Lake Texcoco Research Articles

Probability of Heavy Metals Mobility from Dumped Sediments in a Quarry

Dregs from the former Texcoco Lake were used to build the new international Mexico City airport and pumped in a quarry. The dredged sediments could have heavy metals (HMs) capable of polluting water bodies. The study’s objective was to evaluate the content of Cu, Zn, Cd, Ni, and Pb of the sediments deposited in the quarry, their transfer to the runoff water and the adsorption of Cu, Zn, Ni, and Pb in the subsoil. Other variables measured were water infiltration rate, HM in sediments, water runoff, and the HM adsorption in the subsoil. The infiltration rate in sediments is low (≤ 10-7 cm/h). HMs in sediments are within the maximum permissible limits by Mexican regulations, for sewage sludge. The HMs in the runoff from the sediments are in the range of the Mexican regulations for the discharge into rivers and for irrigation purposes of agricultural soils. They are also within safe limits for irrigation use considered by FAO and EPA. The materials adsorption capacity of Pb (1250 mg kg-1), Zn (588 mg kg-1), and Cu (1250 mg kg-1) is higher than the concentration of metals in the runoff water, so the movement of HMs down into the subsoil is unlikely.

Bacterial Communities in Alkaline Saline Soils Amended with Young Maize Plants or Its (Hemi)Cellulose Fraction.

We studied three soils of the former lake Texcoco with different electrolytic conductivity (1.9 dS m−1, 17.3 dS m−1, and 33.4 dS m−1) and pH (9.3, 10.4, and 10.3) amended with young maize plants and their neutral detergent fibre (NDF) fraction and aerobically incubated in the laboratory for 14 days while the soil bacterial community structure was monitored by means of 454-pyrosequencing of their 16S rRNA marker gene. We identified specific bacterial groups that showed adaptability to soil salinity, i.e., Prauseria in soil amended with young maize plants and Marinobacter in soil amended with NDF. An increase in soil salinity (17.3 dS m−1, 33.4 dS m−1) showed more bacterial genera enriched than soil with low salinity (1.9 dS m−1). Functional prediction showed that members of Alfa-, Gamma-, and Deltaproteobacteria, which are known to adapt to extreme conditions, such as salinity and low nutrient soil content, were involved in the lignocellulose degradation, e.g., Marinimicrobium and Pseudomonas as cellulose degraders, and Halomonas and Methylobacterium as lignin degraders. This research showed that the taxonomic annotation and their functional prediction both highlighted keystone bacterial groups with the ability to degrade complex C-compounds, such as lignin and (hemi)cellulose, in the extreme saline-alkaline soil of the former Lake of Texcoco.

Trashing Scale

This article provides a conceptual and historical approach to frame the recurrent use of animism in contemporary art and theory. It calls attention to the ‘anthropological turn’ that took place in the 1980–1990s that characterised objects and artworks as agents, and revise the notion of the ‘socialist object’ to define the kind of agency commodities have achieved in late capitalism. It argues that the current interest in new forms of agency can be related to an animistic object resulting from the overlapping of flexible commodities and diffuse things: garbage. Pollution and waste are generating unpredictable kinds of agency that are engulfing humans in unprecedented assemblages. The article specifically focuses on how two artistic projects – Adriana Salazar’s The Animistic Museum of Texcoco Lake (2018) and TRES art collective’s Ubiquitous Trash (2016) – engage with different notions of animism and trash in their devising of experimental post-humanist scales.

LACUSTRINE DYNAMICS AND TLATEL-TYPE SETTLEMENTS FROM MIDDLE FORMATIVE TO LATE AZTEC IN THE EASTERN PART OF LAKE TEXCOCO, MEXICO

AbstractIn the territories of the former lakes in the Basin of Mexico, a tlatel was an insular settlement associated with the exploitation of lacustrine resources. This study examines the stratigraphy and geomorphological context of three tlateles in the eastern part of the former Lake Texcoco and correlates their phases of development with regional paleoclimatic trends from the seventh century b.c. to the sixteenth century. The results of this research indicate that fluvio-lacustrine (i.e., deltaic) sedimentation and freshwater springs in the lake basin were important features for the establishment of tlatel settlements in the highly dynamic and saline lacustrine environment. The formation and abandonment of the studied tlateles correlate with changes in other settlements and developments recorded in other parts of Lake Texcoco. Sites and sediments in the eastern part of Lake Texcoco provide proxy information on the lacustrine changes that accompanied the development of Tenochtitlan and other lacustrine settlements in its western part.

Diversity of amoA and pmoA Genes in Extremely Saline Alkaline Soils of the Former Lake Texcoco

Ammonia-oxidizing bacteria (AOB) and aerobic methane oxidizing-bacteria (MOB) were studied in three extreme soils of the former Lake Texcoco, Mexico, with pH ranging from 8.5 to 10.5 and electrolytic conductivity (EC) from 0.67 to 84.76 dS m−1, and in two arable soils. Soil DNA was extracted with three different methods and total DNA was used as a template to amplify the pmoA and amoA functional genes and subsequently sequenced by pyrosequencing. The amoA gene sequences clustered as uncultured AOB dominated in the Texcoco soils, while Nitrosospira was dominant in the arable soils. Sequences of MOB associated with Nitrosococcus-rel (Type I) dominated (>85%) in the Texcoco soils, but they were more diverse in the arable soils, for example, JR2, JR3, Methylocaldum USC-g (Type I), USC-a (Type II) and gp23 (pxmA). Aerobic methane oxidizing-bacteria and AOB microbial diversity were significantly related to EC and pH (p < 0.05). As such, the lower MOB and AOB microbial diversity in the Texcoco soil compared to the arable soil was determined by its higher EC and pH.

Proyectos y obras para el uso de los terrenos desecados del antiguo lago de Texcoco, 1912-1998

&lt;p&gt;El presente trabajo examina las ideas acerca del posible uso de la tierra descubierta debido a la desecación del lago de Texcoco, producto del Desagüe del Valle de México. El texto explica la variedad de ideas propuestas por ingenieros y otros expertos, muchos de los cuales imaginaron un espacio de múltiples usos, con fines agrícolas, silvícolas, recreativos y ecológicos. La aportación de esta investigación consiste en mostrar cómo y por qué esos planes e ideas cambiaron a lo largo del siglo XX. Los resultados muestran que la transformación de su aspecto y naturaleza ha sido un anhelo constante, limitado por las especiales condiciones del subsuelo. Para la realización de esta investigación se consultó un gran número de fuentes escritas y se acudió al Archivo Histórico y Biblioteca Central del Agua y al Museo Archivo de la Fotografía.&lt;/p&gt;

Exoenzyme-producing halophilic bacteria from the former Lake Texcoco: identification and production of n-butyl oleate and bioactive peptides

Halophilic bacterias from saline soil from former Lake Texcoco were isolated, identified based on 16 rRNA and tested to produce glucolytic, nucleolytic, proteolytic and lipolytic exoenzymes. The Bacillus, Virgibacillus, Kocuria, Salinicoccus, Gracilibacillus, Halobacillus, Tenuibacillus and Nesterekonia genera where identified. Lipase/eserases and proteases from Nesterenkonia sp. and Nesterenkonia aethiopica showed halotolerant characteristics and were selected to synthesize the oleochemical n-butyl oleate and antioxidant peptides from muscle protein of common carp (Cyprinus carpio), respectively. In organic media (2,2,4-Trimethylpentane), the lipase/esterases from Nesterenkonia sp. (0.6U/mL) and N. aethiopica (1.2U/mL) achieved a 62.7% and 53.2% of n-butyl oleate conversion, respectively. The protein hydrolysis from muscle of common carp (C. carpio) showed a degree of hydrolysis of 4.5 ± 0.2% and 2.8 ± 0.1% when proteases from Nesterenkonia sp. and N. aethiopica were used, respectively. Three peptidic fractions ranging molecular masses between 254 and 1002Da [M + H] show antioxidant scavenging activity, and the principal fraction with a peptide of 547.3Da [M + H] showed an inhibition of 37.7 ± 1.8% and 16.3 ± 0.6%, when 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were used, respectively. These findings showed that the enzymatic battery of the halophilic bacteria from former lake Texcoco can be used in hydrolysis and synthesis of molecules with applications in different fields as food technology or bioenergy.

Assessment of metal contamination and their ecological risks in wetland sediments of the former Texcoco saline lake, Mexico

Texcoco saline lake in Mexico is an important habitat for over 300 species and recharges the Mexico City aquifer. Presently, it is on the verge of disappearance due to increasing anthropogenic pressure and comprises only a few wetland remnants. The impacts of human activities on these wetlands are unknown and uninvestigated. In this regard, this study investigates the degree of metal contamination in this ecosystem during the period of 2015–2018. Twenty-six sediment samples were collected from nine different wetlands of Texcoco Lake and examined for 17 metals (Al, Fe, Ca, Mg, Na, K, As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Hg) using atomic absorption spectroscopy. The degree of metal accumulation and its ecological risks were evaluated on the basis of several indicators (geoaccumulation index, enrichment factor, sediment quality guidelines, ecotoxicological values, and potential ecological risk index). Furthermore, co-occurrence via multivariate statistical techniques was employed using the measured metal concentrations to identify their possible sources. The Cd, Cu, Pb, Zn, and Hg sediment concentrations were higher in magnitude than the background North American shale composite values, suggesting their external origin in all studied sediments. According to the calculated enrichment factors and geoaccumulation index, the sediments were mostly contaminated with Cd and Hg. The sediment quality guidelines and ecotoxicological values together with the ecological risk index suggested probable adverse biological effects due to the presence of Cr, Cu, Ni, and Hg. Cadmium and Hg accounted for nearly 51 and 45% of the ecological threat in the sediments. Based on the knowledge about metal levels and co-occurrence in different matrices and the multivariate data analyses of the detected metal concentrations, we infer that the main sources of metals are as follows: (1) Solonchaks and Vertisol soil types (Ca, Mg, Na, and K); (2) urban-industrial effluents from surrounding municipalities and Mexico City (Cu, Pb, and Zn); and (3) industrial discharges of Xalostoc zone (Cd and Hg) near Texcoco. Our results emphasize the impacts of unregulated discharges from municipal, industrial, and metropolitan zones of Mexico City and construction activities for the elevated metal concentrations in the wetland sediments of Texcoco Lake.

Regional subsidence at the former Texcoco Lake: numerical modelling and settlements prediction

Abstract. This paper describes the application of an EVP one-dimensional constitutive soil model to analyse regional subsidence. The model was modified assuming that the boundary conditions vary over time, as well as considering the stratification of the subsoil. It adequately simulates the consolidation process caused by the exploitation of the aquifers that underlie the Mexico basin, and is validated at a site in the former Texcoco Lake, some 14 km north of Mexico City, where geotechnical and piezometric information is available together with records of past subsidence. Settlement predictions were carried out for different periods of time, assuming that pore pressure depletion rates at the permeable borders of the compressible strata remain constant over time.

Anisotropy of lacustrine soils in a large oedometer equipped with bender elements

Lacustrine soils from the former Texcoco Lake within the Basin of Mexico, some 14 km north of Mexico City, have unique geotechnical properties. These materials have been thoroughly studied in the past, and yet, very few investigations have addressed the issue of the anisotropy of their shear stiffness modulus at very small strain levels (G0). Stiffness anisotropy, even at very small deformations, may significantly influence the response of the soil in a variety of cases and applications including soil-structure interaction problems under static and dynamic conditions. In this study, a large-size oedometer equipped with bender elements was used to measure the shear wave velocities along different paths as an indirect assessment of G0. The initial or inherent anisotropy of the materials was evaluated with these measurements. The experimental results revealed that the stress-induced anisotropy was not significant; hence, the shear stiffness modulus was seen to depend mainly on the initial anisotropy. An inverse correlation between the yield stress (σ’y) (or over-consolidation ratio, OCR) and the initial anisotropy was found, whereas a direct correlation between the liquidity index and the initial anisotropy was also disclosed.

The Development of Air Pollution in Mexico City

The present essay documents changes to both objects of inquiry and the meaning of the epistemological concept of air pollution and it explains the processes that produced them. Smog as a result of production processes and the use of the automobile was not a concern for researchers and government managers in Mexico City, who were used to the dust storms resulting from the desiccation of the great Texcoco Lake during much of the 20th century, until the most industrialized nations of the West and the World Health Organization (WHO), alongside other international bodies such as the Organization for European Economic Cooperation (OEEC), reframed what was understood as air pollution, between the end of the 1960s and the beginning of the 1970s. Concerns about dust storms were displaced by concerns about factory and automotive emissions that contained new dangers—invisible hazards, just then being estimated, which altered what was understood or considered air pollution and gave rise to the quantification of particulate matter (which was then known as suspended dust particles) and new practices such as atmospheric monitoring. This essay concludes that what is understood as air pollution is situated; its meaning is not finite but simply evolves with time and with the rise of new global risks and concerns.

Life Above, Rubble Below: A Case of Historically Produced Risk &amp; Perception in Mexico City

Mexico City’s periphery is home to marginalized communities, and mainly constituted of autoconstructed houses built along the dried lakebed of Lake Texcoco. These settlements are subjected to amplified earthquake risk because of below-ground soil conditions in the lakebed beneath them, which makes them an ideal place to study the social production of risk. In Colonia del Mar, Tláhuac, people believe their community is built atop rubble dumped there after the 1985 earthquake. It is said the government illegally dumped debris from collapsed structures into the lakebed swamp that would be urbanized as Colonia del Mar. In 2017, another major earthquake caused structural collapses and damage along the lakebed edge, and especially in Colonia del Mar. This paper explores the factual possibility for these below-ground conditions and argues that approaches for relocation and rebuilding in Mexico City’s periphery are profoundly informed by historical processes that socially produce risk in marginalized areas.

Distribution Coefficient and Metal Pollution Index in Water and Sediments: Proposal of a New Index for Ecological Risk Assessment of Metals

The Lake of Texcoco is a closed basin with soils that confer salinity, conductivity, and alkalinity to it. It has undergone a reduction in size, incorporation of wastewater, and short-term desiccation, and includes temporary wetlands interconnected during the rainy season, some of which receive treated wastewater. Sediments contain metals, thus affecting water quality. Five artificial lakes were studied, and 12 metals (As, Ba, Cd, Cu, Cr, Fe, Mg, Mn, Hg, Ni, Pb, and Zn) were monitored bimonthly in water and sediments from June 2015 to March 2018. The Metal Pollution Index (MPI) and the Distribution Coefficient (Kd) were computed. Fe and Cd were the most and least stable metals in sediments, respectively (mean Log(Kd) = 4.24 and 2.079). Based on Log(Kd), metals were ranked as Fe &gt; Mn &gt; Zn &gt; Cu &gt; Mg &gt; Cr &gt; Ni &gt; Ba &gt; Pb &gt; Hg &gt; As &gt; Cd. Log(Kd) values &lt; 3 and &gt; 5 indicate that metals occur mainly in water and sediments, respectively. The Mean Distribution Coefficient Log(Kd MPI) is a novel index proposed to assess ecological risk from metals in a water body. This index allows determining the phase (liquid or solid) where metals predominate, negatively affecting either free-swimming or benthic organisms. Log(Kd MPI) values indicated that metals occur primarily in the liquid phase in all lakes studied.

Bacterial and archaeal spatial distribution and its environmental drivers in an extremely haloalkaline soil at the landscape scale.

BackgroundA great number of studies have shown that the distribution of microorganisms in the soil is not random, but that their abundance changes along environmental gradients (spatial patterns). The present study examined the spatial variability of the physicochemical characteristics of an extreme alkaline saline soil and how they controlled the archaeal and bacterial communities so as to determine the main spatial community drivers.MethodsThe archaeal and bacterial community structure, and soil characteristics were determined at 13 points along a 211 m transect in the former lake Texcoco. Geostatistical techniques were used to describe spatial patterns of the microbial community and soil characteristics and determine soil properties that defined the prokaryotic community structure.ResultsA high variability in electrolytic conductivity (EC) and water content (WC) was found. Euryarchaeota dominated Archaea, except when the EC was low. Proteobacteria, Bacteroidetes and Actinobacteria were the dominant bacterial phyla independent of large variations in certain soil characteristics. Multivariate analysis showed that soil WC affected the archaeal community structure and a geostatistical analysis found that variation in the relative abundance of Euryarchaeota was controlled by EC. The bacterial alpha diversity was less controlled by soil characteristics at the scale of this study than the archaeal alpha diversity.DiscussionResults indicated that WC and EC played a major role in driving the microbial communities distribution and scale and sampling strategies were important to define spatial patterns.

Genetic Variation among Island and Continental Populations of Burrowing Owl (Athene cunicularia) Subspecies in North America

Burrowing Owls (Athene cunicularia) have a large geographic range spanning both North and South America and resident populations occur on many islands in the eastern Pacific Ocean and the Caribbean Sea. Many owl populations are isolated and disjunct from other populations, but studies on genetic variation within and among populations are limited. We characterized DNA microsatellite variation in populations varying in size and geographic isolation in the Florida (A. c. floridana), the Western (A. c. hypugaea), and the Clarion (A. c. rostrata) subspecies of the Burrowing Owl. We also characterized genetic variation in a geographically isolated population of the western subspecies in central Mexico (near Texcoco Lake). Clarion Burrowing Owls had no intrapopulation variation (i.e., fixation) at 5 out of 11 microsatellite loci, a likely outcome of genetic drift in an isolated and small population. The Florida subspecies had only polymorphic loci but had reduced levels of genetic variation compared with the more-widespread western subspecies that occurs throughout western North America. Despite the extensive geographic distribution of the Western Burrowing Owl, we found genetic differentiation between the panmictic population north of the Trans-Mexican Volcanic Belt and the resident Texcoco Lake population in central Mexico.

Characterization of soil permeability in the former Lake Texcoco, Mexico

Abstract The geotechnical subsoil conditions of the former Lake Texcoco represent a complex sequence of highly compressible lacustrine clays interbedded with layers and seams of harder and more permeable materials. Although the mechanical properties of these deposits have been extensively studied in the past, the information about their hydraulic properties is scarce. Currently, a comprehensive characterization of the hydraulic conductivity of this site has become necessary because of the construction of the New Mexico International Airport (NAIM). The present study describes a systematic evaluation of the hydraulic conductivity in the former Lake Texcoco through three different in-situ methods (well permeameter, LEFRANC and piezocone dissipation test). The measurements, taken from 155 locations, show a high spatial variability, with ranges spanning more than two orders of magnitude. The results also reveal that the estimated permeabilities vary significantly among methods. These discrepancies reflect the scale dependency of the hydraulic conductivity in the area caused by soil heterogeneities. A comparison of the presented results with previous studies demonstrates that piezocone tests provide representative results for the clayey formations, while LEFRANC tests better estimate the hydraulic conductivity of the permeable strata. Besides, CPTu tests yield more consistent values of hydraulic conductivity, with smaller dispersion than well permeameter and LEFRANC tests.

Performance of a pavement foundation system based on the partial compensation of masses method

The system of the partial compensation of masses in the lacustrine zone of the Mexico Basin has been conceptualized, developed, used and improved over the past five decades as a foundation alternative for different types of roadways. This kind of foundation has been used in highways and runways built on lacustrine soils to reduce the settlement that can affect the service and operation conditions of those structures. In the construction of the new Mexico City International Airport in the Texcoco Lake area, various alternatives for runway foundations were evaluated through different test sections that were constructed to identify which of them would yield an adequate transfer of stress and prevent excessive total and differential deformations of the soil deposits. In this work, the behavior of the test section of the system of the partial compensation of masses, built in the Texcoco Lake area, is studied. An exploration campaign was performed; it consisted of different field and laboratory tests to determine the stratigraphic profile and the index and mechanical properties of the soil strata. Numerical models were applied using the finite element software PLAXIS 2D to analyze the behavior of the test section and to determine the maintenance frequency required to preserve the functionality of future runways. To validate the capability of the numerical models to properly simulate the stress-strain behavior of the test section, a comparative analysis was performed between the data obtained from the instrumentation installed on the test section and the results obtained from the finite element software. Once the numerical models were calibrated, the medium- and long-term behaviors of the test section were predicted, and the evolution over time of its surface geometry and transverse slopes were obtained.

A City on a Lake: Urban Political Ecology and the Growth of Mexico City by Matthew Vitz

Reviewed by: A City on a Lake: Urban Political Ecology and the Growth of Mexico City by Matthew Vitz Eric Spears A City on a Lake: Urban Political Ecology and the Growth of Mexico City. Matthew Vitz. Duke University Press, Durham, N.C., 2018. 338 pp.; maps, photos, notes, bibliog., and index. $27.95 (paperback) (ISBN-13: 978-0822370406). The literature in political ecology often focuses on contemporary problems and, at times, the forecasting of global capitalism’s impact on local environments and people. These approaches have been commonly used in the study of Latin American political ecology, where poverty, social marginalization, and ecological destruction are more pronounced on the landscape. Perhaps most noteworthy of these contemporary Latin American research efforts is the work done by Erik Swyndgedouw (1995) on the urban political ecology of water in Guayaquil, Ecuador. Other political ecology works tend to focus on the current state of the of the anthropocene era (Ernston and Swyngedouw, 2019). Matthew Vitz (2018), however, takes a decidedly different approach to understanding the political ecology and development of Latin America’s largest city, Mexico City. He looks at the city’s political ecology through an historical materialist perspective. Vitz’s book is part of a broader series by Duke University Press called Radical Perspectives: A Radical History of Review Book Series. Vitz’s recent publication of A City on a Lake: Urban Political Ecology and the Growth of Mexico City examines urban and environmental planning through the historical lens of politics, social struggle, and urban planning. Vitz bookends his Mexican study at the beginning of the twentieth century through the 1940s. He focuses on the Porfirian metropolitan environment through the rise of the Partido Nacional Revolucionario (PRI), which established itself as the dominate political party in Mexico. He maintains a political ecology tone throughout the book by writing “the politics of water and hygiene were the focal points of this (modernization) political transformation” (Vintz, p. 81). The decades within Vintz’s study provide an important glimpse into the federal district’s early efforts at modernization and urbanization, both of which established the precedent for the city’s exponential uneven development and environmental problems. The author argues that Mexico City’s modernization and urbanization are results of an “environmental technocracy”. The technocracy was represented by corrupted politics that favored large and expensive engineered solutions to urban planning at the detriment of marginalized communities. Vintz’s 1922 case study on the suppression of tenant rights movement exposes the power relations within a modernizing Mexico City (Vintz, p. 165). Vintz further explains Mexico City’s technocratic approach to urban planning with his case analysis of the Lake Texcoco reclamation project of the 1930s, which [End Page 324] spawned new single housing projects for the upper middle-class and wealthier elite. He writes about this production space in the following way: “Engineers operate amid ecological change and divergent social interests, and they respond to both social and environmental forces in accord with the interests they represent, in this case, urban-sanitary and class-infected political interests” (Vintz, p. 147). This historical analysis is reminiscent of David Harvey’s (1989) Grid of Spatial Practices, which is also based on Henri Lefebrve’s (1974) theory on the production of space, and within an historical materialist perspective of urban development and class struggle. Vintz’s research is not built on Harvey’s conceptual framework, per se, but does share its spirit of critical theory. Vintz presents a set of dialectical relations and modernism directed by another set of “elite environmental imaginaries, and vibrant natures interested to mold urban engineering schemes” (Vintz, p. 147). The author connects these environmental imaginaries to the impact of Mexico’s ejido system, a community-based and collective form of farming. Urban expansion and large-scale reclamation paved the way for the formation of Mexico City’s first modern shanty towns, as exemplified as colonia proleterias in flood-prone zones. Vintz makes an important contribution to political ecology’s literature and discourse. His research reminds us that environmental history is fundamental to our understanding of temporal productions of space—past and present. A City on a Lake is also an insightful glimpse into Mexico...

The new International Airport of Mexico City in the former lake of Texcoco, State of Mexico: problematic socioterritorial and environmental

The New International Airport of Mexico City is being built on lands outside Lake Texcoco. There is a socio-territorial and environmental planning problem in its construction. This project is not programmed or considered in the urban planning design of local, state or federal order, which allows us to know the lack of coordination between the different urban macro projects. At this moment, there is a change of land use not authorized by the local government, an area of ecological mitigation and rescue, which is now converted into an urban area where will be located the most important urban mega-project in Mexico in the last four decades. This work contains the explanation of the socio-territorial and environmental contradictions that are part of the dimensions of study. They are nourished with interviews and documentary information with an analytical perspective in order to know the various problems related to the New International Airport of Mexico City, which is built in a polygon of what used to be the Texcoco Lake, located in Texcoco City, State of Mexico.

English

Soil of the former lake Texcoco is nitrogen (N) depleted, so any attempt to vegetate the area will require the application of an N fertilizer. Urea is commonly used as fertilizer, but its application to soil might affect emissions of greenhouse gases (GHG), such as carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), and the high pH and electrolytic conductivity (EC) in the Texcoco soil might inhibit the hydrolysis of urea. Four soils of the former lake bed with EC 3.3, 88.3, 96.9, and 121 dS m-1, were amended with urea while dynamics of mineral N and emissions of GHG were monitored. Urea increased emission of CO2 in all soils and emission of N2O in soil with EC&le;88.3 dS m-1, but emission of CH4 was not affected. Hydrolysis of urea occurred in all soils although it was significantly lower in soil with EC&ge;88.3 dS m-1. Oxidation of NH4+ occurred in soil with EC&le;96.9 dS m-1, but oxidation of NO2- only in soil with EC 3.3 dS m-1. It was found that oxidation of NH4+ and NO2-, and hydrolysis of urea was inhibited by the high EC in soil of the former lake bed, while emissions of CO2 and N2O, but not CH4 were affected by application of urea. Key words: Carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), former lake bed, mineral N in soil. &nbsp