Preconsolidation pressure, soil water retention characteristics, and texture of Latosols in the Brazilian Cerrado

Soil Research ◽  
2013 ◽  
Vol 51 (3) ◽  
pp. 193 ◽  
Author(s):  
Eduardo da Costa Severiano ◽  
Geraldo César de Oliveira ◽  
Moacir de Souza Dias Junior ◽  
Nilton Curi ◽  
Kátia Aparecida de Pinho Costa ◽  
...  
Keyword(s):  
Water Retention ◽  
Structural Changes ◽  
Agricultural Land ◽  
Crop Yields ◽  
Particle Density ◽  
Clay Content ◽  
Total Porosity ◽  
Oxide Content ◽  
Brazilian Cerrado ◽  
Preconsolidation Pressure

In the Brazilian Cerrado Biome, Latosols (Oxisols) predominate on gently sloping areas and are highly suitable for the development of mechanised agriculture. However, inappropriate management may lead to reduced crop yields and environmental degradation. We examined the relationships between compression behaviour and texture of Latosols to support decisions on the sustainable use and management of agricultural land. We collected soil samples in 10 Latosols with variable textures under native vegetation and determined the oxide content, bulk and particle density, total porosity, water retention curves, and preconsolidation pressure at different water potentials to develop preconsolidation pressure models. Our results showed that soil texture influenced soil physical properties, that is, an increase in the clay content enhanced the total porosity and water retention and decreased bulk density. Consequently, the susceptibility of these soils to compaction increased with an increase in the clay content. Considering the characteristics of the machinery used in intensive Brazilian agriculture, the compaction risk of these soils was considered high, despite the differences in resistance of the soils. In clayey and very clayey soils, some additional compaction is almost inevitable, even when the water content is low. Thus, caution is required in the evaluation of structural changes after mechanised field operations.

scholarly journals Structural changes in latosols of the cerrado region: II - soil compressive behavior and modeling of additional compaction

2011 ◽  
Vol 35 (3) ◽  
pp. 783-791 ◽  
Author(s):  
Eduardo da Costa Severiano ◽  
Geraldo César de Oliveira ◽  
Moacir de Souza Dias Júnior ◽  
Katia Aparecida de Pinho Costa ◽  
Vinícius de Melo Benites ◽  
...  
Keyword(s):  
Soil Compaction ◽  
Critical Pressure ◽  
Water Retention ◽  
Structural Changes ◽  
Compressive Behavior ◽  
Undisturbed Samples ◽  
Preconsolidation Pressure ◽  
Density Values ◽  
Soil Compression ◽  
Region Ii

Currently in Brazil, as in other parts of the world, the concern is great with the increase of degraded agricultural soil, which is mostly related to the occurrence of soil compaction. Although soil texture is recognized as a very important component in the soil compressive behaviors, there are few studies that quantify its influence on the structural changes of Latosols in the Brazilian Cerrado region. This study aimed to evaluate structural changes and the compressive behavior of Latosols in Rio Verde, Goiás, through the modeling of additional soil compaction. The study was carried out using five Latosols with very different textures, under different soil compaction levels. Water retention and soil compression curves, and bearing capacity models were determined from undisturbed samples collected on the B horizons. Results indicated that clayey and very clayey Latosols were more susceptible to compression than medium-textured soils. Soil compression curves at density values associate with edaphic functions were used to determine the beneficial pressure (σ b) , i.e., pressure with optimal water retention, and critical pressure (σcrMAC), i.e., pressure with macroporosity below critical levels. These pressure values were higher than the preconsolidation pressure (σp), and therefore characterized as additional compaction. Based on the compressive behavior of these Latosols, it can be concluded that the combined preconsolidation pressure, beneficial pressure and critical pressure allow a better understanding of compression processes of Latosols.

scholarly journals Characterization and Classification of soils on different Geomorphic Units of North-Eastern Haryana, India

Agropedology ◽  
2019 ◽  
Vol 27 (2) ◽  
Author(s):  
◽  
Mohammad Amin Bhat ◽  
K.S. Grewal ◽  
◽  
Keyword(s):  
Water Retention ◽  
Particle Density ◽  
Total Porosity ◽  
Exchange Capacity ◽  
Flood Plains ◽  
North Eastern ◽  
Retention Characteristics ◽  
Geomorphic Units ◽  
Physical And Chemical

Twelve pedons occurring on different landforms of North-Eastern Haryana were characterized for morphological, physical and chemical characteristics and classified. The soil colour of pedons varied from yellowish brown to reddish/ dark brown in the hues of 10YR, 5YR and 2.5YR. The soils of Shiwalik hills, upper piedmont plains and flood plains, lower piedmont plains and old alluvial plains were medium to moderately heavy in texture, relatively lighter and light to moderately heavy in texture, respectively. The soils have weak to medium subangular blocky structure. The sub surface horizons in old alluvial plains showed the translocation and accumulation of clay. The soils of the area were moderately alkaline to strongly alkaline (pH 7.5-9.4). The organic carbon was less than 1 per cent except surface horizons of forest areas. The water retention characteristics of soils were strongly associated to texture with the finer soil showing higher retention and vice-versa. The particle density, bulk density and total porosity varied from 2.20 to 2.84, 1.16 to 1.45 Mg m−3 and 40.43 to 56.78 per cent, respectively and did not show regular pattern down the profile. The cation exchange capacity varied from 5.21 to 17.00 cmol (p+) kg−1.

scholarly journals Physical Atributes of a Oxisol from the Brazilian Cerrado under Different Management Systems

2017 ◽  
Vol 10 (1) ◽  
pp. 361
Author(s):  
Márcio Godofrêdo Rocha Lobato ◽  
Fabrício Menezes Telo Sampaio ◽  
Júlio César Azevedo Nóbrega ◽  
Mozart Martins Ferreira ◽  
Sammy Sidney Rocha Matias ◽  
...  
Keyword(s):  
Physical Properties ◽  
Particle Density ◽  
Aggregate Stability ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Management Systems ◽  
Porous Space ◽  
Brazilian Cerrado ◽  
Tillage Systems ◽  
No Till

The tillage systems induce changes in soil structure; modify the porous space, and influence soil water and air dynamics. In this sense, it is important to evaluate these impacts on soil physical quality according to different tillage system with distinct years of implementation. The physical properties of a Oxisol at the Brazilian Cerrado with distinct tillage conditions (conventional, no-till, and a native Cerrado) with different years were compared. The study was conducted at Novo Horizonte farm, at the Cerrado region of southwest Piauí. Soil samples were collected at 0.0-0.10, 0.10-0.20 and 0.20-0.30 m depth in different management systems: no-till with three and five years of implantation (NT3 and NT5, respectively); conventional till with five and nine years (CC5 and CC9, respectively); and a native cerrado area. Were analyzed the aggregate stability in water, soil bulk density, particle density, macro and microporosity, total porosity and total organic carbon. The years of implementation of the tillage systems caused changes in the soil physical properties, which were more evident in the surface layer. Although improved soil physical attributes were observed in no-till after five years of implantation, a longer evaluation time is required for the studied conditions.

Justification of the need to increase the fertility of reclaimed alluvial soils of JSC «Moskovskoe»

2020 ◽  
pp. 44-48
Author(s):  
Andrey ilinsky ◽  
Alexander Nefedov ◽  
Konstantin Evsenkin
Keyword(s):  
Organic Matter ◽  
Agricultural Land ◽  
Crop Yields ◽  
Anthropogenic Impacts ◽  
Fertility Restoration ◽  
Research Work ◽  
Alluvial Soils ◽  
Ecological Stability ◽  
Reclaimed Land ◽  
Adverse Weather

Global climatic changes, technogenic pollution by pollutants, violations of technologies of exploitation of reclaimed land lead to a decrease in fertility and soil degradation of agricultural land. Adverse weather conditions, resulting in a lack of adequate flood water, and economic difficulties in agriculture make it difficult to fill the deficit of organic matter and macronutrients in reclaimed alluvial soils. The monitoring of agrochemical properties of alluvial meadow medium-loamy soil of the stationary site (reclaimed lands of JSC «Moskovskoye» of Ryazan region), located in the floodplain of the Oka river, conducted by the Meshchersky branch of Vniigim, showed the presence and intensification of degradation changes in the soil. Thus, comparing the agrochemical indicators in the layer 0–20 cm, carried out in 1995, with the indicators of 2019, it should be noted a decrease in soil fertility. The decrease in soil quality was expressed in a decrease in the amount of mobile phosphorus by 37.6 %, mobile potassium by 53.3 %. Also, during this time there was a decrease in organic matter by 9.1 %, and an increase in soil acidity was 0.6 pH. As a result of such changes, soils lose ecological stability and become more vulnerable to adverse weather and negative anthropogenic impacts. In such a situation, advanced agricultural techniques should be actively used to obtain guaranteed, environmentally safe crop yields and restore the fertility of degraded reclaimed soils. In this regard, there is a need to develop innovative methods of fertility restoration of degraded alluvial soils in reclaimed lands using multi-component organic-mineral ameliorants. Meshchersky branch performs research work in addressing this issue.

Ukrainian Chernozem Fertility Reproduction under Soil Conservation Agriculture

2020 ◽  
pp. 67-79
Author(s):  
Yu. Kravchenko
Keyword(s):  
Soil Conservation ◽  
Agricultural Land ◽  
Crop Yields ◽  
Conservation Agriculture ◽  
Instructional Materials ◽  
Cultivated Plants ◽  
Forest Steppe ◽  
Typical Chernozem ◽  
Degradation Processes ◽  
Biological Potential

In Ukraine 57.5 % of agricultural land is subjected to erosion with 10–24 million tons of humus, 0.3–0.96 million tons of nitrogen, 0.7–0.9 million tons of phosphorus and 6–12 million tons of potassium lost annually. Degradation processes are also common on chernozems, which cover about 60 % of the Ukrainian territory. The aim of the research is to defi ne the most eff ective soil conservation practices and legislative decisions aimed to conservation/recovering the Ukrainian chernozem fertility. The experimental data of the agrochemical certifi cation of Ukrainian lands, data from scientifi c papers, stock and instructional materials as well as our own fi eld and laboratory studies were used. It has been established that the long-term use of deep subsurface tillage on typical chernozem increases, compared with plowing, the content of 10–0.25 mm of air-dry and water-resistant aggregates, the bulk density, soil water storages, water infi ltration rates, the content of mobile phosphorus and exchangeable potassium, pHH2O, CaCO3 stocks, the contents of humic and fulvic acids, molecular weights of humic acids – by 5.5 and 3.06 %; 0.05 g/cm3; 25.5 mm; 22.6 mm/h; 0.1 and 3 mg/100 g of soil; 0.03 pHH2O; 18 t/ha, 0.02 and 0.04 %, 91195 kDa, respectively. Fertilizers may contribute to the crop yields increase from by 60% in the Polissya, by 40 % – in the Forest Steppe, by 15 % – in the Wet Steppe, by 10 % – in the Dry Steppe and by 40 % – in the Irrigated Steppe areas. In soil-conservation rotations, the crop placement and alternation are advisable to combine with strips or hills sowing, taking into account the local relief features; soil alkalinization, applying anti-erosion structures. Ukrainian agriculture will receive additional 10–12 million tons of forage units or 20–22 % from all fodder in a fi eld agriculture under increasing 8–10 % of arable lands for intercrops. It is advisable to mulch the eroded chernozems of Ukraine depending on their texture composition: 1.3 t/ha of mulch for sandy and loamy soils, 1.9 t/ha – for sandy and 1.1 t/ha – for loamy soils. The implementation of soil conservation agriculture can minimize some soil degradation processes and improve eff ective soil properties required to realize the biological potential of cultivated plants. Key words: chernozem, degradation, fertility, soil conservation technologies, agriculture policy.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

scholarly journals European survey shows poor association between soil organic matter and crop yields

2020 ◽  
Vol 118 (3) ◽  
pp. 325-334
Author(s):  
Wytse J. Vonk ◽  
Martin K. van Ittersum ◽  
Pytrik Reidsma ◽  
Laura Zavattaro ◽  
Luca Bechini ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Sugar Beet ◽  
Significant Positive Correlation ◽  
Agricultural Land ◽  
Crop Yields ◽  
Carbon Sink ◽  
Significant Negative Correlation ◽  
Positive Correlation ◽  
Farm Survey

AbstractA number of policies proposed to increase soil organic matter (SOM) content in agricultural land as a carbon sink and to enhance soil fertility. Relations between SOM content and crop yields however remain uncertain. In a recent farm survey across six European countries, farmers reported both their crop yields and their SOM content. For four widely grown crops (wheat, grain maize, sugar beet and potato), correlations were explored between reported crop yields and SOM content (N = 1264). To explain observed variability, climate, soil texture, slope, tillage intensity, fertilisation and irrigation were added as co-variables in a linear regression model. No consistent correlations were observed for any of the crop types. For wheat, a significant positive correlation (p < 0.05) was observed between SOM and crop yields in the Continental climate, with yields being on average 263 ± 4 (95% CI) kg ha−1 higher on soils with one percentage point more SOM. In the Atlantic climate, a significant negative correlation was observed for wheat, with yields being on average 75 ± 2 (95%CI) kg ha−1 lower on soils with one percentage point more SOM (p < 0.05). For sugar beet, a significant positive correlation (p < 0.05) between SOM and crop yields was suggested for all climate zones, but this depended on a number of relatively low yield observations. For potatoes and maize, no significant correlations were observed between SOM content and crop yields. These findings indicate the need for a diversified strategy across soil types, crops and climates when seeking farmers’ support to increase SOM.

Thermo-Optical Properties of Perfluorinated Sulfonic Acid Membranes: An Investigation of Hydration Based on Absorption Spectra

2017 ◽  
Vol 71 (11) ◽  
pp. 2504-2511 ◽  
Author(s):  
Daniele T. Dias ◽  
Guy Lopes ◽  
Tales Ferreira ◽  
Ivanir L. Oliveira ◽  
Caroline D. Rosa
Keyword(s):  
Sulfonic Acid ◽  
Room Temperature ◽  
Water Retention ◽  
Structural Changes ◽  
Optical Characterization ◽  
Scanning Calorimetry ◽  
Experimental Procedure ◽  
Nafion Membranes ◽  
Perfluorinated Sulfonic Acid

The Nafion membranes are widely used in electrochemical applications such as fuel cells, chlor-alkali cells, and actuators–sensors. In this work, the thermal-optical characterization of Nafion in acid form was performed by photoacoustic spectroscopy, thermogravimetry, and differential scanning calorimetry. In the experimental procedure three distinct hydration levels were considered: (1) pristine membrane (λ ≅ H2O/–SO3H ≅ 5.6); (2) swelling process (λ ≅ 17.4); and (3) drying at controlled room temperature after swelling process (λ ≅ 6.5). The discovered behaviors showed significant irreversible structural changes induced by water retention in the membrane. These structural changes depend on the water population present in the clusters and also affect the directional thermal diffusivity of the membrane irreversibly.

Influence of Compaction Energy and Bentonite Clay Content in the Soil Hydraulic Conductivity

2016 ◽  
Vol 851 ◽  
pp. 858-863
Author(s):  
Osvaldo de Freitas Neto ◽  
Olavo Francisco dos Santos Jr. ◽  
Fagner Alexandre Nunes de França ◽  
Ricardo Nascimento Flores Severo
Keyword(s):  
Soil Sample ◽  
Laboratory Tests ◽  
Particle Density ◽  
Bentonite Clay ◽  
Clay Content ◽  
Capital City ◽  
Silty Sand ◽  
Laboratory Test Results ◽  
Compaction Energy ◽  
Field Works

This paper intends to evaluate changes in permeability of a soil sample from Formação Barreiras, in Natal, the capital city of Rio Grande do Norte State, related to the degree of compaction and the adding of clay to the soil sample. In field works, samples were collected and permeability and density tests were performed. In laboratory, grain size distribution, Attemberg limits and particle density tests were conducted. Afterwards, compaction and permeability tests fulfilled the set of laboratory tests, with changes in compactive energy and sample clay content. The results from field and laboratory tests were compared and the relationship between compaction energy and sample clay content were portrayed. The soil was classified as silty sand. Field and laboratory test results were quite similar. As expected, the tests indicated that permeability is inversely proportional to both compaction energy and sample clay content in the soil tested.

SOIL CONDITIONERS—THEIR EFFECT ON COARSE-TEXTURED SOILS, CROP YIELDS AND COMPOSITION

1957 ◽  
Vol 37 (2) ◽  
pp. 102-112
Author(s):  
R. M. Holmes ◽  
S. J. Toth
Keyword(s):  
Structural Changes ◽  
Crop Yields ◽  
Cultural Practices ◽  
Sandy Soils ◽  
Growing Season ◽  
Soil Aggregate ◽  
Crop Response ◽  
The Third ◽  
Soil Conditioners ◽  
The Stability

Crop response to soil structural changes caused by soil conditioner amendments was studied in several different sandy soils of New Jersey. The response varied with the crop and treatment. Those chemicals that were slightly hydrophobic were most effective and generally crop response was greatest on these treatments. Cations such as Na may be added in large amounts as part of some conditioners, and this may result in reduced uptake of other nutrients such as Mg. and K. Except for this effect, conditioners did not reduce nutrient uptake by plants. When elements such as Na and N are added in large amounts as part of some conditioners, there may be an increased uptake of these nutrients.Catalin and VAMA conditioners produced a dry surface mulch which appeared to reduce evaporation. Moisture reserves were, therefore, preserved through a drought and this resulted in increased growth of crops over those grown on other treatments. Cultural practices destroyed the stability of the conditioned aggregates, since in most cases the effect had largely disappeared by the third growing season. Chemicals which were effective in soil aggregate stabilization were also effective as anti-crustants when crusting was a problem.

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