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Tópicos Sugeridos dentro de su búsqueda.
1
artículo
Publicado 2023
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The mechanics of unsatured soils are strongly related to the suction phenomenon that occurs between solid soil particles, which change when the water content of the soil does not remain constant. The soil-water characteristic curve (SWCC) provides information related to soil suction and water content; and to obtain said curve, different direct and indirect methods can be used. In this research, the soil-water characteristic curve for sand is obtained by implementing the filter paper test. For this, three reconstituted samples of sandy soils from Lima - Peru (relative density between 20% and 60%) were tested following the wet trajectory of the curve. Samples were stored for at least seven days until equilibrium was reached. In tihs way, discrete points of the soil-water characteristic curve were obtained. SWCC equations such as Brooks and Corey (1964), Van Genuchten (1980) and Frendlund a...
2
artículo
Publicado 2020
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Soil contamination by potentially toxic trace elements (PTEs) such as Cadmium (Cd), is a major environmental concern because of its potential implications to human health. Cacao-based products have been identified as food sources with relatively high Cd contents. Here, we assessed Cd concentrations of cacao-growing soils in four major agricultural regions with contrasting climates in Peru, one of the main exporters of cacao products worldwide. At each study site (n = 40) a broad range of potential factors affecting Cd concentration in soils, i.e., site, soil and management, were evaluated. Concentrations of Cd ranged between 1.1-3.2 mg kg-1. Mean values per region were below 2.7 mg kg-1, usually established as upper-limit for non-polluted soils. Cadmium concentrations were significantly (p < 0.001) higher in sites at higher elevations and in a temperate, drier climate. Cadmium correlated...
3
artículo
Publicado 2025
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La brecha de rendimiento del frijol común, una leguminosa altamente valorada en el oeste de Kenia, una región con alto potencial para este tipo de cultivos, se ha estado ampliando en tiempos recientes. Los bajos rendimientos del frijol común se atribuyen a las propiedades químicas del suelo, las enfermedades por pudrición de raíz y las prácticas agrícolas de los campesinos. Este estudio evaluó los indicadores de fertilidad para nutrientes del suelo antes de la siembra, los niveles de inóculo de pudrición de raíz y la respuesta consecuente del crecimiento del frijol común frente a dicha enfermedad, considerando además la preferencia varietal de los pequeños agricultores y la fuente de la semilla. Posteriormente se analizó el estado nutricional del suelo, se identificaron los patógenos del suelo más prevalentes y se realizaron experimentos de campo. El pH del suelo result...
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5
artículo
Publicado 2023
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Soil organic carbon (SOC) plays a crucial role in soil quality and nutrient availability. Agricultural practices, such as tillage and crop rotations, can affect SOC levels. Pitahaya cultivation, a growing crop in dry tropical environments regions may affect soil quality due to weed management. This study aims to assess the relationship between alternative crop management and pitahaya species on SOC sequestration. Two plots, each for yellow (Selenicereus megalanthus) and red (Hylocereus Undatus) pitahaya, were established. Rice husks were used as a natural mulch to prevent weed growth as a new control alternative. Soil sampling was conducted at different depths (0-5, 5-10, 10-20, and 20-30 cm) and locations (below plant vs row) within the pitahaya plots. The study found at the 0-5 cm section presents the highest concentration of organic carbon at 2.01%, 1.77%, and 1.97% below plant in red...
6
artículo
Publicado 2024
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This study presents a methodology that includes hydraulic and mechanical constitutive relationships for modeling the complex volumetric behavior of unsaturated soils. The mechanical relationships are based on the generalized effective stress concept, and the hydraulic relationships adopt soil water retention curves dependent on soil deformation. After the formulation and the introduction of the governing equations, a study case based on the results of suction-controlled oedometric tests is presented, aiming for a better understanding of the effect of compaction on unsaturated soils. The oedometric compression curves of a first set of laboratory tests are reinterpreted in terms of the generalized effective stress concept to obtain the required model parameters. Then, numerical simulations are performed to analyze the soil susceptibility to large volumetric strains triggered by a combined ...
7
artículo
Publicado 2018
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The type of soil and soil collapse potential of the Intiorko Health Post, district of Ciudad Nueva, department of Tacna, was investigated. Applied research was developed, due to the use of preexisting knowledge in research and technical standards, analyzing existing information close to the study area, developing standard tests for the identification of collapsible soils, as well as laboratory and in situ collapse tests. The load test with collapse of the soil structure to determine the potential for collapse. It was identified that the physical, mechanical and chemical properties contribute to the collapsible structure of the soil, this due to the low natural density, liquid limit, high ratio of voids and total soluble salts; Likewise, he identified that at the pressure of 1.00 kg / cm2 collapse problems are not generated, while with 2.00 kg / cm2 the problem is moderate; It was also id...
8
artículo
Peru is a country rich in natural resources, which is not at issue but when we seek the richness of the soil resource is found that the lowest in Latin America, the relationship between man and land in our country for food production is low and limited, located only in some regions, so it is necessary to develop a strategy for integrated management of land, which starts from the ground potential, its economic, environmental and social knowledge of the possibilities, from a proper zoning, economic and ecological, categorizing their relationship to occupancy to avoid a conflict of use or benefit to our country almost always ends in socio-environmental conflicts. For example, it has contaminated soils in La Oroya, which is now a matter of legal dispute will be environmental in the arbitration against the Peruvian government before the International Centre for Settlement of Inves-tment Dispu...
9
artículo
We present the information available on the phenomenon of soil liquefaction in Peru due to the seismic action and its representation in a map of soil liquefaction areas. The map of soil liquefaction areas is drawn to the scale 1: 5'000,000 and presents distinctions between liquefaction and probable liquefaction cases, according to the interpretation of the information available in the literature. All the documentation that presents evidence of the phenomenon of liquefaction, such as the formation of small volcanoes of mud and sand, the violent expulsion of water from the soil, the presence of intense cracking and the differential settlements due to the seismic action, has been detailed in this article.
10
artículo
We present the information available on the phenomenon of soil liquefaction in Peru due to the seismic action and its representation in a map of soil liquefaction areas. The map of soil liquefaction areas is drawn to the scale 1: 5'000,000 and presents distinctions between liquefaction and probable liquefaction cases, according to the interpretation of the information available in the literature. All the documentation that presents evidence of the phenomenon of liquefaction, such as the formation of small volcanoes of mud and sand, the violent expulsion of water from the soil, the presence of intense cracking and the differential settlements due to the seismic action, has been detailed in this article.
11
artículo
Publicado 2023
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The objective of this study was to analyze the relationships between the Visual Evaluation of Soil Structure (VESS) and soil properties that make its adoption widely used in agriculture. For this, 25 papers related to the VESS (2009-2022) were considered where the information of the authors, the soil property: bulk density (BD), total soil porosity (TP), soil penetration resistance (PR), macroporosity, microporosity, soil organic carbon (SOC), and mean weight diameter of stable aggregates (MWD). The sample size (n=120 cases), and the correlation coefficient were extracted. To measure this relationship, the correlation coefficient of all studies was contemplated. A meta-analysis was carried out to obtain a global measure of the correlation between the VESS and soil properties across the studies. In the first instance, a fixed effects model was fitted for the correlation (effect size, know...
12
artículo
Publicado 2021
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Biochar is a product that is obtained from different types of biomass such as pine wood bark, bamboo, organic and vegetable waste, human manure, poultry manure, among others. Biochar has been used in different ways as a soil improver among which are: improving the retention of water and nutrients in the soil, increasing the productivity of crops, increasing the quality of the soil and also acting as a sequestrant of carbon dioxide. This use as a soil improver is not only recognized from a research or academic point of view, but there is a lot of business interest in its development and commercialization, which is seen by the accelerated trend of patent research and development in the last ten years. Technology leadership is represented by US companies and the academic sector by Chinese universities publications. The future of biochar, as a soil conditioner, looks promising from both a bu...
13
artículo
Publicado 2021
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Biochar is a product that is obtained from different types of biomass such as pine wood bark, bamboo, organic and vegetable waste, human manure, poultry manure, among others. Biochar has been used in different ways as a soil improver among which are: improving the retention of water and nutrients in the soil, increasing the productivity of crops, increasing the quality of the soil and also acting as a sequestrant of carbon dioxide. This use as a soil improver is not only recognized from a research or academic point of view, but there is a lot of business interest in its development and commercialization, which is seen by the accelerated trend of patent research and development in the last ten years. Technology leadership is represented by US companies and the academic sector by Chinese universities publications. The future of biochar, as a soil conditioner, looks promising from both a bu...
14
artículo
The polyhydroxyalkanoates (PHA) are considered as source of renewable-resource-based, biodegradable materials and plastics of a wide range industrial uses, but high production costs impede large-scale implementa- tion. In this paper, we induced the production of polyhydroxyalkanoates (PHA) in actinomycetes isolated from Colombian soil, the microorganism with highest production and accumulation of biopolymer was isolated and identified. With Nile blue dye, we determined in three of the ten strains isolated, the presence of intracellular fluorescent granules type polyhydroxyalkanoate. The three strains were cultured for obtained significant amounts of PHA. The strain named 7F had the highest production. After purification, identification and quantification we determined a yield of 27.48% in dry weight, which means a good productivity. This strain was identified as Streptomyces subrutilus, ...
15
artículo
Publicado 2017
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The objective of this research was to evaluate extraction methods for β-glucosidases comparing three buffer solutions (MUB, acetate, and maleate) at different incubation times (0.5 h to 10 h) and in three different soil orders (Mollisols, Andisols and Ultisols). Seven acidic soils were evaluated, showing differences in pH, OM, and clay contents. To evaluate the effect of OM as enzymes source, one soil of each order was treated to partially remove its OM and then the enzyme assay was performed. When using MUB and maleate buffers the highest (32 and 31 µg-pNP g-soil-1h-1 in average, respectively) were found, and the latter was significantly (p < 0.050) correlated with the soil clay content. The activity obtained with acetate buffer was much lower (38.2 µg-pNP g-soil-1h-1 in average). The use of MUB buffer with 1 h of incubation is suggested as extraction method, showing good reprod...
16
artículo
Publicado 2017
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The objective of this research was to evaluate extraction methods for β-glucosidases comparing three buffer solutions (MUB, acetate, and maleate) at different incubation times (0.5 h to 10 h) and in three different soil orders (Mollisols, Andisols and Ultisols). Seven acidic soils were evaluated, showing differences in pH, OM, and clay contents. To evaluate the effect of OM as enzymes source, one soil of each order was treated to partially remove its OM and then the enzyme assay was performed. When using MUB and maleate buffers the highest (32 and 31 µg-pNP g-soil-1h-1 in average, respectively) were found, and the latter was significantly (p < 0.050) correlated with the soil clay content. The activity obtained with acetate buffer was much lower (38.2 µg-pNP g-soil-1h-1 in average). The use of MUB buffer with 1 h of incubation is suggested as extraction method, showing good reprod...
17
artículo
Carabayllo, district of North Lima, in the last decades, has experienced a substantial loss of periurban agricultural land due to the development of real estate programs, process with repercussions in the lifestyle, social relations, as well as in the forms and mechanisms of possession space.This article, in a synoptic and specific way, and based on data collected in field work, has the purpose of analyzing the processes of periurbanization and differentiation produced by the urban land market in Punchauca, one of the populated centers of Carabayllo.
18
artículo
This article addresses in detail the geotechnical characterization of fine soils in the city of Pucallpa, in the Amazon region of Peru. With the main objective of describing the mechanical behavior and the very particular physical characteristics of these fine clay-type soils in the areas of Yarinacocha, Manantay and Callería, for this purpose, a geotechnical campaign was carried out that consisted of the execution of 40 manual excavations of the open-air pit type with depths of up to 1.50 meters, with the purpose of recovering unaltered samples in the form of cubes of 0.40 m on each side, for subsequent transfer to the soil mechanics laboratory of the Ricardo Palma University, where they were They carried out normal and special tests to obtain their physical and mechanical characteristics. The samples are characterized by the predominance of fine clay-type particles of high and low pla...
19
tesis doctoral
Publicado 1977
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Descargue el texto completo en el repositorio institucional del Massachusetts Institute of Technology: http://hdl.handle.net/1721.1/111040
20
artículo
Publicado 2017
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The present trial was carried with the aim to evaluate the effect of a soils bioenhancer and organic fertilizers on the physical and chemical component of quality soil in onion in Majes Irrigation. The trial was carried out in a plot under spray irrigation and splot under drip irrigation, in both plot was stablished the sources and levels from organic fertilizer (Chicken manure and seabird guano) compared against chemical fertilization. A completely random block design was used with 9 treatments and 3 repetitions for each plot, after that it was made a combined analysis to both plots. Effective deep roots and average infiltration speed were evaluated like physical indices of quality soils. The electric conductivity, pH, CaCO3 (%), organic matter (%) phosphorus (ppm), potassium (ppm), cation exchange capacity and exchangeable cations (Ca, Mg, Na y K), were evaluated like chemical indices ...
