scholarly journals Soil susceptibility to compaction under use conditions in southern Brazil

2017 ◽  
Vol 41 (1) ◽  
pp. 60-71 ◽  
Author(s):  
Michael Mazurana ◽  
Renato Levien ◽  
Alberto Vasconcellos Inda Junior ◽  
Osmar Conte ◽  
Luiz Antônio Bressani ◽  
...  

ABSTRACT The degree of soil compaction is intensified by its inadequate management, compaction being variable depending on soil type since even under identical management conditions, different types have different abilities to withstand load. The objective of this study was to evaluate the susceptibility to compaction of different classes of soils under no-tillage (NT) croping system compared to the original condition. Thus, i) soils with the same source material have distinct resistance to compression with increased NT adoption time; ii) the most sensitive indicators of this change are the ratios mass:volume and volume:volume and; iii) there is a relationship between resistance and compaction susceptibility with the amount and type of oxide. Soil samples were collected in areas under NT and under natural condition in order to assess the impact imposed by the NT on the attributes density and porosity, precompression stress and compressibility index and relate them to the oxide type of, and content in, the soils under study. The results show that the density and macroporosity were those most affected by the NT agricultural use, regardless of soil type, that is, its dynamic is related more to soil use and less to mineralogical characteristics. The soil resistance and compaction susceptibility were higher in soil developed in basalt, followed by those developed in sandstone and granite. Both the organic matter content and type and concentration of iron oxides were related to the soil resistance and susceptibility to compaction.

Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 564-567 ◽  
Author(s):  
Glen P. Murphy ◽  
David R. Shaw

Research was conducted in 1994 and 1995 to evaluate the field mobility of flumetsulam in three soils of varied texture and organic matter content but constant pH (pH = 6.0 ± 0.1). Flumetsulam was monitored to a depth of 122 cm at 28, 56, and 84 days after treatment (DAT). Flumetsulam concentrations were determined by cotton bioassay, with separate standard curves for various soil–depth combinations. Following a preemergence application of flumetsulam at 224 g ai ha−1, the herbicide was primarily limited to the upper 8 cm of soil, regardless of soil type, year, or DAT. Exceptions to this typically occurred following substantial rainfall amounts early in the season. Beyond 28 DAT, no significant concentrations of flumetsulam were detected below 15 cm. Results from this research suggest that leaching is not a significant route of flumetsulam dissipation in the field.


Author(s):  
Progress Oghenerume ◽  
Samuel Eduok ◽  
Basil Ita ◽  
Ofonime John ◽  
Inemesit Bassey

We evaluated the effect of 4000 mg zinc oxide (ZnO, 99%, 30 nm) nanoparticle on the physicochemical and microbiological properties of organic manure amended ultisol and loam soil cultivated with Arachis hypogaea using standard methods. The results indicate varying effects on the physicochemical properties in relation to the soil type. The pH of the control ultisol at 7.85 ± 0.17 and 8.3 ± 0.12 in the amended ultisol whereas, the control loam was 7.15 ± 0.17 and 7.41 ± 0.11 in the amended soil indicating 1.06- and 1.04-times higher difference than the controls respectively.  Phosphorus concentration at 57.82 ± 0.54%, 50.81 ± 0.22% and 55.97 ± 0.04%, 59.97 ± 0.02% was 1.14 times lower in the ZnO amended ultisol and 1.07 times higher in amended loam soil compared to the respective controls. The organic matter content in the control and amended ultisol was 2.28 ± 0.32% and 0.91 ± 0.02%, 3.68 ± 0.36% and 0.36 ± 0.02% in the control and amended loam soil. The concentration of nitrate in the control ultisol was 0.05 ± 0.01% and 0.03 ± 0.01% in the amended soil. The nitrate in the control loam soil was 0.08 ± 0.01% relative to 0.02 ± 0.01% in the treated soil and these differences were significant at p = 0.05. The concentration of nutritive salts was reduced and in contrast iron, copper, exchangeable acids, exchange capacity, clay and silt increased in the amended soils. Further to this, heterotrophic ammonia and nitrate-oxidizing bacterial population were inhibited in the amended soils and denitrifying organisms were stimulated. The organisms were members of the genera Pseudomonas, Xanthobacter, Enterobacter, Bacillus, Lactobacillus, Citrobacter, Nitrosomonas, Agromyces and Rhizobium. ZnO nanoparticles altered the soil physicochemical properties which exacerbated the negative effect on microbial abundance and varied with the soil type.


Author(s):  
Justyna Kujawska ◽  
Katarzyna Wójcik-Oliveira

Sewage sludge and its management constitute one of the most important environmental problems. The introduced the Sewage Sludge Directive 86/278/EEC advocate utilization of sewage sludge in agriculture. However, this method is limited mainly by the availability of heavy metals and pathogens. An ecotoxicological assessment of sewage sludge doses applied to soil, recommended in the Polish Regulation of the Minister of Environment of 6th February 2015 on municipial sewage sludge, was carried out. The sewage sludge was added to soil in the amounts of 3, 6, 9, and 15 Mg/ha. The produced mixtures were subjected to physicochemical and ecotoxicological tests, involving the biomass and mortality tests of Eisenia fetida earthworms. The sewage sludge had a statistically significant impact on the increase in: electrical conductivity, total exchangeable cations, organic matter content, organic carbon, nitrogen and heavy metals of the considered soil. The impact on the biomass of earthworms was different; after 7 days in the mixtures with 3 Mg/ha and 6 Mg/ha sewage sludge addition, the biomass increased approximately by 1.3-fold, in comparison to non-modified soil. At 9 Mg/ha, it reduced by 1.3-fold, whereas at 15 Mg/ha – by 16-fold, in relation to the initial value. The studies indicated that the ecotoxicological assessment of wastes may be employed as environmental safety control measure of the sewage sludge application in agriculture.


2016 ◽  
Vol 2 (2) ◽  
pp. 37
Author(s):  
B.H. Prasetyo ◽  
N. Suharta ◽  
Subagyo H. ◽  
Hikmatullah Hikmatullah

Ultisols are a major group of marginal soils extensively found in the upland area of Indonesia. To better understand the potential of the Ultisols developed from claystone and sandstone in the Sasamba Integrated Economical Development Area in East Kalimantan, chemical and mineralogical characteristics of 27 Ultisols pedons consisting of 76 topsoil and 118 subsoil samples were investigated. Besides analysis and interpretation of data, relationships of several soil characteristics were constructed using simple regression. The results indicated that Ultisols showed acid to very acid reaction, had low content of organic matter and low base saturation. Soils generally exhibited net negative charge, and the point of zero charge was reached at pH 3.6. Both potential and available phosphates were low, and there was a trend that amorphous aluminum was responsible for phosphate fixation. The low content of exchangeable potassium in topsoil and subsoil indicated a positive correlation with potential potassium. Clay mineral was composed chiefly of kaolinite, with small amounts of illite, vermiculite, and quartz. The domination of kaolinite and low organic matter content causes the soils to have low cation exchange capacity. Soil management in this area should be focused on building up and maintaining soil fertility, and applying appropriate soil conservation techniques to minimize erosion. To obtain sustained productivity, various soil amendments including the use of farm and/or green manure, liming with agricultural lime, and application of rock phosphate and K fertilizers were highly recommended.


Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 337
Author(s):  
Hanane Sghiouri El Idrissi ◽  
Abderrahim Samaouali ◽  
Younes El Rhaffari ◽  
Salah El Alami ◽  
Yves Geraud

In this work, we study the variability of the lithological composition and organic matter content of samples were taken from the different layers M, X and Y of the Timahdit oil shale in Morocco, in order to experimentally analyze the impact of this variability on petrophysical measurements. The objective of this study is to predict the properties of the layers, including their thermal conductivity, thermal diffusivity, porosity and P and S wave velocities. The results of the study of the impact of the organic matter content of the samples on the petrophysical measurements show that, regardless of the organic matter content, thermal conductivity and diffusivity remain insensitive, while P and S wave velocities decrease linearly and porosity increases with increasing organic matter content. On the other hand, the study of the organic matter variability content is consistent with the velocity ratio, so can be used as an organic matter indicator of the layers. Conductivity and thermal diffusivity are almost invariant to the variability of the organic matter.


Soil Research ◽  
2016 ◽  
Vol 54 (1) ◽  
pp. 11 ◽  
Author(s):  
Melinda R. S. Moata ◽  
Ashlea L. Doolette ◽  
Ronald J. Smernik ◽  
Ann M. McNeill ◽  
Lynne M. Macdonald

Organic phosphorus (P) plays an important role in the soil P cycle. It is present in various chemical forms, the relative amounts of which vary among soils, due to factors including climate, land use, and soil type. Few studies have investigated co-variation between P types or stoichiometric correlation with the key elemental components of organic matter– carbon (C) and nitrogen (N), both of which may influence P pool structure and dynamics in agricultural soils. In this study we determined the organic P speciation of twenty Australian Red Chromosols soils, a soil type widely used for cropping in Australia. Eight different chemical forms of P were quantified by 31P NMR spectroscopy, with a large majority (>90%) in all soils identified as orthophosphate and humic P. The strongest correlations (r2 = 0.77–0.85, P < 0.001) between P types were found among minor components: (i) between two inositol hexakisphosphate isomers (myo and scyllo) and (ii) between phospholipids and RNA (both detected as their alkaline hydrolysis products). Total soil C and N were correlated with phospholipid and RNA P, but not the most abundant P forms of orthophosphate and humic P. This suggests an influence of organic matter content on the organic P pool consisting of phospholipid and RNA, but not on inositol P or the largest organic P pool in these soils – humic P.


1998 ◽  
Vol 16 (8) ◽  
pp. 583-594 ◽  
Author(s):  
Dhirendra Singh

The effect of exchangeable cations (H+ and Na+). autoclaving, organic matter, anionic surfactants and temperature on the adsorption of phosphamidon on two different types of Indian soil was studied. The adsorption isotherms for all the effects/treatments were in close agreement with the Freundlich equation and yielded S-shaped isotherms. The amount of phosphamidon adsorbed in all cases was higher in medium black (silt loam) soil than alluvial soil (sandy loam) and was related to the organic matter content, clay content, CaCO3 content, surface area and cation-exchange capacity of the soils. The adsorption on both types of soil follows the order H+-soil > Na+-soil > natural soil at 10°C > natural soil at 20°C > autoclaved soil > organic matter-removed soil > anionic surfactant > natural soil at 40°C, which was in accordance with the Freundlich constant, KF, and distribution coefficient, Kd, values. The adsorption capacity of phosphamidon for organic matter and clay content for both the soils was evaluated by calculating the Kom and Kc values when it was found that phosphamidon adsorption was better correlated with the clay content than with the orgnic matter content on the basis of adsorption isotherms. Various thermodynamic parameters such as the thermodynamic equilibrium constant (K0), the standard free energy (ΔG0), the standard enthalpy (ΔH0) and the standard entropy (ΔS0) changes have been calculated as a means of predicting the nature of the isotherms.


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