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Soil moisture content and maize grain yield under conventional and conservation agriculture practices - results of short term field tests in liselo, Namibia

Christian Thierfelder (2023, [Artículo])

This article focuses on the results from trials developed to monitor the short-term effects of conventionally tilled systems versus CA on soil quality and crop productivity under conditions of the major cropping systems in central, north-central and north-eastern regions of Namibia. Conventional tillage (CT), Minimum tillage (MT), Minimum tillage, mulch (MT-M), Minimum tillage, rotation (MT-R) and Minimum tillage, mulch and rotation (MT-MR) were the primary treatments tested. Significant differences (p≤0.000) among the treatments were observed in the 0-60 cm soil profiles where MT-M plots had the highest soil moisture content (39.8 mm, Standard Error of Mean 0.2815) over the study period. A significant difference (p=0.0206) in grain yield was observed in the second season with CT plots yielding the highest grain yield (3852.3 kg ha-1, standard error of mean 240.35). Results suggest that CA has the potential to increase water conservation and contribute to reduction of the risk of crop failure. Climate change driven degradation under conventional tillage necessitate alternative sustainable tillage methods. Conservation tillage methods and conservation agricultural practices that minimize soil disturbance while maintaining soil cover need to be adopted more locally as viable alternatives to conventional tillage.

Grain Yield Soil Moisture Content CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE CONVENTIONAL TILLAGE GRAIN YIELDS SOIL WATER CONTENT MAIZE

Changes in soil organic carbon pools after 15 years of Conservation Agriculture in rice (Oryza sativa)-wheat (Triticum aestivum) cropping system of eastern Indo-Gangetic plains

C.M. Parihar Mahesh Gathala ML JAT (2023, [Artículo])

The present study was carried out at Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar during 2021-2023 to focus on examining alterations in SOC pools resulting from conservation agriculture (CA) practices in R-W system in the eastern IGP, following the collection of soil samples from a long-term trial that was initiated in rainy (kharif) season 2006. The trial included eight combinations, namely: conventional tilled rice (Oryza sativa L.) and wheat (Triticum aestivum L.) (CTR-CTW); CT rice and zero till wheat (CTR-ZTW); direct seeded rice (DSR) and wheat on permanent raised beds (PBDSR-PBW); ZTDSR and CT Wheat (ZTDSR-CTW); ZTDSR and ZT wheat without residue (ZTDSR-ZTW-R); ZTDSR-ZT wheat with residue (ZTDSR-ZTW +R); unpuddled transplanted riceZTW (UpTR-ZTW) and ZTDSR-sesbania brown manure-ZTW (ZTDSR-S-ZTW). Results revealed that implementing zero tillage (ZT) combined with residue retention in rice and wheat cultivation led to enhanced levels of soil organic carbon (SOC) across all four fractions, namely very labile (CVL), labile (CL), less labile (CLL), and non-labile (CNL), in comparison to the continuous and rotational tillage practices. The tillage and residue management options significantly affected the lability index (LI) and C pool index (CPI), with zero-tillage and residue retention leading to lower LI and higher CPI values. The management practices significantly affected the C management index (CMI), with zero-tillage and residue retention showing the highest CMI values. Findings showed the potential of CA practices for enhancing soil C quality as well as C sequestration in soil of the Eastern IGP of India.

Carbon Management Index Soil Organic Carbon Fractions CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE SOIL ORGANIC CARBON ZERO TILLAGE

Adsorption and Photocatalytic Degradation of Methylene Blue in Carbon Nanotubes: A Review with Bibliometric Analysis

Hugo Albeiro Saldarriaga Noreña MARIO ALFONSO MURILLO TOVAR JOSEFINA VERGARA SANCHEZ JEANNETE RAMIREZ APARICIO Lorena Magallón Cacho MARIA LUISA GARCIA BETANCOURT (2023, [Artículo])

Wastewater-containing dyes are an environmental problem. The prime source of dye pollutants is the textile industry, such as paper manufacturing, food processing, leather, pigments, etc. Dye removal from wastewater using nanotechnology has received attention in recent decades thanks to efficient nanomaterials improving traditional technologies. In recent years, multiple research reports on carbon nanotubes for dye removal and photocatalytic dye degradation provided substantial insight into the comprehension of nanotechnology and remediation. This work presents a review and bibliometric analysis of carbon nanotubes for dye removal and photocatalytic dye degradation, which have an environmental impact today. The bibliometric study showed that the current research tendency on carbon nanotubes applied in dye removal and photocatalysis is still growing. According to research, this work observed that carbon nanotubes for dye removal exhibit high removal and efficient photocatalysis activity, indicating the functionality of nanotechnology for environmental remediation. The analysis of the parameters involved in the removal studies, such as temperature and pH, showed adsorption behavior. The photodegradation of methylene blue demonstrated the photocatalytic activity of carbon nanotubes attributed to the sp2 lattice of graphitic configuration.

BIOLOGÍA Y QUÍMICA QUÍMICA adsorption; carbon nanotubes; methylene blue; photocatalysis; photodegradation of methylene blue

Estudio de la erosión costera en Cancún y la Riviera Maya, México

PEDRO ANTONIO GUIDO ALDANA ADRIANA MARIA RAMIREZ CAMPEROS SERGIO CRUZ LEON ARTURO BRUNO JUAREZ LEON (2009, [Artículo])

La zona turística de Cancún y la Riviera Maya, en el estado de Quintana Roo, constituye uno de los desarrollos turísticos más importantes de México. Debido a su ubicación geográfica, la región en estudio es altamente vulnerable a los ciclones tropicales. Mediante visitas técnica y el análisis de imágenes satelitales, especialistas del Instituto Mexicano de Tecnología del Agua, de la Universidad Autónoma de México y del Instituto Politécnico Nacional se dieron a la tarea de estudiar las posibles causas de la erosión costera con el fin de proponer algunas soluciones. Para lograr tal objetivo, la zona turística se caracterizó de acuerdo con su problemática particular. El análisis de la información obtenida permite afirmar que las causas de la erosión son tanto naturales (interacción de procesos climáticos, meteorológicos, hidrodinámicos y sedimentarios con la morfología costera) como antropogénicas (ocupación de la duna litoral por parte de particulares, construcción desordenada de obras de protección). Pudo concluirse que las soluciones propuestas para detener la erosión costera deberían seleccionarse desde un punto de vista integral y además ser blandas, como lo es la alimentación artificial con arena.

Playas Erosión de playas Alimentación artificial de arena CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Mulch application as the overarching factor explaining increase in soil organic carbon stocks under conservation agriculture in two 8-year-old experiments in Zimbabwe

Regis Chikowo Christian Thierfelder Marc Corbeels (2024, [Artículo])

Conservation agriculture (CA), combining reduced or no tillage, permanent soil cover, and improved rotations, is often promoted as a climate-smart practice. However, our understanding of the impact of CA and its respective three principles on top- and subsoil organic carbon stocks in the low-input cropping systems of sub-Saharan Africa is rather limited. This study was conducted at two long-term experimental sites established in Zimbabwe in 2013. The soil types were abruptic Lixisols at Domboshava Training Centre (DTC) and xanthic Ferralsol at the University of Zimbabwe farm (UZF). The following six treatments, which were replicated four times, were investigated: conventional tillage (CT), conventional tillage with rotation (CTR), no tillage (NT), no tillage with mulch (NTM), no tillage with rotation (NTR), and no tillage with mulch and rotation (NTMR). Maize (Zea mays L.) was the main crop, and treatments with rotation included cowpea (Vigna unguiculata L. Walp.). The soil organic carbon (SOC) concentration and soil bulk density were determined for samples taken from depths of 0–5, 5–10, 10–15, 15–20, 20–30, 30–40, 40–50, 50–75 and 75–100 cm. Cumulative organic inputs to the soil were also estimated for all treatments. SOC stocks at equivalent soil mass were significantly (p<0.05) higher in the NTM, NTR and NTMR treatments compared with the NT and CT treatments in the top 5 cm and top 10 cm layers at UZF, while SOC stocks were only significantly higher in the NTM and NTMR treatments compared with the NT and CT treatments in the top 5 cm at DTC. NT alone had a slightly negative impact on the top SOC stocks. Cumulative SOC stocks were not significantly different between treatments when considering the whole 100 cm soil profile. Our results show the overarching role of crop residue mulching in CA cropping systems with respect to enhancing SOC stocks but also that this effect is limited to the topsoil. The highest cumulative organic carbon inputs to the soil were observed in NTM treatments at the two sites, and this could probably explain the positive effect on SOC stocks. Moreover, our results show that the combination of at least two CA principles including mulch is required to increase SOC stocks in these low-nitrogen-input cropping systems.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SOIL ORGANIC CARBON CONSERVATION AGRICULTURE EXPERIMENTATION CROP MANAGEMENT

Desarenadores fluídicos de tubo de vórtice: un estudio experimental

ALDO IVAN RAMIREZ OROZCO ROBERTO MEJIA ZERMEÑO JESUS ANTONIO BLANCO FIGUEROA (2007, [Artículo])

El desarenador fluídico de tubo de vórtice es un dispositivo utilizado para la extracción de sedimentos de cauces o canales y está formado por un tubo con una ranura abierta a lo largo de su parte superior instalado en el fondo del cauce. La mezcla de agua-sedimento que fluye cerca del fondo del cauce es atrapada por el tubo y expulsada hacia un canal de extracción con la ayuda del vórtice que se forma en el interior del tubo. El funcionamiento del dispositivo se evalúa por medio de la eficiencia de atrapamiento, la cual se define como la relación entre el gasto sólido extraído y el gasto sólido total transportado, y por la eficiencia de extracción, que se define como la relación entre el gasto líquido extraído a través del tubo y el gasto líquido conducido por el cauce. En este artículo se presentan los resultados de pruebas experimentales llevadas a cabo en un desarenador de este tipo en el laboratorio Enzo Levi, del Instituto Mexicano de Tecnología del Agua. Los resultados indican que se logran eficiencias de atrapamiento de hasta 94.9%, con relaciones de extracción que no sobrepasan el 10% en todas las pruebas realizadas.

Desarenadores Sedimentos Canales de riego INGENIERÍA Y TECNOLOGÍA

Programa regional hidrológico forestal para la región I península de Baja California

Maria Dolores Olvera Salgado HECTOR GREGORIO CORTES TORRES (2007, [Documento de trabajo])

Tabla de contenido: Planeación en material forestal – Objetivos, metas y estrategias en la Gerencia Región Conafor – Relación agua-bosque – Diagnóstico forestal – Necesidades de recuperación forestal – Planeación estratégica de inversiones para la conservación y recuperación forestal – Impactos esperados de la recuperación forestal sobre los principales recursos naturales – Participación social y planeación regional en materia forestal – Fuentes de financiamiento para implementar el PRHF en la región I península de Baja California – Otros componentes del programa regional hidrológico forestal – Conclusiones y recomendaciones – Bibliografía.

Planeación en material forestal – Objetivos, metas y estrategias en la Gerencia Región Conafor – Relación agua-bosque – Diagnóstico forestal – Necesidades de recuperación forestal – Planeación estratégica de inversiones para la conservación y recuperación forestal – Impactos esperados de la recuperación forestal sobre los principales recursos naturales – Participación social y planeación regional en materia forestal – Fuentes de financiamiento para implementar el PRHF en la región I península de Baja California – Otros componentes del programa regional hidrológico forestal – Conclusiones y recomendaciones – Bibliografía.

Bosques Planificación ambiental Erosión hídrica Informes de proyectos Baja California CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA