Effect of poultry manure and biosolid mixed with European turbe for cucurbit seedling production

En México, la turba de Sphagnum (peat moss), es el principal sustrato utilizado para la producción de plántulas de hortalizas en bandeja de poliestireno, su precio es elevado por ser de importación, lo que hace necesario estudiar alternativas de menor costo. Por lo anterior, se propone mezclar la turba con materiales orgánicos de origen local como la gallinaza (G) y biosólido (B) para producir plántulas de pepino (Cucumis sativus L.) y calabacita (Cucurbita pepo L.). Ocho mezclas de material orgánico-turba fueron evaluadas para cada especie: 1) 4% G + 96% turba; 2) 8% G + 92% turba; 3) 12% G + 88% turba; 4) 16% G + 84% turba; 5) 4% B + 96% turba; 6) 8% B + 92% turba; 7) 12% B + 88% turba; 8) 16% B + 84% turba, el tratamiento testigo fue 100% turba. En los resultados se destaca, en pepino, la mezcla con 16% de biosólido que afectó positivamente en unidades SPAD (Soil Plant Analysis Development), diámetro de tallo y área foliar, mientras que la mezcla con 12% de gallinaza aumentó peso seco de parte aérea y total (P ≤ 0,05). En calabacita, la mezcla con 16% de gallinaza incrementó área foliar (P ≤ 0,05). En las variables de altura, peso seco de raíz y balance de plántula no se encontraron diferencias significativas en ambas especies y mezclas. Se concluye que mezclas de turba europea (peat moss) con gallinaza o biosólido, son una importante alternativa técnica y económica para la producción de plántulas en pepino y calabacita.In Mexico, Sphagnum turbe (peat moss) is the main substrate used for the production of vegetable seedlings in polystyrene trays. It is imported and thus has an elevated price, therefore some lower cost alternatives need to be addressed. This work proposes a mixture of peat with local organic materials as poultry manure (PM) and biosolid (B) to produce cucumber (Cucumis sativus L.) and zucchini (Cucurbita pepo L.) seedlings. Eight mixtures of organic material-peat were evaluated for each species: 1) 4% PM + 96% peat; 2) 8% PM + 92% peat; 3) 12% PM + 88% peat; 4) 16% PM + 84% peat; 5) 4% B + 96% peat; 6) 8% B + 92% peat; 7) 12% B + 88% peat; 8) 16% B + 84% peat, and 100% peat as control. Compared with the control, the mixture with 16% of biosolid affected positively SPAD (Soil Plant Analysis Development) units, stem diameter and leaf area in cucumber seedlings, while the mixture with 12% of poultry manure increased aerial and total dry weight (P ≤ 0.05). In zucchini, the mixture with 16% of poultry manure increased leaf area (P ≤ 0.05). No significant differences were found in height, root dry weight and seedling balance in both species and mixtures. We concluded that use of peat moss mixed with poultry manure or biosolid represents an important technical and economic alternative for cucumber and zucchini seedling production.Fil: Carballo Méndez, Fernando de Jesús. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortiz, Juan Carlos. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: García Hernández, José Luis.Fil: Alcalá Jáuregui, Jorge Alonso. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Preciado Rangel, Pablo. Instituto Tecnológico de Torreón (México)Fil: Rodríguez Fuentes, Humberto. Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Villarreal Guerrero, Federico. Universidad Autónoma de San Luis Potosí. Facultad de Agronomí

Contaminación por metales pesados en sedimentos de un área ribereña en San Luis Paotosí, México

The aim of this study was to determine the presence of heavy metal in sediments of a fragmented riparian area, as an indicator of environmental pollution in San Luis Potosi, Mexico. Eleven sampling points, including four different land uses were established: Pond, Agriculture, Livestock and Rural Settlement. Sediment samples were taken during the seasons of spring, summer and autumn 2010, and winter 2011. The technique of ICP-MS was used to determine Pb, Cd, Cu, and Zn data analysis was performed with Minitab®. Land use has an effect on the accumulation of Cu, Zn and Cd, with the agricultural area containing the highest concentrations. The season was a significant factor for concentrations of Zn, Cd and Pb, emphasizing spring 2010 and autumn 2010, respectively. Significant correlations were found between Cu-Zn (r = 0.746), Pb-Cu (r = 0.635) and Cd-Zn (r = 0.720). The normal limits of Cu, Cd, Zn and Pb in sediments established by the Canadian Environmental Quality Guidelines were exceeded. By using other scientific and technical sources, maximum levels of Cu, Cd and Pb were defined with a condition of high pollution. This condition is attributed to the land use change dynamics, to wastewater discharges, and urban, agricultural and livestock wastes. Thus, a further environmental assessment is recomended for the study area.Se determinó la presencia de metales pesados en sedimentos de un sistema ribereño fragmentado por usos de suelo como indicador de contaminación ambiental en San Luis Potosí, México. Se establecieron once puntos de muestreo considerando los usos de suelo: Estanque, agrícola, Asentamiento rural y Ganadero. Durante las estaciones de primavera, verano y otoño de 2010 e invierno 2011, se tomaron muestras de sedimentos. Se utilizó la técnica de ICP-MS para determinar Pb, Cd, Cu and Zn y los datos fueron analizados en Minitab®. El uso de suelo incide en la acumulación de Cu, Zn y Cd, siendo la zona agrícola la que cuenta con mayores concentraciones. La estación fue significativa respecto de las concentraciones de Zn, Cd y Pb, destacando primavera 2010 y otoño 2010 respectivamente. Asimismo, fueron encontradas correlaciones significativas entre Cu-Zn (r = 0,746), Pb-Cu (r = 0,635) y Cd-Zn (r = 0,720). Los límites normales de Cu, Cd, Zn y Pb en sedimentos establecidos por la Canadian Environmental Quality Guidelines fueron rebasados. Con otras fuentes se definieron que los niveles máximos de Cu, Cd y Pb presentaron una condición alta de contaminación. Esta condición es atribuida a la dinámica de usos de suelo, descargas de aguas residuales, desechos sólidos urbanos, agrícolas y ganaderos, recomendándose continuar su evaluación ambiental

Effect of Acid Treatment on the Physicochemical Characteristics and Sorption Capacity of a Natural Zeolite

Mining is a very important industry for the development of emerging economies; however, it generates a large number of environmental externalities such as acid mine drainages; these have acid pH values and high heavy metal content. Although there are several methods for the elimination of metals in different solutions, they require a large economic investment. Recently, the use of adsorbent materials for the removal of heavy metals in acid drains such as agricultural by-products and natural zeolites has been developed as a cheaper alternative. In spite of the environmental benefits of using natural zeolites as adsorbent, one of the disadvantages is dealumination, which to a great extent could depend on the geological origin of the mineral that shapes some of its characteristics. This study characterized chemical and physical properties of natural and modified zeolites using various techniques, such as X-ray diffraction (XRD), N2 adsorption- desorption, inductively coupled plasma − optical emission spectroscopy (ICP-OES), and SEM-EDS to determine the effect of an acid treatment on the physical and chemical characteristics of a natural zeolite, correlating these with their sorption capacity. When giving acid treatment to a zeolite there are no significant changes in the crystal structure, the Si/Al ratio indicates a dealumination of the structure but with minimal changes, the surface area and density of the micropores increased considerably. A significant increase in the capacity of copper adsorption was registered. According to XRD, no significant changes occur to the structures. Keywords: Dealumination; aluminosilicates; AMD; acid treatment; metal removal. DOI: 10.7176/JEES/10-9-05 Publication date:September 30th 202

Spatial near future modeling of land use and land cover changes in the temperate forests of Mexico

The loss of temperate forests of Mexico has continued in recent decades despite wide recognition of their importance to maintaining biodiversity. This study analyzes land use/land cover change scenarios, using satellite images from the Landsat sensor. Images corresponded to the years 1990, 2005 and 2017. The scenarios were applied for the temperate forests with the aim of getting a better understanding of the patterns in land use/land cover changes. The Support Vector Machine (SVM) multispectral classification technique served to determine the land use/land cover types, which were validated through the Kappa Index. For the simulation of land use/land cover dynamics, a model developed in Dinamica-EGO was used, which uses stochastic models of Markov Chains, Cellular Automata and Weight of Evidences. For the study, a stationary, an optimistic and a pessimistic scenario were proposed. The projections based on the three scenarios were simulated for the year 2050. Five types of land use/land cover were identified and evaluated. They were primary forest, secondary forest, human settlements, areas without vegetation and water bodies. Results from the land use/land cover change analysis show a substantial gain for the secondary forest. The surface area of the primary forest was reduced from 55.8% in 1990 to 37.7% in 2017. Moreover, the three projected scenarios estimate further losses of the surface are for the primary forest, especially under the stationary and pessimistic scenarios. This highlights the importance and probably urgent implementation of conservation and protection measures to preserve these ecosystems and their services. Based on the accuracy obtained and on the models generated, results from these methodologies can serve as a decision tool to contribute to the sustainable management of the natural resources of a region

Efecto de gallinaza y biosólido en mezcla con turba europea para producción de plántulas de cucurbitáceas

In Mexico, Sphagnum turbe (peat moss) is the main substrate used for the production of vegetable seedlings in polystyrene trays. It is imported and thus has an elevated price, therefore some lower cost alternatives need to be addressed. This work proposes a mixture of peat with local organic materials as poultry manure (PM) and biosolid (B) to produce cucumber (Cucumis sativus L.) and zucchini (Cucurbita pepo L.) seedlings. Eight mixtures of organic material-peat were evaluated for each species: 1) 4% PM + 96% peat; 2) 8% PM + 92% peat; 3) 12% PM + 88% peat; 4) 16% PM + 84% peat; 5) 4% B + 96% peat; 6) 8% B + 92% peat; 7) 12% B + 88% peat; 8) 16% B + 84% peat, and 100% peat as control. Compared with the control, the mixture with 16% of biosolid affected positively SPAD (Soil Plant Analysis Development) units, stem diameter and leaf area in cucumber seedlings, while the mixture with 12% of poultry manure increased aerial and total dry weight (P ≤ 0.05). In zucchini, the mixture with 16% of poultry manure increased leaf area (P ≤ 0.05). No significant differences were found in height, root dry weight and seedling balance in both species and mixtures. We concluded that use of peat moss mixed with poultry manure or biosolid represents an important technical and economic alternative for cucumber and zucchini seedling production.En México, la turba de Sphagnum (peat moss), es el principal sustrato utilizado para la producción de plántulas de hortalizas en bandeja de poliestireno, su precio es elevado por ser de importación, lo que hace necesario estudiar alternativas de menor costo. Por lo anterior, se propone mezclar la turba con materiales orgánicos de origen local como la gallinaza (G) y biosólido (B) para producir plántulas de pepino (Cucumis sativus L.) y calabacita (Cucurbita pepo L.). Ocho mezclas de material orgánico-turba fueron evaluadas para cada especie: 1) 4% G + 96% turba; 2) 8% G + 92% turba; 3) 12% G + 88% turba; 4) 16% G + 84% turba; 5) 4% B + 96% turba; 6) 8% B + 92% turba; 7) 12% B + 88% turba; 8) 16% B + 84% turba, el tratamiento testigo fue 100% turba. En los resultados se destaca, en pepino, la mezcla con 16% de biosólido que afectó positivamente en unidades SPAD (Soil Plant Analysis Development), diámetro de tallo y área foliar, mientras que la mezcla con 12% de gallinaza aumentó peso seco de parte aérea y total (P ≤ 0,05). En calabacita, la mezcla con 16% de gallinaza incrementó área foliar (P ≤ 0,05). En las variables de altura, peso seco de raíz y balance de plántula no se encontraron diferencias significativas en ambas especies y mezclas. Se concluye que mezclas de turba europea (peat moss) con gallinaza o biosólido, son una importante alternativa técnica y económica para la producción de plántulas en pepino y calabacita

Enhanced Greenhouse Cooling Strategy with Natural Ventilation and Variable Fogging Rates

High-pressure fog (HPF) systems have advantages for greenhouse cooling compared to traditional systems, such as pad and fan. Such advantages include the potential of improving climate uniformity. Water is distributed throughout the greenhouse space thus reducing water use and energy operation costs, especially if used within naturally ventilated greenhouses. Fog cooling in combination with natural ventilation is difficult to manage, primarily because accurate estimation of air exchange rates is required to determine the precise amount of fog required. This limitation on automated control has been the main reason restricting the widespread commercial use of HPF systems. The goal of this research was to develop and implement a control strategy for a naturally ventilated greenhouse with a variable HPF system. The strategy that was developed included variable rate of fog introduced into the greenhouse, a dynamic control of the air ventilation openings, and it considered the contribution of cooling and humidification from the crop by evapotranspiration. Three evapotranspiration models, including Penman-Monteith, Stanghellini and Takakura, were calibrated and evaluated in terms of prediction accuracy. The Stanghellini model provided the best overall performance for several growing seasons and under two different evaporative cooling systems (i.e. pad and fan and natural ventilation with HPF), and was selected and implemented in the cooling control strategy. The strategy utilized enthalpy and vapor pressure deficit (VPD) of the greenhouse atmosphere for the control parameters. Using a calibrated greenhouse mechanistic climate model, a computer algorithm was created to simulate the capabilities of the proposed. The control strategy that was developed was able to maintain the greenhouse climate closer to the pre-established set points while consuming less water and energy, compared to a constant HPF system based on VPD control. Finally, the strategy was implemented in a single span research greenhouse. A four-day validation study provided good agreement for measured and simulated greenhouse climate values, as well as for water and energy use. Moreover, the strategy was able to maintain VPD around its set point for all the experiments and temperature remained around its set point when outside enthalpy was lower than the enthalpy set point

Thermal and ammonia concentration gradients in a rabbit barn with two ventilation system designs

ABSTRACT Rabbit barns are of economic importance in central Mexico, where rabbit breeders use rustic buildings for production. In such barns, climate conditioning is mostly based on natural ventilation (NV) where the lack of a well-designed NV system may be a limiting factor. In this study, computational fluid dynamics was used to analyse the performance of the NV system in a 24 x 4 x 4.8 m typical Central Mexico rabbit barn with a density of 20 rabbits m-2 of cage. The barn included both side vents at 1.2 m in height from the ground. Results indicated exchange rates of 0.052 and 2.9 x 10-4 m3 m-2 s-1 when the wind direction was simulated as orthogonal and parallel to the side vents, respectively, suggesting the orthogonal direction favoured the exchange rate. However, such conditions produced an accumulation of ammonia underneath the rabbit cages. Thus, a design modification including a lower inlet vent was analysed. Such modification substantially decreased the concentration gradients of temperature and ammonia

Modeling the Potential Distribution of Picea chihuahuana Martínez, an Endangered Species at the Sierra Madre Occidental, Mexico

Species distribution models (SDMs) help identify areas for the development of populations or communities to prevent extinctions, especially in the face of the global environmental change. This study modeled the potential distribution of the tree Picea chihuahuana Martínez, a species in danger of extinction, using the maximum entropy modeling method (MaxEnt) at three scales: local, state and national. We used a total of 38 presence data from the Sierra Madre Occidental. At the local scale, we compared MaxEnt with the reclassification and overlay method integrated in a geographic information system. MaxEnt generated maps with a high predictive capability (AUC > 0.97). The distribution of P. chihuahuana is defined by vegetation type and minimum temperature at national and state scales. At the local scale, both models calculated similar areas for the potential distribution of the species; the variables that better defined the species distribution were vegetation type, aspect and distance to water flows. Populations of P. chihuahuana have always been small, but our results show potential habitat greater than the area of the actual distribution. These results provide an insight into the availability of areas suitable for the species’ regeneration, possibly through assisted colonization