scholarly journals Short-term changes in soil Munsell colour value, organic matter content and soil water repellency after a spring grassland fire in Lithuania

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 209-225 ◽  
Author(s):  
P. Pereira ◽  
X. Úbeda ◽  
J. Mataix-Solera ◽  
M. Oliva ◽  
A. Novara

Abstract. Fire is a natural phenomenon with important implications on soil properties. The degree of this impact depends upon fire severity, the ecosystem affected, topography of the burned area and post-fire meteorological conditions. The study of fire effects on soil properties is fundamental to understand the impacts of this disturbance on ecosystems. The aim of this work was to study the short-term effects immediately after the fire (IAF), 2, 5, 7 and 9 months after a low-severity spring boreal grassland fire on soil colour value (assessed with the Munsell colour chart), soil organic matter content (SOM) and soil water repellency (SWR) in Lithuania. Four days after the fire a 400 m2 plot was delineated in an unburned and burned area with the same topographical characteristics. Soil samples were collected at 0–5 cm depth in a 20 m × 20 m grid, with 5 m space between sampling points. In each plot 25 samples were collected (50 each sampling date) for a total of 250 samples for the whole study. SWR was assessed in fine earth (< 2 mm) and sieve fractions of 2–1, 1–0.5, 0.5–0.25 and < 0.25 mm from the 250 soil samples using the water drop penetration time (WDPT) method. The results showed that significant differences were only identified in the burned area. Fire darkened the soil significantly during the entire study period due to the incorporation of ash/charcoal into the topsoil (significant differences were found among plots for all sampling dates). SOM was only significantly different among samples from the unburned area. The comparison between plots revealed that SOM was significantly higher in the first 2 months after the fire in the burned plot, compared to the unburned plot. SWR of the fine earth was significantly different in the burned and unburned plot among all sampling dates. SWR was significantly more severe only IAF and 2 months after the fire. In the unburned area SWR was significantly higher IAF, 2, 5 and 7 months later after than 9 months later. The comparison between plots showed that SWR was more severe in the burned plot during the first 2 months after the fire in relation to the unburned plot. Considering the different sieve fractions studied, in the burned plot SWR was significantly more severe in the first 7 months after the fire in the coarser fractions (2–1 and 1–0.5 mm) and 9 months after in the finer fractions (0.5–0.25 and < 0.25 mm). In relation to the unburned plot, SWR was significantly more severe in the size fractions 2–1 and < 0.25 mm, IAF, 5 and 7 months after the fire than 2 and 9 months later. In the 1–0.5- and 0.5–0.25 mm-size fractions, SWR was significantly higher IAF, 2, 5 and 7 months after the fire than in the last sampling date. Significant differences in SWR were observed among the different sieve fractions in each plot, with exception of 2 and 9 months after the fire in the unburned plot. In most cases the finer fraction (< 0.25 mm) was more water repellent than the others. The comparison between plots for each sieve fraction showed significant differences in all cases IAF, 2 and 5 months after the fire. Seven months after the fire significant differences were only observed in the finer fractions (0.5–0.25 and < 0.25 mm) and after 9 months no significant differences were identified. The correlations between soil Munsell colour value and SOM were negatively significant in the burned and unburned areas. The correlations between Munsell colour value and SWR were only significant in the burned plot IAF, 2 and 7 months after the fire. In the case of the correlations between SOM and SWR, significant differences were only identified IAF and 2 months after the fire. The partial correlations (controlling for the effect of SOM) revealed that SOM had an important influence on the correlation between soil Munsell colour value and SWR in the burned plot IAF, 2 and 7 months after the fire.

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 291 ◽  
Author(s):  
Francisco J. Moral Garcíía ◽  
Louis W. Dekker ◽  
Klaas Oostindie ◽  
Coen J. Ritsema

The occurrence and consequences of fire-induced water repellency have been studied in several regions of Spain since 1989. The occurrence of water repellency formed under natural conditions, however, has only been described for a few areas in Spain since 1998. The purpose of the present study was to investigate the severity of naturally occurring water repellency in the sandy soils of the Natural Park of Doñana in southern Spain. The persistence and degree of soil water repellency were measured on field-moist and dried sandy soil samples taken beneath Pinus pinea trees. Around 50% of the field-moist soil samples taken at 0–0.10 m depths exhibited (actual) water repellency. Potential water repellency, measured after drying the samples at 60°C, showed for 68% of the samples slight to extreme water repellency. The organic matter content was found to be positively correlated with persistence and with degree of potential water repellency.


2014 ◽  
Vol 62 (4) ◽  
pp. 309-315 ◽  
Author(s):  
D.A.L. Leelamanie

Abstract The wetting rate of soil is a measure of water repellency, which is a property of soils that prevents water from wetting or penetrating into dry soil. The objective of the present research was to examine the initial water repellency of organic manure amended soil, and its relation to the soil organic matter (SOM) depletion rates in the laboratory. Soil collected from the Wilpita natural forest, Sri Lanka, was mixed with organic manure to prepare soil samples with 0, 5, 10, 25, and 50% organic manure contents. Locally available cattle manure (CM), goat manure (GM), and Casuarina equisetifolia leaves (CE) were used as the organic manure amendments. Organic matter content of soils was measured in 1, 3, 7, 14, and 30 days intervals under the laboratory conditions with 74±5% relative humidity at 28±1°C. Initial water repellency of soil samples was measured as the wetting rates using the water drop penetration time (WDPT) test. Initial water repellency increased with increasing SOM content showing higher increasing rate for hydrophobic CE amended samples compared with those amended with CM and GM. The relation between water repellency and SOM content was considered to be governed by the original hydrophobicities of added manures. The SOM contents of all the soil samples decreased with the time to reach almost steady level at about 30 d. The initial SOM depletion rates were negatively related with the initial water repellency. However, all the CE amended samples initially showed prominent low SOM depletion rates, which were not significantly differed with the amended manure content or the difference in initial water repellency. It is explicable that the original hydrophobicity of the manure as well has a potentially important effect on initiation of SOM decomposition. In contrast, the overall SOM depletion rate can be attributed to the initial water repellency of the manure amended sample, however, not to the original hydrophobicity of the amended manure. Hydrophobic protection may prevent rapid microbial decomposition of SOM and it is conceivable that hydrophobic substances in appropriate composition may reduce organic matter mineralization in soil. These results suggest the contribution of hydrophobic organic substances in bioresistance of SOM and their long-term accumulation in soils


Author(s):  
Trina Stephens

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.


Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.


2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan

Sequential extractions, metal uptake by <i>Taraxacum officinale</i>, Ruby&rsquo;s physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (<i>P</i> < 0.05). Statistically highly significant correlations (<i>P</i> < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (<i>R</i><sup>2</sup> = 69%). No highly significant correlations (<i>P</i> < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.


2009 ◽  
Vol 6 (3) ◽  
pp. 245 ◽  
Author(s):  
Achouak El Arfaoui ◽  
Stéphanie Sayen ◽  
Eric Marceau ◽  
Lorenzo Stievano ◽  
Emmanuel Guillon ◽  
...  

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.


Weed Science ◽  
1983 ◽  
Vol 31 (3) ◽  
pp. 368-372 ◽  
Author(s):  
Josef Kozak ◽  
Jerome B. Weber

Adsorption of five phenylurea herbicides, metobromuron [3-(p-bromophenyl)-1-methoxy-1-methylurea], monolinuron [3-(p-chlorophenyl)-1-methoxyl-1-methylurea], linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], chlorbromuron [3-(4-bromo-3-chlorophenyl)-1-methoxy-1-methylurea], and CGA-15646 [3-(3-chloro-4-methylphenyl)-1,1-dimethylurea] by eight selected soils of Czechoslovakia were studied. Constants from Freundlich and Langmuir equations were calculated and correlated with the major soil properties. Freundlich K values ranged from 1.84 to 128, and the Freundlich equation was better fitted to the adsorption isotherms than was the Langmuir equation. Soil organic-matter content was the most important factor influencing the range of adsorption.


1974 ◽  
Vol 54 (1) ◽  
pp. 7-14 ◽  
Author(s):  
L. S. CROSSON ◽  
R. PROTZ

Many soil mapping units (MU) have not been adequately sampled to provide a true measure of their variability; therefore, their descriptions must be regarded as incomplete, and valid statistical comparisons cannot be made with other closely related MU. The number of samples required to detect the differences in means of 18 soil properties between Brantford and Beverly Silt Loam MU were calculated and they ranged from 4 at the 80% probability level (10 at the 95% probability level) for organic matter content of the Ap horizon to several thousand for pH of the Ap horizon. Calculation of required sample numbers indicated that sufficient samples had been collected to make valid statistical comparisons between seven of the soil properties. All seven properties were found to be significantly different between the two MU at the 95% probability level. However, only two of the properties, hue and organic matter content of the Ap horizon, had distinctly different modal values between the two MU and neither of these properties is easily measured in the field. Therefore, it was concluded that the 18 soil properties examined were impractical and unreliable criteria for separating the MU in the field. But, the MU separations can be readily and validly made on the basis of landscape position.


2009 ◽  
Vol 33 (5) ◽  
pp. 1481-1488 ◽  
Author(s):  
Vanusa Maria Feliciano Jacomino ◽  
Kerley Alberto Pereira de Oliveira ◽  
Maria Helena Tirollo Taddei ◽  
Maria Célia Siqueira ◽  
Maria Eleonora Deschamps Pires Carneiro ◽  
...  

Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and sandy one. These analyses included: solid waste classification, evaluation of organic matter content and of P, K, Ca, Mg, and Al concentrations and of the mineralogical composition. Natural radionuclides and metal concentrations in PG and soil samples were also measured. Phosphogypsum was classified as Class II A - Not Dangerous, Not Inert, Not Corrosive and Not Reactive. The organic matter content in the soil samples was low and potential acidity high. In the mean, the specific 226Ra activity in the phosphogypsum samples (252 Bq kg-1) was below the maximum level recommended by USEPA, which is 370 Bq kg-1 for agricultural use. In addition, this study verified that natural radionuclides and metals concentrations in PG were lower than in the clayey Oxisol of Sete Lagoas, Minas Gerais, Brazil. These results indicated that the application of phosphogypsum as soil amendment in agriculture would not cause a significant impact on the environment.


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