CARACTERIZACIÓN QUÍMICA DE ABONOS ORGÁNICOS ENRIQUECIDO CON GUANO DE MURCIÉLAGO

An alternative to solve the problem of agroindustrial residues is composting, so the objective of this study was to chemically characterize the composts elaborated with agroindustrial byproducts and enriched with bat guano. To generate the compost treatments, a 3X4 factorial design was used with Saccharum spp. sludge, banana (Musa sp.) waste, cacao (Theobroma cacao L.) chaff, in the amounts of 20, 30, 40 and 50 kg each; and 30, 20, 10 and 0 kg of bat guano in commercial presentation. The Indore process was used with four repetitions. For the control of maturity, the temperature, moisture and ammonium/nitrate relation were evaluated. The temperature changes during the composting process allowed identifying the mesophyll, thermophyll and mesophyll phases; the moisture and the NH4+/ NO3? relation confirmed the maturity of the composts, and the pH varied from acid to alkaline, considering this as a beneficial for differentiated applications on the soil. The values of pH, CE, MO, N, and Moisture, as well as the contents of P, K, Ca, Mg, Fe, Cu, Zn and Mn from the composts suggest good quality for the soil supply.Una alternativa para solucionar el problema de los residuos agroindustriales es el composteo, por ello el objetivo de este trabajo fue caracterizar químicamente las compostas elaboradas con subproductos agroindustriales y enriquecidas con guano de murciélago. Para generar los tratamientos de composta, se utilizó un diseño factorial 3x4 con cachaza de Saccharum spp., desecho de plátano (Musa sp.), cascarilla de cacao (Theobroma cacao L.), en cantidades de 20, 30, 40 y 50 kg cada uno; y 30, 20, 10 y 0 kg de guano de murciélago en presentación comercial. Se utilizó el proceso Indore con cuatro repeticiones. Para el control de madurez se evaluó la temperatura, humedad, y relación amonio/nitrato. Los cambios de temperatura durante el proceso de composteo permitieron identificar las fases mesófila, termófila y mesófila; la humedad y la relación NH4+/ NO3? confirmaron la madurez de las compostas, y el pH varió de ácido a alcalino, considerado como benéfico para aplicaciones diferenciadas al suelo. Los valores de pH, CE, MO, N, y Humedad, así como los contenidos de P, K, Ca, Mg, Fe, Cu, Zn y Mn de las compostas, sugieren buena calidad para suministro al suelo

MÉTODOS PARA EXTRAER CELULOSA DE LA PAJA DE CAÑA DE AZÚCAR (Saccharum spp.)

The objectives of the study were to establish an artisanal process for the extraction of cellulose from sugar cane straw (Saccharum spp.) harvested green, mechanically, and to characterize its quality. The caustic soda method and the artisanal method were used, and industrial reagents were used in the latter. The extraction of cellulose fiber was similar in both cases. The highest amount of cellulose pulp (10.02 g) was extracted with the caustic soda method and it had a cellulose yield higher than 6.96 % compared to the artisanal method. The cellulose extracted from the cane straw was 74.78 % with the caustic soda method and 64.24 % with the artisanal method, based on the XRD technique. The average size of crystals from the straw cellulose was similar with both extraction methods, and it is of the alpha-cellulose type, which can be used for various materials in the pharmaceutical and dietary industries.Los objetivos del trabajo fueron establecer un proceso artesanal para la extracción de celulosa de la paja de caña de azúcar (Saccharum spp.) cosechada en verde, de forma mecánica, y caracterizar su calidad. Se utilizó el método a la sosa y el artesanal, y en este último se utilizaron reactivos de uso industrial. La extracción de fibra de celulosa fue similar en ambos métodos. En el conocido como a la sosa se extrajo la mayor cantidad de pulpa de celulosa (10.02 g) y tuvo un rendimiento de celulosa superior a 6.96 % en comparación con el artesanal. La celulosa extraída de la paja de caña por ambos métodos fue pura, según análisis del FTIR. La cristalinidad de la celulosa de paja fue de 74.78 % a la sosa y 64.24 % con el artesanal, según la técnica de XRD. El tamaño promedio de cristales de la celulosa de paja fue similar en ambos métodos de extracción y es del tipo alfa-celulosa, que puede ser usada para diversos materiales en las industrias farmacéutica y alimenticia

CLASIFICACIÓN DE LOS SUELOS POR FERTILIDAD DE LA SUBREGIÓN RÍOS DE TABASCO, MÉXICO

The system used to classify soils based on their FCC fertility groups the soils of the Ríos de Tabasco sub-region (SRT) according to parameters of the superior soil layer, and some characteristics of the subsoil linked to the growth of palm oil (Elaeis guineensis Jacq.). A soil study of 361,855.9 ha was performed to decide the expansion of the area cultivated with palm oil, classifying the fertility of the SRT soils to improve decision making. The factors that limit the potential of the SRT soils for their agricultural and livestock use were acidity, water excess or deficit, clay content, erosion, nutrient deficiencies, presence of Na, alkalinity and low CIC which, alone or grouped, have an influence on the detriment of soil fertility. Agricultural drainage, whitewashing, irrigation and fertilization with macro and micro nutrients, can be agronomic practices that would allow improving the conditions of the Gleysol, Vertisol, Fluvisol and Acrisol units for palm oil. The rest of the subunits must be conserved with natural vegetation, to conserve their role of buffer and moisture retention zones. To solve these problems, an integral analysis is required which takes into account the type of crop, time of sowing, and availability of technology.El sistema para clasificar suelos de acuerdo a su fertilidad FCC agrupa a los suelos de la subregión Ríos de Tabasco (SRT) de acuerdo a parámetros de la capa superior del suelo, y algunas características del subsuelo vinculadas con el crecimiento de la palma de aceite (Elaeis guineensis Jacq.). Se realizó un estudio de suelos de 361,855.9 ha para decidir la expansión del área cultivada de palma de aceite clasificando la fertilidad de los suelos de la SRT para mejorar la toma de decisiones. Los factores que limitan la potencialidad de los suelos de la SRT para su uso agropecuario fueron la acidez, exceso o déficit de agua, contenido de arcilla, erosión, deficiencias nutrimentales, presencia de Na, alcalinidad y baja CIC que, solos o agrupados influyen en el detrimento de la fertilidad de los suelos. El drenaje agrícola, encalado, riego y fertilización con macro y micronutrimentos, pueden ser prácticas agronómicas que permitirían mejorar las condiciones de las unidades Gleysol, Vertisol, Fluvisol y Acrisol para la palma de aceite. El resto de las subunidades deben ser conservadas con la vegetación natural y, para conservar su papel de amortiguamiento y retención de humedad. Para resolver estos problemas se requiere un análisis integral que considere el tipo de cultivo, época de siembra y disponibilidad de tecnología

OPCIONES DE FERTILIZACION PARA EL CULTIVO DE CAÑA DE AZUCAR (Saccharum spp.) EN TABASCO, MÉXICO

Organic fertilization can be superior to chemical fertilization in some nutritional and growth parameters. With the objective of evaluating alternative sources of nutrition for sugar cane (Saccharum spp.) cultivation in Tabasco, México, the nitrogen fixing species Canavalia ensiformis and Cajanus cajan were evaluated, with three compost doses and one biofertilizer in a Cambisol fluvic soil (Clayey Eutric), compared to chemical fertilization and an absolute witness of the cultivar Mex 79-431. It was found that the nutritional demand from the crop was K>N>P, evidencing good growth with relation to straw-stem of 0.33. C. ensiformis showed higher competition to the crop than C. cajan. In the plantilla and soca cycles, average yields of 67 t ha-1 and 102 t ha-1 were found, respectively, although no significant statistical differences were recorded between the treatments. In the soca cycle, leaf deficiencies of N and K were observed, and K deficiency in the soil without reflecting an effect on the quality of the juice in any cycle as a result of the type of fertilizationLa fertilización orgánica puede ser superior a la fertilización química en algunos parámetros nutrimentales y de crecimiento. Con el objetivo de evaluar fuentes alternativas de nutrición al cultivo de caña de azúcar (Saccharum spp.) en Tabasco, México, se evaluaron las especies fijadoras de nitrógeno Canavalia ensiformis y Cajanus cajan, tres dosis de composta y un biofertilizante en un suelo Cambisol flúvico (Arcíllico Éutrico), comparados con fertilización química y un testigo absoluto en la variedad Mex 79-431. Se registró que la demanda nutrimental del cultivo fue K>N>P, evidenciando buen crecimiento con relación paja-tallo de 0.33. C. ensiformis registró mayor competencia al cultivo que C. cajan. En los ciclos plantilla y soca se lograron rendimientos medios de 67 t ha-1 y 102 t ha-1 respectivamente, aunque no se registraron diferencias estadísticas significativas entre tratamientos. En el ciclo soca se observaron deficiencias foliares de N y K, y deficiencia de K en el suelo sin reflejar efecto en la calidad del jugo por el tipo de fertilización en ningún ciclo

Arsenic speciation in edible alga samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence spectrometry

Twelve commercially available edible marine algae from France, Japan and Spain and the certified reference material (CRM) NIES No. 9 Sargassum fulvellum were analyzed for total arsenic and arsenic species. Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126 μg g−1. Arsenic species in alga samples were extracted with deionized water by microwave-assisted extraction and showed extraction efficiencies from 49 to 98%, in terms of total arsenic. The presence of eleven arsenic species was studied by high performance liquid chromatography–ultraviolet photo-oxidation–hydride generation atomic–fluorescence spectrometry (HPLC–(UV)–HG–AFS) developed methods, using both anion and cation exchange chromatography. Glycerol and phosphate sugars were found in all alga samples analyzed, at concentrations between 0.11 and 22 μg g−1, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2 μg g−1). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (<0.9 μg g−1) and generally high arsenate (As(V)) concentrations (up to 77 μg g−1) were found in most of the algae studied. The results obtained are of interest to highlight the need to perform speciation analysis and to introduce appropriate legislation to limit toxic arsenic species content in these food products

Penetration of ultraviolet‐B radiation in oligotrophic regions of the oceans during the Malaspina 2010 expedition

Few studies have investigated ultraviolet (UV) radiation in the open ocean besides its harmful effects on organisms and influence on biogeochemical processes. Here, we assessed UV attenuation, with particular focus on UV‐B, across the (sub)tropical ocean during the Malaspina 2010 Circumnavigation. Vertical UV radiometer profiles together with Chl‐ a concentration, and UV absorption by CDOM ( a CDOM ( λ )) and by suspended particulate matter ( a p ( λ )) were measured at 117 stations. At photosynthetically active radiation (PAR) and across UV‐A and UV‐B wavelengths, the lowest downwelling attenuation coefficients ( K d ) during the expedition were recorded in ultra‐oligotrophic regions at 5°–15°S (mean K d (305 nm): 0.129 m −1 , mean K d (313 nm): 0.107 m −1 ) in the Indian and South Pacific Oceans. The waters here were comparatively more transparent than at 5°–15°N (mean K d (305 nm): 0.239 m −1 , mean K d (313 nm): 0.181 m −1 ) where equatorial upwelling occurs. K d was highest near the Costa Rica Dome ( K d (313 nm): 0.226 m −1 ) and at the confluence of the Benguela and Agulhas currents ( K d (313 nm): 0.251 m −1 ). The contribution of a p ( λ ) toward nonwater absorption ( a nw ( λ )) was significantly lower at 305 nm than at 313 and 320 nm, suggesting the contribution of absorption by detritus and phytoplankton particles decreases compared with that of CDOM absorption as UV‐B wavelength decreases. Both a CDOM ( λ ) and a p ( λ ) at UV‐B wavelengths were lowest in the Indian Ocean whereas K d was lowest in the South Pacific. This finding emphasizes that other factors besides absorption, such as scattering by reflective phytoplankton or inorganic particles, strongly influence UV‐B attenuation in open ocean waters.Plain Language Summary: We assessed water transparency to UV‐B radiation across the tropical and subtropical ocean as part of the Malaspina 2010 Expedition. UV‐B radiometer profiles, Chlorophyll‐a, and UV‐B absorption by organic matter and suspended particles were measured at 117 stations. The most UV‐B transparent waters were found in regions where nutrients are extremely low, particularly at 5°–15°S in the Indian and South Pacific Oceans. Here, ocean waters were considerably more transparent than 5°–15°N, which suggests that at a given depth southern hemisphere marine organisms experience higher UV‐B exposure than their northern counterparts. The least UV‐B transparent waters were near the Costa Rica Dome and at the confluence of the Benguela and Agulhas currents. UV‐B absorption by organic matter and suspended particles, and Chl‐ a concentration were lowest in the Indian Ocean. The contribution of suspended particles toward nonwater absorption was significantly lower at 305 nm than at 313 and 320 nm, and higher in the clearest waters of the Indian Ocean than in the Subtropical South Pacific. Absorptions by organic matter and suspended particles were lowest in the Indian Ocean whereas UV‐B attenuation was lowest in the South Pacific, which highlights the complex relationship between optical properties in the UV‐B spectrum.Ministerio de Ciencia e Innovación | Ref. CSD2008-00077King Abdullah University of Science and Technology | Ref. BAS/1/1072-01-0

Nonholonomic constraints in kk-symplectic Classical Field Theories

A $k$-symplectic framework for classical field theories subject to nonholonomic constraints is presented. If the constrained problem is regular one can construct a projection operator such that the solutions of the constrained problem are obtained by projecting the solutions of the free problem. Symmetries for the nonholonomic system are introduced and we show that for every such symmetry, there exist a nonholonomic momentum equation. The proposed formalism permits to introduce in a simple way many tools of nonholonomic mechanics to nonholonomic field theories.Comment: 27 page

Simultaneous optimization of circadian and color performance for smart lighting systems design

We present in this work a method to design lighting sources that can be adapted to different temperatures of color and, simultaneously, with a tunable circadian character. We obtained an acceptable range of tuning in both parameters compared to the bibliography. This kind of lighting source has potential applications particularly in building lighting, but also in farming or agriculture. At the same time, we have shown the possibilities of multiobjective optimizations in the lighting industry. The optimization has been developed using the Genetic Algorithm and multiobjective merit functions. The lighting source is able to work under two different regimes regarding the circadian effect, with a design based on a combination of two monochromatic and two white Lighting Emitting Diodes (enough for controlling the circadian character and the color performance at the same time). A prototype, which can be manually or automatically controlled, has been also implemented and evaluated, with a performance in terms of color coordinates very close to the daylight, showing a modulation of the Circadian Efficacy of Radiation between 6% and 16%, and a Color Rendering Index above 80%

Evaluación exploratoria del cultivo de la caña de azúcar (Saccharum spp.): Enfoque del paisaje del desempeño

Objective: Perform an exploratory analysis of sugar cane (Saccharum spp.) cultivation (CCA) through a performance landscape (PD) approach including an analytical description of the food balance sheet and performance indicators. Design/methodology/approach: Three main dataset were constructed by using different statistic information systems, including eight performance variables-production, exports, imports, consumption per capita, acreage, production value, yield, farm-gate price, revenue per hectare on SCC, sugar products and 82 perennial crops (PC). Analytical description was based on municipality scale and temporal series (2003-2017). PL focused on the assessment of percentage proportion between SCC and PC, considering acreage and production value. Results: Mexican consumption of sugar equivalent was decreasing in spite of its high consumption value (37.5 kg person-1 y-1). For 15 years, production of SCC and its acreage have gradually increased. Since farm gate prices showed a real increment (34%), production value and revenue per hectare (MX55676 ha-1) also revealed growth. In contrast, yield (84 Mg ha-1) stagnated (5%). PL assessment identified 94 municipalities where SCC dominates acreage and production value. Limitations on study/implications: Descriptive analysis is powerful to characterize systems and shed light on improving understanding on the identification of driving factors, selecting a core dataset to measure their impacts and seeking for causality relationships. Findings/conclusions: The integration of different information sources clarify the interrelations between economic, social and environmental themes, particularly in agriculture.Objetivo: Realizar un análisis exploratorio del cultivo de la caña de azúcar (CCA) mediante un enfoque de paisaje del desempeño (PD) incluyendo una descripción analítica de hoja balance alimentaria e indicadores de desempeño. Diseño/metodología/aproximación: Tres tablas de datos fueron construidas usando diferentes sistemas de información estadística (SIE) e incluyendo ocho variables –producción, exportaciones, importaciones, consumo per cápita, superficie, valor de la producción (VP), precio pagado al productor (PP) e ingreso unitario sobre el CCA, productos de azúcar y 82 cultivos perennes (SPAP). La descripción analítica fue basada a nivel municipal y una serie temporal (2003-2017). A través del PD, se evaluó el porcentaje de proporción entre el CCA y los SPAP, considerando superficie y el VP. Resultados: El consumo de azúcar equivalente está disminuyendo (37.5 kg persona-1 año-1). Las exportaciones incrementaron y representaron 40% de la producción; las importaciones crecieron moderadamente, pero existe suficiencia alimentaria. Por 15 años, la producción y superficie del CCA ha crecido gradualmente. Los PP mostraron un crecimiento real (34%), en consecuencia, también el VP y el ingreso unitario ($ 55,676 ha-1). En contraste, el rendimiento (84 Mg ha-1) está estancado (5%). La evaluación del PD identificó 94 municipios donde el CCA domina superficie y VP. Limitaciones del estudio/implicaciones: El análisis descriptivo es una herramienta útil para caracterizar sistemas y proporciona mayor claridad sobre la identificación de factores de cambio, selección de datos centrales, así como de facilitar la búsqueda de relaciones causales. Este tipo de estudios, aporta información a temas económicos de gran visión. sin embargo; en lo social, se carece de relaciones vinculantes entre productores e instituciones que concentran los datos, además de que no contiene información ambiental (clima, suelo, etc.) y de manejo agronómico del cultivo de la caña de azúcar en cada estado de la república mexicana. Hallazgos/conclusiones: La integración de diferentes SIE clarifica las interrelaciones entre los temas económicos, particularmente en agricultur