1,720,958 research outputs found
Stock de carbono en suelos antrópicos de bosques secundarios en la amazonia central brasilera
No full textIn the Brazilian central Amazon, there are anthropic soils popularly known in the native language as “Terra Preta de Indio” (Dark earth) that present a dark colored soil profile that generally presents high natural fertility as a characteristic, with high concentrations of P, Ca, Mg, Zn and organic matter. As in general, they present high levels of C, with concentrations up to 150 g C kg¯1, the capacity of anthropic soils to store C is stable at high levels, being an important mechanism to reduce the “greenhouse effect” that needs to be further evaluated and understood. This study has the objective to determine the stock of C in the anthropic and adjacent soils under secondary forests of the central Brazilian Amazon. From where we opened pit and collected undisturbed samples of the three types of soils studied, where we analyzed the concentrations of C with which we calculated the Stokes of C, as well as the physical and chemical properties of these soils. Hence, we found that the TPI in the EA area has a greater stock of C than SA, with values of 204.9 and 176.5 Mg C ha-1 respectively, but there is no significant difference. The Stokes are smaller in the other TPIs in other areas. For which we conclude that the greater stock of C found in the SA is due to the difference that it has in its concentration of clay, being greater when compared to the TPI. The concentration of clay in the soil is related to the concentration of C in the soil.En la Amazonia central brasilera ocurren suelos antrópicos conocidos popularmente en su lengua nativa como “Terra Preta de Indio” (TPI) que presentan un perfil del suelo de color oscuro que generalmente presenta alta fertilidad natural como característica, con elevadas concentraciones de P, Ca, Mg, Zn y de materia orgánica. Así como en general presentan niveles elevados de C, con concentraciones hasta de 150 g C kg¯1, la capacidad de los suelos antrópicos de almacenar C estable es altos, siendo un importante mecanismo para disminuir el efecto “Invernadero” que necesita ser mejor evaluada y entendida. Este estudio tuvo como objetivo determinar el stock de C en los suelos antrópicos y adyacentes bajo bosques secundarios de la Amazonia central brasilera. Donde fueron abiertos calicatas y colectadas muestras indeformadas de los tres tipos de suelos estudiados donde analizamos las concentraciones de C con las cual calculamos los Stokes de C, así como analizamos sus propiedades físicas y químicas de estos suelos. Donde encontramos que la TPI del área de EA tiene mayor stock de C que los SA, con valores de 204.9 y 176.5 Mg C ha-1 respectivamente, pero sin diferencia significativa. Los Stokes son menores en los demás TPI de las otras áreas. Por la cual concluimos que el mayor stock de C encontrados en los SA es por la diferencia que tiene en su concentración de arcilla, siendo mayores cuando comparadas a las TPI. Ya que la concentración de arcilla del suelo está relacionada a la concentración de C del suelo
Métodos de labranza en las características agronómicas de Brassica napus L. Nabo var. Minowase. Loreto 2023
Get PDFTillage are activities that, over time, form the ideal soil in order to ideal soil in order to allow the root system to explore the largest volume of soil and to to explore the largest volume of soil and absorb the available nutrients. The objective of this study was to evaluate the effect of tillage types on agronomic tillage types on the agronomic characteristics and yield of Brassica napus L. Nabo var. Minowase. Loreto 2023. The study was conducted at the Faculty of Agronomy-UNAP, Horticultural Plants Workshop. A completely randomized block design was used (DBCA) with 2 treatments (T0: manual tillage and T1: mechanical tillage). and T1: mechanized tillage) with 12 replications. The main conclusions were that the main conclusions were that the agronomic characteristic of plant extension did show significant differences significant differences between soil tillage types., which meant a greater leaf area to capture more solar energy and accumulation of reserves, the root diameter and length characteristics did present significant differences between soil tillage types, but contrary, since the diameter was greater and lesser in length in manual tillage, respectively, and in mechanized tillage the diameter was lesser and greater in length, respectively, the aerial part (leaf weight) was lesser in manual tillage (50. 64 g) than in mechanized tillage (61.67 g), root weight, actual and potential yield showed the highest results with manual tillage (142.2 g, 24,923 kg ha-1 and 35,604 kg ha-1), mechanized tillage is not always synonymous with crop yield.La labranza son actividades que mediante el tiempo forman el suelo ideal con la finalidad de permitir que el sistema radicular explore el mayor volumen de suelo y absorber los nutrientes disponibles. El objetivo de este estudio fue evaluar el efecto de los tipos de labranza sobre las características agronómicas y el rendimiento de Brassica napus L. Nabo var. Minowase. Loreto 2023. El estudio fue realizado en la Facultad de Agronomía-UNAP, Taller de Plantas Hortícolas. Fue utilizado un diseño de bloques completamente al azar (DBCA) con 2 tratamientos (T0: labranza manual y T1: labranza mecanizada) con 12 repeticiones. Las principales conclusiones fueron que las característica agronómica de extensión de planta si presentó diferencias significativas entre los tipos de labranza del suelo, lo que significó una mayor área foliar para captar mayor energía solar y acumulación de reservas, las características diámetro y longitud de raíz si presentaron diferencias significativas entre los tipos de labranza del suelo, pero contrarias, ya que el diámetro fue mayor y menor en longitud en la labranza manual, respectivamente, y en la labranza mecanizada el diámetro fue menor y mayor en longitud, respectivamente, la parte aérea (peso de hojas) fue menor en la labranza manual (50.64 g) que en la mecanizada (61.67 g), el peso de raíz, rendimiento real y potencial presentaron los mayores resultados con la labranza manual (142.2 g, 24,923 kg ha-1 y 35,604 kg ha-1), la labranza mecanizada no siempre es sinónimo de rendimiento en el cultivo
Distanciamientos de siembra y su relación con las características agronómicas y rendimiento de Momordica charantia L. “balsamina”, en Zungarococha, Loreto.2019
Get PDFEl trabajo de investigación se desarrolló en el Taller de Enseñanza e Investigación
de Plantas Hortícolas de la Facultad de Agronomía-UNAP, ubicada en el Km 3
carretera Zungarococha, al Sur de la ciudad de Iquitos, Distrito de San Juan
Bautista,cuyas coordenadas geográficas son: Latitud Sur 03º 46´ 13.2´´; Longitud
Oeste 73º 22´ 10.4´; Altitud: 126 msnm. El nivel de investigación fue explicativo
con una variable independiente (distanciamiento de siembra) y seis variables
dependientes (Numero de frutos/planta, largo de fruto, diámetro de fruto, peso de
fruto, numero de frutos/planta y peso de frutos/planta. El objetivo general fue
determinar la relación de los distanciamientos de siembra con las características
agronómicas y rendimiento de Momordica charantia L. “balsamina”, en
Zungarococha, Loreto.2019. El Diseño experimental que se empleo fue el de
Bloques Completamente al Azar, con cuatro tratamientos y cuatro repeticiones.
Cada unidad experimental estuvo constituida de 2 filas, 4 plantas/fila y la unidad
de muestreo estuvo constituida por cuatro plantas/unidad experimental. Los
resultados demuestran, con relación al número de frutos/planta, que el T1 (1.5 m
x 1 m.) presento el mayor número de frutos (24) y tuvo significancia estadística
que los demás tratamientos estudiados; con respecto al largo de fruto, el T4 (3 m.
x 1 m.), presento el valor más alto con 31 cm. superando con significancia
estadística a los demás tratamientos; en relación al diámetro de fruto los
resultados obtenidos no tuvieron significancia estadística entre los tratamientos;
en cuanto al peso de fruto, el T4 con 363 g. supero significativamente a los demás
tratamientos estudiados; con respecto al peso de frutos/planta, el T1 alcanzo una
media de 7,176 g. superando significativamente a los demás tratamientos y en
relación al peso de frutos/ha, el T1 con 28,704 Kg/ha tuvo el mayor rendimiento
de peso de frutos/ha, superando estadísticamente en forma significativa a los
demás tratamientos estudiados.The research work was developed in the Horticultural Plant Teaching and
Research Workshop of the Faculty of Agronomy-UNAP, located at Km 3
Zungarococha highway, south of the city of Iquitos, District of San Juan Bautista,
whose geographical coordinates are : South Latitude 03º 46´ 13.2´´; West
Longitude 73º 22´ 10.4´; Altitude: 126 meters above sea level. The research level
was explanatory with an independent variable (planting spacing) and six
dependent variables (Number of fruits / plant, length of fruit, diameter of fruit,
weight of fruit, number of fruits / plant and weight of fruits / plant. The general
objective was to determine the relationship of the planting distances with the
agronomic characteristics and yield of Momordica charantia L. “balsamina”, in
Zungarococha, Loreto. 2019. The experimental design that was used was that of
Completely Random Blocks, with four treatments and four replications. Each
experimental unit consisted of 2 rows, 4 plants / row and the sampling unit
consisted of four plants / experimental unit. The results show, in relation to the
number of fruits / plant, that T1 (1.5 mx 1 m.) presented the highest number of fruits
(24) and had statistical significance than the other treatments studied; with respect
to fruit length, T4 (3 m. x 1 m.), presented nto the highest value with 31 cm.
surpassing with statistical significance the other treatments; Regarding the
diameter of the fruit, the results obtained did not have statistical significance
between the treatments; Regarding the weight of fruit, the T4 with 363 g. it
significantly outperformed the other treatments studied; Regarding the weight of
fruits / plant, T1 reached an average of 7.176 g. significantly exceeding the other
treatments and in relation to the weight of fruits / ha, the T1 with 28,704 Kg / ha
had the highest yield of fruit weight / ha, statistically significantly exceeding the
other treatments studied
Dosis de gallinaza en el aporque en las características agronómicas y rendimiento en Lactuca sativa L., Var. great lakes. Loreto. 2023
No full textThe hilling is a cultural task that is performed in many cultivated plants and consists of accumulating soil at the foot of the plant, mainly to provide greater stability, control pests, diseases and maintain greater soil moisture. Along with this work, in some crops such as lettuce, fertilization is used to improve yields. The objective of this study was to evaluate the effect of different levels of organic fertilizer applied in the hilling on the agronomic characteristics and yield of Lactuca sativa L., var. Great Lakes in Zungaro Cocha, San Juan - 2023. The study was conducted at the Horticultural Plants Workshop, Faculty of Agronomy-UNAP. A completely randomized block design (CRBD) was used with 4 treatments consisting of different doses of poultry manure (T0: 0, T1: 1, T2: 2, T3: 3 kg.m-2) at the time of hilling and with 4 replications. American lettuce variety Great Lakes was used. After analysis of the results, the main conclusions were that the different doses of poultry manure applied at the time of hilling did not significantly influence the agronomic characteristics of plant height, plant extension, head diameter and head height. However, there were significant differences for root mass, stem mass, head mass and total plant mass. With the T3 treatment (3 kg.m-2), lower root mass (6.16 g) and higher stem mass (38.89 g), head/plant mass (349.16 g) and total plant mass (394.25 g) were obtained. It also allowed estimating the maximum yield at 39,106 kg.ha-1 of heads of American lettuce var. Great Lakes. For each kg of poultry manure applied at the time of hilling, there is an increase of 29.7 g of head/plant mass.El aporque es una labor cultural que se realiza en muchas plantas cultivadas y que consiste en acumular tierra al pie de la planta, para dar principalmente mayor estabilidad, controlar plagas, enfermedades y mantener mayor humedad en el suelo. Junto con esta labor, en algunos cultivos como la lechuga se aprovecha para realizar el abonamiento con el fin de mejorar los rendimientos. El objetivo de este estudio fue evaluar el efecto de los diferentes niveles de abono orgánico aplicados en el aporque sobre las características agronómicas y el rendimiento de Lactuca sativa L., var. Great Lakes en Zungaro Cocha, San Juan – 2023. El estudio se realizó en el Taller de Plantas Hortícolas, de la Facultad de Agronomía-UNAP. Se utilizó un diseño de bloques completamente al azar (DBCA) con 4 tratamientos que consistían de diferentes dosis de gallinaza (T0: 0, T1: 1, T2: 2, T3: 3 kg.m-2) al momento del aporque y con 4 repeticiones. Se utilizó la lechuga americana variedad Great Lakes. Después del análisis de los resultados, las principales conclusiones fueron que las diferentes dosis de gallinaza aplicadas al momento del aporque no influenciaron significativamente las características agronómicas de altura de planta, extensión de planta, diámetro de cabeza y altura de cabeza. Entretanto, si tuvieron diferencias significativas para masa de raíz, masa de tallo, masa de cabeza y masa total de planta. Con el tratamiento T3 (3 kg.m-2) se obtuvieron menor masa de raíz (6,16 g) y mayor masa de tallos, con 38.89 g; masa de cabeza/planta, con 349.16 g y masa total de planta, con 394.25 g. Asi mismo permitió estimar el rendimiento máximo en 39,106 kg.ha-1 de cabezas de lechuga americana var. Great Lakes. Por cada kg de gallinaza aplicado al momento del aporque, hay un incremento de 29.7 g de masa de cabeza/planta
Caracterización física y química del suelo con diferentes edades de reforestación en el Sur Oeste de la Amazonia Brasilera
Get PDFEl área en estudio forma parte del complejo petrolífero de la Base de Operaciones Geólogo Pedro de Moura (BOGPM), explotada por PETROBRAS en el sur oeste de la amazonia brasilera, localizadas en áreas de bosque primario, ubicado a 660 km de la ciudad de Manaos, Brasil, con el objetivo de evaluar las características físicas y químicas del suelo en áreas con diferentes edades de reforestación y en bosque primario.
La metodología de la investigación que se empleó fue el Diseño Completo al Azar (DCA), con cuatro (04) tratamientos y quince (15) repeticiones.
Los resultados del estudio de las características físicas y químicas del suelo de las áreas reforestadas y del bosque primario, fueron sometidos a un análisis de normalidad y homogeneidad. Las características físicas y químicas que presentaron normalidad y homogeneidad fueron sometidas al análisis de variancia.
Se concluye que, en relación a las características físicas del suelo, estas fueron influenciadas por las diferentes edades de reforestación. Todas las características químicas del suelo fueron influenciadas por las diferentes edades de reforestación, con excepción del fosforo. Las características físicas y químicas del suelo de las áreas en estudio fueron alteradas con la retirada del bosque primario y del horizonte superficial del suelo. Se observa que los 10 primeros cm del suelo de las áreas reforestadas presentan una lenta recuperación de algunas características físicas y químicas.The study area is part of the oil complex the Base of Operations Geologist Pedro Moura (BOGPM), operated by Petrobras in the south west of the Brazilian Amazon, located in areas of primary forest, located 660 km from the city of Manaus, Brazil, with the objective to evaluate the physical and chemical characteristics of soil in areas with different ages of reforestation and primary forest.
The research methodology used was the complete design at random, with four treatments (04) and fifteen (15) repetitions. The results of the study of the physical and chemical characteristics of the soil of the reforested areas and of primary forest, were subjected to an analysis of normality and homogeneity. The physical and chemical characteristics that presented normality and homogeneity were subjected to analysis of variance.
It is concluded that, in relation to the physical characteristics of the soil, these were influenced by the different ages of reforestation. All the chemical characteristics of the soil were influenced by the different ages of reforestation, with the exception of phosphorus. The physical and chemical characteristics of the soil in areas under study were altered with the removal of the primary forest and the horizon surface layer. It is noted that the first 10 cm from the floor of the reforested areas have a slow recovery of some physical and chemical characteristics.A área de estudo é parte do complexo de óleo a Base de Operações Geólogo Pedro de Moura, operado pela Petrobras no sudoeste da Amazônia brasileira, localizado em áreas de floresta primária, localizado a 660 km da cidade de Manaus, Brasil, com o objetivo de avaliar as características físicas e químicas do solo em áreas com diferentes idades de reflorestamento e floresta primária.
A metodologia utilizada foi o design completo ao acaso, com quatro tratamentos (04) e quinze (15) repetições. Os resultados do estudo das características físicas e químicas dos solos das áreas reflorestadas e de floresta primária, foram sujeitos a uma análise de normalidade e homogeneidade. As características físicas e químicas que apresentaram normalidade e homogeneidade foram submetidos à análise de variância.
Conclui-se que, em relação às características físicas do solo, estes foram influenciados pelas diferentes idades de reflorestamento. Todas as características químicas do solo foram influenciadas pelas diferentes idades de reflorestamento, com exceção do fósforo. As características físicas e químicas do solo em áreas sob estudo foram alteradas com a remoção da floresta primária e o horizonte camada superficial. É de notar que os primeiros 10 cm do piso das áreas reflorestadas têm uma lenta recuperação de algumas características físicas e químicas.Tesi
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
