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Search Results: 1 - 10 of 13607 matches for " soil "
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Impacts of Forest Harvest on Active Carbon and Microbial Properties of a Volcanic Ash Cap Soil in Northern Idaho  [PDF]
Deborah S. Page-Dumroese, Matt D. Busse, Steven T. Overby, Brian D. Gardner, Joanne M. Tirocke
Open Journal of Soil Science (OJSS) , 2015, DOI: 10.4236/ojss.2015.51002
Abstract: Soil quality assessments are essential for determining impacts on belowground microbial community structure and function. We evaluated the suitability of active carbon (C), a rapid field test, as an indicator of soil biological quality in five paired forest stands (clear cut harvested 40 years prior and unharvested) growing on volcanic ash-cap soils in northern Idaho. Active C was compared with several traditional measures of soil microbial properties (microbial biomass, respiration, fungal hyphal biomass, bacterial number and biomass and PLFA community structure). Despite the significant differences in forest vegetation between paired stands, no differences in active C and only a few significant differences in microbial properties were detected. Total bacteria (microscope counts) and PLFA signatures (gram positive bacteria, gram negative bacteria, actinomycetes) were significantly higher in the managed stands. Our results indicate that either mineral soil biological properties in managed stands were relatively unaffected at the time of harvest or some biological recovery occurred 40 years later. Additionally, volcanic ash-cap soils in moist ecosystems could be highly resilient to the impacts of harvest operations and therefore few significant biological changes could be detected.
Morphological, Physical and Chemical Characteristics of Hill Forest Soils at Chittagong University, Bangladesh  [PDF]
Md. Akhtaruzzaman, Md. Enamul Haque, Khan Towhid Osman
Open Journal of Soil Science (OJSS) , 2014, DOI: 10.4236/ojss.2014.41004

Forty five soil samples were collected from the four pedons of the hill areas at Chittagong University based on the depth of soil horizon. Soil profiles on hill top were relatively well developed and belonged to Ultisols according to USDA soil Taxonomy. The profiles at the piedmont were relatively young soils and classified as Inceptisols and Entisols. The soils of all profiles were characterized by coarse texture (38% to 73%, sand fraction), high bulk density (1.15 to 1.32 Mg·m-3), low organic-C content (0.26% to 1.73%), acid soil reaction ( varied from 4.44 to 5.52 and pHKCl from 3.57 to 4.90). Soils in all pedons were poor in exchangeable bases and base saturation. The CEC values ranged from 9.12 cmolc·kg-1 to 14.5 cmolc·kg-1 while ECEC varied from 1.96 to 4.78 cmolc·kg-1. The exchangeable Al (aluminum) concentration ranged from 0.41 to 0.66 cmolc·kg-1. Exchangeable acidity level ranged from 0.74 to 1.25 cmolc·kg-1. Exchangeable Al and aluminum saturation increased with depth and their concentrations were below the toxic range for tree stands. The study revealed that more young soils formed on the piedmont sites had somewhat better properties as compared to matured hill top soils. The variation in physico-chemical properties of the soils seemed to be influenced by the topography to a greater extent in the studied area.

Microbe—Chloroacetanilide Herbicide Interaction across Soil Type  [PDF]
Sutapa Paul, Arunabha Chakravarty, Prasanta Kumar Patra, Niladri Paul, Premasis Sukul, Debatosh Mukherjee
Open Journal of Soil Science (OJSS) , 2015, DOI: 10.4236/ojss.2015.54009
Abstract: An investigation was carried out under laboratory conditions to study the persistence of butachlor applied at recommended dose (2 kg ai/ha) along with its impact on microbial activity as well as growth of colonial bacteria and fungi in alluvial (Typic Haplaquent), lateritic (Typic Haplustalf) and coastal (Typic Haplaquept) soils. Butachlor caused a significant increment in microbial activity following an initial diminution in between 10 to 22 days of incubation depending on the type of soil. The herbicide resulted in a significant shrinkage in bacterial community during later stages of incubation in lateritic and coastal soils in spite of a significant swelling on the 15th day in lateritic and alluvial soils. Fungal community significantly expanded at the initial stage in lateritic soil and during later stages in alluvial soil by the application of butachlor but shriveled during later stages in the lateritic soil, intermediate stage in coastal soil and initial stages in alluvial soil. Alluvial soil reared the highest population of colonial bacteria and exhibited highest microbial activity while coastal soil significantly pressed them down to the lowest. However, lateritic soil was the best niche for fungal community. Co-metabolism was the main phenomenon in butachlor metabolism particularly in coastal soil, though zymogenous microbes including bacteria and fungi also participated in both lateritic and alluvial soil at certain stages. The persistence of butachlor was the lowest in alluvial soil followed by lateritic and coastal soil, respectively. Among the soil types application of butachlor is safe in alluvial soil.
Copper Phytoextraction and Phytostabilization by Brachiaria decumbens Stapf. in Vineyard Soils and a Copper Mining Waste  [PDF]
Robson Andreazza, Leandro Bortolon, Simone Pieniz, Flávio A. O. Camargo, Elisandra Solange Oliveira Bortolon
Open Journal of Soil Science (OJSS) , 2013, DOI: 10.4236/ojss.2013.36032
Abstract: Brachiaria decumbens is a high biomass plant with great potential for phytoremediation of copper-polluted soils. The current study aimed to evaluate B. decumbens plants for phytoextraction and phytostabilization use in two different copper contaminated vineyard soils and a copper mining waste. Also, the macro and micronutrients uptake were evaluated after plants growth in copper contaminated soils. B. decumbens was cultivated in two vineyard soils (Inceptisol and Mollisol) and a copper mining waste for 47 days of growth in greenhouse. Then, B. decumbens’s nutrient uptake was evaluated, and it’s potential application in phytoremediation techniques for the phytoextraction and phytostabilization of copper contamination. B. decumbens exhibited high levels of biomass production at contaminated soils and no negative effect on macronutrients uptake was found. Copper contaminated soils affected micronutrients uptake by Brachiaria plants. This Brachiaria specie showed high potential on copper phytoextraction with accumulation of copper concentrations in the shoots and roots of 70 and 585 mg·kg-1 of dry mass, respectively, in the vineyard Inceptisol soil, after 47 days of growth. Mollisol soil and copper mining waste also exhibited high copper concentration in the biomass in the entire plant with 371 and 466 mg·kg-1, respectively. Although Brachiaria exhibited low levels of translocation factor for copper, this specie showed high potential for copper phytoextraction on Inceptisol, Mollisol and copper mining waste with 1900, 1156 and 1363 g·ha-1 of copper, respectively. In summary, B. decumbens plants showed high potential for copper phytoextraction and phytostabilization of copper on contaminated vineyard soils and copper mining waste
Switchgrass Management Practice Effects on Near-Surface Soil Properties in West-Central Arkansas  [PDF]
Alayna Jacobs, Kristofor R. Brye, Randy King, Joel Douglas, Lisa S. Wood, Larry C. Purcell, Michael Looper
Open Journal of Soil Science (OJSS) , 2015, DOI: 10.4236/ojss.2015.53008
Abstract: Agronomic management practices that maximize monoculture switchgrass (Panicum virgatum L.) yield are generally well understood; however, little is known about corresponding effects of differing switchgrass management practices on near-surface soil properties and processes. The objective of the study was to evaluate the effects of cultivar (“Alamo” and “Cave-in-Rock”), harvest frequency (1- and 2-cuts per year), fertilizer source (poultry litter and commercial fertilizer), and irrigation management (irrigated and non-irrigated) on near-surface soil properties and surface infiltration in a Leadvale silt loam (fine-silty, siliceous, semiactive, thermic, Typic Fragiudult) after four years (2008 through 2011) of consistent management in west-central Arkansas. Irrigating switchgrass increased (P < 0.01) soil bulk density in treatment combinations where poultry litter was applied (1.40 g?cm?3) compared to non-irrigated treatment combinations (1.33 g?cm?3). Root density was greater (P = 0.031) in irrigated (2.62 kg?cm?3) than in non-irrigated (1.65 kg?cm?3) treatments when averaged over all other treatment factors. The total infiltration rate under unsaturated conditions was greater (P = 0.01) in the 1-cut (33 mm?min?1) than 2-cut (23 mm?min?1) harvest treatment combinations when averaged over all other treatment factors, while the total infiltration rate under saturated conditions did not differ among treatment combinations (P > 0.05) and averaged 0.79 mm?min?1. Results from this study indicate that management decisions to maximize switchgrass biomass production affect soil properties over relatively short periods of time, and further research is needed to develop local best management practices to maximize yield while maintaining or improving soil quality.
Climate Smart Agriculture: Achievements and Prospects in Africa  [PDF]
Adornis D. Nciizah, Isaiah I. C. Wakindiki
Journal of Geoscience and Environment Protection (GEP) , 2015, DOI: 10.4236/gep.2015.36016

Smallholder agriculture is facing a myriad of challenges in the wake of a changing climate. To counter this, several measures have been suggested in attempts to reduce the vulnerability of smallholder farmers who are the worst affected by changes in climate. However, despite these interventions not much improvement in agricultural production has been realized by the smallholder farmers. This suggests the need for more alternative options for these resource poor farmers. One such intervention is climate smart agriculture (CSA), which is probably one of the most viable and sustainable options. It offers both mitigation and adaptation measures to climate changes. However, problems of its viability and sustainability have been raised by several authors who argue that there are barriers, limits and costs, which may hinder its adoption by farmers. This review discusses the achievements attained so far in improving the productivity of smallholder agricultural soils under changing climatic conditions. The review also looks at the prospect of CSA with regards to South African smallholder agriculture.

Role of Biochar Amendment on Soil Carbon Mineralization and Microbial Biomass  [PDF]
Yimin Wang, Ming Li
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.611013
To understand the influence of biochar properties (pyrolysis temperature and types) on soil physicochemical properties, we investigated the changes of soil organic carbon mineralization, nutrient contents and microbial biomass after 135 d incubation. Results showed that both corn straw (CB) and rice straw (RB) derived biochars increase the mineralization of organic carbon and nitrogen in the soil, and these biochars pyrolysised at 500?C (CB500, RB500) significantly enhanced the mineralization of soil organic nitrogen. In comparison with control treatment, the application of biochar significantly increased the contents of soil organic carbon, available P and K in soil. Moreover, the activity of soil microbe was enhanced with biochar amendment. Among all treatments, RB500 significantly increased the content of soil microbial biomass carbon (379 ± 9 mg?kg?1) in soil. Our results suggested that the application of biochars to soil improve soil quality, while the biochar type and pyrolysis temperature should be taken into consideration before its application in agro-ecosystem.
A Soil Quality Index to Evaluate the Vermicompost Amendments Effects on Soil Properites  [PDF]
Romina Romaniuk, Lidia Giuffré, Rosario Romero
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.25058
Abstract: The aims of this work were 1) to evaluate the changes in soil properties with the application of different amounts of vermicompost (10 and 20 Mg?ha–1), and 2) to construct a soil quality index that allows the evaluation of changes in the most sensitive soil parameters. The study was carried out in a cattle field of General Alvear, Buenos Aires, Argentina. Vermicompost application showed a positive effect on most of the chemical and biological soil properties evaluated, especially with the higher dose (20 Mg?ha–1). There were slight but significant increases in electrical conductivity and soil pH with the higher dose of vermicompost. Physical soil properties were not affected by the vermicompost amendment. The SQI showed a significant increase of soil quality with the vermicompost dose of 20 Mg?ha–1, especially by enhancing the biochemical and biological properties.
A New Approach for Atrazine Desorption, Extraction and Detection from a Clay-Silty Soil Sample  [PDF]
Rossy Feria-Reyes, Paola Medina-Armenta, M. Teutli-León, M. G. García-Jiménez, I. González
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.228125
Abstract: This paper reports an alternative method for extraction, detection and quantification of atrazine from a clay-silty soil. Atrazine adsorption isotherm for this kind of soil fits to a Freundlich adsorption isotherm with a correlation coefficient of 0.994, sorption intensity 1/n = 0.718 and Kf = 1, with a maximum soil adsorbed atrazine concentration of 8 mg g–1. Atrazine desorption was approached using several surfactants including non-ionic (Triton X-100, Triton X-114, and Triton X-405), anionic (SDS) and cationic (CTAB), these surfactants were used at critical micellar concentration (CMC) and higher concentrations. Atrazine quantification was done by high resolution liquid chromatography coupled to spectrophotometric detection (HPLC-UV), optimized conditions correspond to a flow rate of 1.0 mL min–1, λ = 260 nm, a C18 PAH Agilent-Eclipse column with a mobile phase of CH3OH/1 × 10–3, a phosphate buffer, pH 3.2/CH3CN 55:30:15 (v/v). At these conditions it can be obtained a good chromatographic separation of atrazine and soil organic matter. Atrazine desorption was aided by surfactants at CMC conditions, it can be claimed that atrazine desorption was enhanced by surfactants since desorption, from higher to lower, goes as follows: 98.5% with Triton X-114, 98% with SDS, 89.5% with Triton X-405, 86.5% with Triton X-100; and 45% with CTAB.
System for High Throughput Water Extraction from Soil Material for Stable Isotope Analysis of Water  [PDF]
Timothy S. Goebel, Robert J. Lascano
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2012, DOI: 10.4236/jasmi.2012.24031

A major limitation in the use of stable isotope of water in ecological studies is the time that is required to extract water from soil and plant samples. Using vacuum distillation the extraction time can be less than one hour per sample. Therefore, assembling a distillation system that can process multiple samples simultaneously is advantageous and necessary for ecological or hydrological investigations. Presented here is a vacuum distillation apparatus, having six ports, that can process up to 30 samples per day. The distillation system coupled with the Los Gatos Research DLT-100 Liquid Water Isotope Analyzer is capable of analyzing all of the samples that are generated by vacuum distillation. These two systems allow larger sampling rates making investigations into water movement through an ecological system possible at higher temporal and spatial resolution.

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