scholarly journals Artificial chinampas soils of Mexico City: their properties and salinization hazards .

2014 ◽  
Vol 1 ◽  
Author(s):  
Pavel Krasilnikov ◽  
Norma Eugenia García Calderón ◽  
Rosalía Ramos Bello ◽  
Héctor Manuel Ortega Escobar
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Vertical Distribution ◽  
Mexico City ◽  
Organic Matter Content ◽  
Lacustrine Sediments ◽  
Soil Salinization ◽  
Matter Content ◽  
Soluble Salts ◽  
Wide Range

The chinampas agriculture is a traditional land use practice in the Valley of Mexico since Pre-Hispanic time. The chinampas soils were constructed by excavation of lake sediments that resulted in the creation of a system of islands separated by channels. The agricultural productivity of these artificial soils was high; also the land use practices included forestry, fish breeding and hunting. Nowadays, the chinampas soils are affected by excessive salinity. We studied 10 representative soil profiles in the chinampas zone of Mexico City in order to characterize their properties and origin, to provide their classification, and to evaluate soil salinization, vertical distribution of the salts and their chemical composition. The soils are characterized by a layered structure, uniform dark grey colour, irregular vertical distribution of organic carbon and clay, and high percentage of carbon. Some soils show an increase in organic matter with depth, and other profiles have maximum organic matter content in the surficial layers and in the subsoil. The dynamics of sedimentation resulted in the decrease in organic matter in the upper layers of lacustrine sediments, because of recent increase in erosion rate and consequent increase in the proportion of mineral particles in the sediments. Most probably high organic matter content in surficial layers of some soils is due to excavation and accumulation of organic-rich subsoil material in the course of digging the channels. The concentration of soluble salts in superficial horizons, expressed as electric conductivity, varies in a wide range from 5 to almost 50 dS·m<sup>-1</sup>. The salts concentrate mainly in the superficial layers of soils. The abundance of the cations of soluble salts is Na<sup>+</sup>&gt;Mg<sup>2+</sup>&gt;Ca<sup>2+</sup>&gt;K<sup>+</sup> and that of the anions is SO<sub>4</sub><sup>2-</sup>&gt;Cl<sup>-</sup>&gt;HCO<sub>3</sub><sup>-</sup>&gt;CO<sub>3</sub><sup>2-</sup>. The alkaline reaction of soils is caused by exchangeable Na rather than by free sodium carbonates. The restoration of chinampas requires a complex approach, combining soil, water and ecosystems remediation.

The Effects of Long‐Term Land‐Use Change on Soil Properties in Perth, Ontario Canada

2016 ◽  
Author(s):  
Trina Stephens
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
North America ◽  
Land Use Change ◽  
Soil Properties ◽  
Carbon Storage ◽  
Organic Matter Content ◽  
Matter Content ◽  
Topographic Gradients

Land‐use change can have a major impact on soil properties, leading to long‐term changes in soilnutrient cycling rates and carbon storage. While a substantial amount of research has been conducted onland‐use change in tropical regions, empirical evidence of long‐term conversion of forested land toagricultural land in North America is lacking. Pervasive deforestation for the sake of agriculturethroughout much of North America is likely to have modified soil properties, with implications for theglobal climate. Here, we examined the response of physical, chemical and biological soil properties toconversion of forest to agricultural land (100 years ago) on Roebuck Farm near Perth, Ontario, Canada.Soil samples were collected at three sites from under forest and agricultural vegetative cover on bothhigh‐ and low‐lying topographic positions (12 locations in total; soil profile sampled to a depth of 40cm).Our results revealed that bulk density, pH, and nitrate concentrations were all higher in soils collectedfrom cultivate sites. In contrast, samples from forested sites exhibited greater water‐holding capacity,porosity, organic matter content, ammonia concentrations and cation exchange capacity. Many of these characteristics are linked to greater organic matter abundance and diversity in soils under forestvegetation as compared with agricultural soils. Microbial activity and Q10 values were also higher in theforest soils. While soil properties in the forest were fairly similar across topographic gradients, low‐lyingpositions under agricultural regions had higher bulk density and organic matter content than upslopepositions, suggesting significant movement of material along topographic gradients. Differences in soilproperties are attributed largely to increased compaction and loss of organic matter inputs in theagricultural system. Our results suggest that the conversion of forested land cover to agriculture landcover reduces soil quality and carbon storage, alters long‐term site productivity, and contributes toincreased atmospheric carbon dioxide concentrations.

Relationship between soil composition and retention capacity of terbumeton onto chalky soils

2009 ◽  
Vol 6 (3) ◽  
pp. 245 ◽  
Author(s):  
Achouak El Arfaoui ◽  
Stéphanie Sayen ◽  
Eric Marceau ◽  
Lorenzo Stievano ◽  
Emmanuel Guillon ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Environmental Fate ◽  
Organic Matter Content ◽  
Calcareous Soils ◽  
Matter Content ◽  
Soil Composition ◽  
Retention Capacity ◽  
Wide Range ◽  
Soil Components

Environmental context. The wide use of pesticides for pest and weed control contributes to their presence in underground and surface waters, which has led to a continuously growing interest in their environmental fate. Soils play a key role in the transfer of these compounds from the sprayer to the water as a result of their capacity to retain pesticides depending on the soil components. The knowledge of soil composition should enable one to predict pesticide behaviour in the environment. Abstract. Eight calcareous soils of Champagne vineyards (France) were studied to investigate the adsorption of the herbicide terbumeton (TER). A preliminary characterisation of the soil samples using X-ray diffraction (XRD), elemental and textural analyses, revealed a wide range of soil properties for the selected samples. The adsorption isotherms of TER were plotted for all samples. The determination of soil properties, which significantly correlated with the Kd distribution coefficient, allowed identification of organic matter and CaCO3 as the two main soil components that govern the retention of the herbicide. Organic matter was the predominant phase involved in the retention but its role was limited by the presence of calcite. Finally, the ratio of CaCO3 content to organic matter content was proposed as a useful parameter to predict the adsorption of terbumeton in chalky soils. The evolution of Kd as a function of this ratio was successfully described using an empirical model.

scholarly journals The color of refractory organic carbon

2018 ◽  
Vol 189 (2) ◽  
pp. 9 ◽  
Author(s):  
Maxime Debret ◽  
Yoann Copard ◽  
Antonin Van Exem ◽  
Geneviève Bessereau ◽  
Frank Haeseler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Carbon Content ◽  
Anthropogenic Activities ◽  
Organic Matter Content ◽  
Matter Content ◽  
Mineral Matter ◽  
Organic Carbon Content ◽  
Fast Method ◽  
Wide Range

Organic matter studies find an echo within different topics such as biogeochemical cycles, processes occurring in continental surfaces, anthropogenic activities, climate science, earth and planetary sciences, etc. Today’s challenges include finding and developing the most appropriate method(s) supporting the differentiation and characterisation of various types of recalcitrant organic matter in modern environments. In this study, we focus on combustion residues and coals as these two types of organic matter contain a significant amount of so-called recalcitrant organic carbon (black carbon and fossil organic carbon). Both these materials are ubiquitous, broadly stem from the same living organisms and have similar polyaromatic structures. In this respect, we tested a spectrophotometry method, classically used for sedimentology, as a very fast method for preliminary investigations. Analyses were performed with a wide range of standards and referenced samples. The results discriminate three different spectral signatures related to the degree of transformation of organic matter related to the degree of aromaticity (i.e. carbonisation). Using calibration curves, total organic carbon content can be estimated in experimental mixes with mineral matter and in a real context using subsurface sample (Gironville 101 borehole, Paris Basin, France). This method has particularly high sensitivity to very low organic matter content and is shown to be promising for a rapid evaluation of the organic carbon content.

scholarly journals Diversity and Distribution of Naked Amoebae in Water Bodies of Sumy Region (Ukraine)

2019 ◽  
Vol 53 (3) ◽  
pp. 177-186 ◽  
Author(s):  
M. K. Patsyuk ◽  
I. P. Onyshchuk
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Bodies ◽  
Ecological Groups ◽  
Riparian Species ◽  
Species Complexes ◽  
Wide Range ◽  
Naked Amoebae

Abstract Taxonomy of naked amoebae and specifics of their distribution in water bodies of Sumy Region are presented. Our research identified 12 species of naked amoebae of 11 morphotypes. We established their ecological groups relative to abiotic aquatic factors: euryoxidic, stenooxidic, stenobiotic and those that survive in a wide range of organic matter content. According to the species composition, swamp and riparian species complexes of naked amoebae were identified. It was found that species complexes of amoeba are influenced by such factors as temperature, concentration of dissolved oxygen and organic compounds.

Empirical Analysis on the Influence of Different Land Use on Soil Organic Matter

2014 ◽  
Vol 484-485 ◽  
pp. 127-131
Author(s):  
Han Zheng Kong ◽  
Ju Sheng Jiang ◽  
Zong Bo Peng ◽  
Yu Jie Zhou
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Secondary Forest ◽  
Soil Layer ◽  
Organic Matter Content ◽  
Matter Content ◽  
Rubber Plantation ◽  
Land Use Patterns ◽  
Tillage Method

In this paper, we take secondary forest, orchard, and woodland soils of rubber in different planting years as a research subject and analyze the influence of different land use on soil organic matter. The results show that land use has significant influence on soil organic matter components (p <0.01). We conducted a survey and sampling on 10 age classes of Hainan Dongfang Daguangba (3, 8, 13, 18,23,29,33,35,38,42 years old) rubber plantation plots soil layer (0 cm-20 cm, 20 cm-40 cm), and conducted in-house testing analysis of its organic matter content, and achieved preliminary exploration that soil organic matter content of different land use patterns in Dongfang City in Hainan: secondary forest> orchard> rubber plantation. These differences are mainly due to the litter under different tillage quantity, quality and variety of management measures. While orchards and rubber plantation have used different tillage method, as a plantation by human, it was greatly influenced by human.

scholarly journals Sustainable land use and soil quality: organic matter as an indicator

2003 ◽  
Vol 22 (4) ◽  
pp. 106-112 ◽  
Author(s):  
C. C. Du Preez
Keyword(s):  
South Africa ◽  
Land Use ◽  
Organic Matter ◽  
Soil Quality ◽  
Soil Degradation ◽  
Organic Matter Content ◽  
Matter Content ◽  
Sustainable Land Use ◽  
Important Indicator ◽  
Recent Approach

In this review the most recent approach to sustainable land use and the role that soil quality plays therein are described briefly. The requirements to which indicators must conform for the meaningful evaluation of the quality of soil and sustainability of land use are also elucidated. Thereafter the processes of physical, chemical and biological soil degradation are given. A concise discussion follows on the extent of physical and chemical soil degradation in South Africa, of which there is reliable information. Biological soil degradation is treated in more detail. Attention is given firstly to the role of soil organic matter in biogeochemical cycles. Thereafter the influence of different land use systems in the central parts of South Africa on the organic matter content and consequently the nitrogen, phosphorus and sulphur reserves of soils is discussed by using examples. The conclusion is that organic matter is an important indicator of soil quality and thus also of sustainable land use.

scholarly journals Warming increases carbon-nutrient fluxes from sediments in streams across land use

2012 ◽  
Vol 9 (8) ◽  
pp. 11293-11330
Author(s):  
S.-W. Duan ◽  
S. S. Kaushal
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Sulfate Reduction ◽  
Organic Matter Content ◽  
Soluble Reactive Phosphorus ◽  
Matter Content ◽  
Overlying Water ◽  
Watershed Land Use ◽  
Sediment Fluxes

Abstract. Rising water temperatures due to climate and land-use change can accelerate biogeochemical fluxes from sediments to streams. We investigated impacts of increased streamwater temperatures on sediment fluxes of dissolved organic carbon (DOC), nitrate, soluble reactive phosphorus (SRP) and sulfate. Experiments were conducted at 8 long-term monitoring sites across land use (forest, agricultural, suburban, and urban) at the Baltimore Ecosystem Study Long-Term Ecological Research (LTER) site in the Chesapeake Bay watershed. Over 20 yr of routine water temperature data showed substantial variation across seasons and years, and lab incubations were conducted at 4 temperatures (4 °C, 15 °C, 25 °C and 35 °C) for 48 h. Results indicated: (1) warming consistently increased sediment DOC fluxes to overlying water across land use but decreased DOC quality via increases in the humic-like to protein-like fractions (2) warming consistently increased SRP fluxes from sediments to overlying water across land use (3) warming increased sulfate fluxes from sediments to overlying water at rural/suburban sites but decreased sulfate fluxes at urban sites likely due to sulfate reduction (4) nitrate fluxes showed an increasing trend with temperature but with larger variability than SRP. Sediment fluxes of nitrate, SRP and sulfate were strongly related to watershed urbanization and organic matter content. Using relationships of sediment fluxes with temperature, we estimate a 5 °C warming would increase the annual sediment release by 1.0–3.9 times. In addition to hydrologic variability, understanding warming impacts on coupled biogeochemical cycles in streams (e.g., organic matter mineralization, P sorption, nitrification, denitrification, and sulfate reduction) is critical for forecasting changes in carbon and nutrient exports across watershed land use.

scholarly journals Maize Inoculation with Microbial Consortia: Contrasting Effects on Rhizosphere Activities, Nutrient Acquisition and Early Growth in Different Soils

2019 ◽  
Vol 7 (9) ◽  
pp. 329 ◽  
Author(s):  
Klára Bradáčová ◽  
Maximilian Sittinger ◽  
Katharina Tietz ◽  
Benjamin Neuhäuser ◽  
Ellen Kandeler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Activity ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nutrient Acquisition ◽  
Microbial Consortia ◽  
P Cycling ◽  
Major Mode ◽  
Wide Range ◽  
N And P Cycling

The benefit of plant growth-promoting microorganisms (PGPMs) as plant inoculants is influenced by a wide range of environmental factors. Therefore, microbial consortia products (MCPs) based on multiple PGPM strains with complementary functions, have been proposed as superior, particularly under challenging environmental conditions and for restoration of beneficial microbial communities in disturbed soil environments. To test this hypothesis, the performance of a commercial MCP inoculant based on 22 PGPM strains was investigated in greenhouse experiments with maize on three soils with contrasting pH, organic matter content and microbial activity, under different P and N fertilization regimes. Interestingly, the MCP inoculant stimulated root and shoot growth and improved the acquisition of macronutrients only on a freshly collected field soil with high organic matter content, exclusively in combination with stabilized ammonium fertilization. This was associated with transiently increased expression of AuxIAA5 in the root tissue, a gene responsive to exogenous auxin supply, suggesting root growth promotion by microbial auxin production as a major mode of action of the MCP inoculant. High microbial activity was indicated by intense expression of soil enzyme activities involved in C, N and P cycling in the rhizosphere (cellulase, leucine peptidase, alkaline and acid phosphatases) but without MCP effects. By contrast, the MCP inoculation did not affect maize biomass production or nutrient acquisition on soils with very little Corg and low microbial activity, although moderate stimulation of rhizosphere enzymes involved in N and P cycling was recorded. There was also no indication for MCP-induced solubilization of Ca-phosphates on a calcareous sub-soil fertilized with rock-phosphate. The results demonstrate that the combination of multiple PGPM strains with complementary properties as MCP inoculants does not necessarily translate into plant benefits in challenging environments. Thus, a better understanding of the conditions determining successful MCP application is mandatory.

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