidity problem and it leads to low crop yields and production losses. Ag-lime is widely considered as an effective remedy for amending soil acidity. This study assesses the current structure of ag-lime value chain and its functionality focusing on central parts of Ethiopia where lime is produced and channeled to acidity affected areas. The study uses Ethiopia as a case study and applies qualitative methods such as key informant interviews and focus group discussions to collect data from different actors in the ag-lime value chain. Key findings indicate that both public and private ag-lime producing factories are operating below their capacity. Due to limited enabling environments, the engagement of private sector in ag-lime value chain is minimal. In addition, farmers have a good awareness of soil acidity problem on their farms, and its causes and mitigation strategies in all regions. However, the adoption of ag-lime by smallholders was minimal. Overall, the current structure of the ag-lime value chain appears fragmented and needs improvement. Addressing soil acidity challenge through efficient ag-lime value chain could narrow lime supply-demand mismatches and increase widespread adoption by farmers to enhance crop productivity and food security in acidity-prone areas of the country.

Article

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA LIMES PRODUCTION COSTS VALUE CHAINS SOIL PH

Análisis de velocidad de soldadura robotizada para proceso MIG en acero1045 AISI

Carlos Eduardo Hernández Acero (2022)

Esta investigación denominada “análisis de velocidad de soldadura robotizada para proceso MIG en acero 1045 AISI” busca el desarrollo de un modelo matemático que permita, mediante parámetros conocidos, el cálculo de la penetración de soldadura en piezas unidas con proceso Metal Inert Gas (MIG). El objetivo se centra en buscar la combinación de valores paramétricos para la velocidad de soldadura, el voltaje y la corriente, los que se obtienen mediante la aplicación de un diseño experimental, que, ejecutadas en el proceso, pueda lograr una penetración de soldadura aceptable para la unión de la pieza. El modelo de superficie de respuesta aplicado fue un diseño de experimentos 2k con diseño central compuesto, y posteriormente el modelo se utilizó para estimar la velocidad de soldadura. Este diseño de experimentos se ejecutó por medio del programa estadístico Minitab versión 17. (Hernández Acero et al., 2022). Una vez teniendo la penetración de soldadura deseada en la pieza, se puede calcular la velocidad de soldadura necesaria para el cálculo de tiempo ciclo y utilizar los parámetros definidos de corriente y voltaje. Los valores de estos factores serán útiles para comenzar la programación del robot ya con la celda funcional y reducir el tiempo de arranque en automático (Hernández Acero et al., 2022).

This research, named “robotic welding speed analysis for MIG process in 1045 AISI steel”, seeks to develop a mathematical model that allow, through know parameters, the calculation of welding penetration in parts joined with Metal Inert Gas (MIG) process. The objective is focused on finding the combination of parametric values for robot welding speed, voltage and current, which are obtained through the application of a design of experiments, which, executed in the process, can achieve an acceptable welding penetration for the union of the part. The response surface model applied was a 2k design of experiments with central composite design, and subsequently the model was used to estimate the welding speed. This design of experiments was obtained using the statistical software Minitab version 17. (Hernández Acero et al., 2022). Once having the desired welding penetration in the part, it can calculate the welding speed necessary for the cycle time calculation and use the defined parameters of current and voltage to start programming the robot with the functional cell and reduce the time of startup (Hernández Acero et al., 2022).

Master thesis

Soldadura MIG Penetración Tiempo ciclo Velocidad de soldadura MIG welding Penetration Cycle time Welding speed INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Development and demographic parameters of Fall Armyworm (Spodoptera frugiperda J.E. Smith) when feeding on rice (Oryza sativa)

Timothy Joseph Krupnik (2023)

Fall Armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), native to the Americas, is a polyphagous insect pest feeding on more than 350 plant species. We studied the developmental and demographic parameters of the maize (Zea mays) strain of FAW on rice (Oryza sativa), and compared the results with its prime host, maize. The developmental period from egg to adult among rice varieties did not differ significantly; however, it did differ significantly between rice and maize, as feeding on rice rather than maize extends development duration of FAW larvae by 15.15%. FAW larvae collected and reared on maize were found to be of significantly higher weight than those reared on rice at two sequential dates of their development; pupal weight however was observed as statistically similar between these two host crops. Regardless of the host, female adults always emerged before males; in maize, female FAW appeared 3.36 days earlier than males. Females derived from rice had longer pre-oviposition periods and shorter oviposition ones than those derived from maize. In rice and maize, the age-specific fecundity rate (mx) peaked at 40 days and 33 days, respectively. When the Fall Armyworm consumed maize instead of rice, there was an increase in the reproduction rate (R 0), the intrinsic rate of natural increase (rm), and the finite rate of increase (λ). For instance, when FAW fed on rice, the rm value was 0.121, whereas it rose to 0.173 when FAW fed on maize. Feeding on rice instead of maize resulted in significantly longer mean length of generation (tG) and doubling time (tD) for the fall armyworm (FAW). This suggests that it took a longer time for the FAW population to double when it was fed rice under controlled greenhouse conditions. In summary, our research suggests that FAW can survive and complete its life cycle on rice plants and on multiple varieties of rice in Bangladesh. However, field verification is necessary before drawing strong conclusions as to the risk posed by FAW in rice. This requires additional studies of FAW and associated insect community dynamics under non-controlled conditions and in the context of multi-species interactions in Asian rice fields.

Article

Invasive Pest Life Table Parameters CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA HOST PLANTS PESTS RICE SPODOPTERA FRUGIPERDA FALL ARMYWORMS

Evaluación de la disponibilidad de la energía y la potencia de las olas: determinación de las condiciones medias y extremas de oleaje en la zona costera: informe de avance

José Antonio Salinas Prieto María Eugenia Maya Magaña (2018)

Se presenta el avance el proyecto que tiene como objetivo identificar las costas mexicanas con mayor potencial energético, caracterizando su distribución espectral, utilizando tanto simulaciones numéricas como observaciones para diseñar e implementar dispositivos adecuados de generación de energía.

Working paper

Energía del oleaje Costas [litoral] CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

El precio del tratamiento de las aguas residuales

CARL ANTHONY SERVIN JUNGDORF Gabriela Mantilla Morales (2017)

Se analiza la estructura del precio del tratamiento de aguas residuales, utilizando como modelo una planta mecanizada de lodos activados o similar, por ser este tipo de planta las que tienden a abandonarse debido al alto costo por consumo de energía. Si bien se tienen conceptos que elevan el precio, también se abre la posibilidad de incorporar operaciones que permitan generar ahorros para tener como efecto la disminución del precio, o la generación de ingresos para pagar parte o la totalidad de los costos, e inclusive tener utilidad. Se concluye que analizar integralmente el precio de tratamiento del agua residual, entendido éste como el monto que cubre la totalidad de los costos obteniendo además de generar cierto margen de utilidad, permite tener un panorama completo para establecer las políticas y acciones encaminadas a sufragar la operación del sistema de saneamiento, incluidos: la conducción, el tratamiento y la disposición y/o reúso de las aguas residuales.

Conference paper

Tratamiento de aguas residuales Costos y análisis de costo INGENIERÍA Y TECNOLOGÍA