Organic matter fractionation in aggregates typical Argiudolls southeastern Buenos Aires and its relation to different soil uses: a preliminary study

2011 ◽  
Vol 65 (2) ◽  
pp. 505-515 ◽  
Author(s):  
Maria Fernanda Alvarez ◽  
Margarita Luisa Osterrieth ◽  
Julio Luis del Río
Keyword(s):  
Organic Matter ◽  
Buenos Aires ◽  
Organic Matter Fractionation ◽  
Preliminary Study

Fine-root distribution of coniferous plantations in relation to site in southern Buenos Aires, Argentina

1992 ◽  
Vol 22 (11) ◽  
pp. 1575-1582 ◽  
Author(s):  
Adrián Ares ◽  
Norman Peinemann
Keyword(s):  
Organic Matter ◽  
Vertical Distribution ◽  
Root Distribution ◽  
Fine Roots ◽  
Buenos Aires ◽  
Fine Root ◽  
Organic Matter Content ◽  
Root Density ◽  
Site Quality ◽  
Coniferous Plantations

A study was conducted to determine the amounts and vertical distribution of fine roots <2 mm as a function of site quality in a temperate, hilly zone of Argentina. Fine roots were sampled in autumn from 0.2-ha plots established in 12 coniferous plantations of Pinushalepensis Mill., Pinusradiata D. Don, Cedrusdeodara (D. Don) G. Don, and Cupressussempervirens L.f. horizontalis, located in Sierra de la Ventana, southern Buenos Aires. Generally, root density was found to be higher under low-growth stands. The distance from a tree sometimes had an effect on root density, but no clear pattern within stands could be observed. Root density commonly decreased with depth, but slight irregularities in some profiles were observed. Site quality and soil type influenced root distribution. Belowground biomass up to a depth of 50 cm ranged from 1600 to 9800 kg•ha−1 in high-growth stands and from 5400 to 40 700 kg•ha−1 in low-growth stands. Soil organic matter content provided the best correlation with root density. A possible practical implication would be the use of indices related to vertical distribution of organic matter, among other variables, as complementary estimators of effective depth of rooting. The results strongly suggest that trees maintain a large fine-root system in poor sites at the expense of aboveground growth.

scholarly journals Galls of Cecidoses eremita Curtis and Eucecidoses minutanus Brèthes (Lepidoptera: Cecidosidae) in Magdalena, Buenos Aires Province: preliminary study and associated fauna

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Veronica Loetti ◽  
Alejandra Valverde ◽  
Diana Nora Rubel
Keyword(s):  
Wall Thickness ◽  
Buenos Aires ◽  
Maximum Diameter ◽  
Buenos Aires Province ◽  
Associated Fauna ◽  
The Family ◽  
Preliminary Study

Abstract In Argentina, five galling species of the family Cecidosidae (Lepidoptera), including Cecidoses eremita Curtis and Eucecidoses minutanus Brèthes, have been cited. This note reports a preliminary study of their galls in "molles" (Schinus longifolius (Lindl.) Speg.) of Magdalena (Buenos Aires, Argentina). In April 2013, galls of C. eremita and E. minutanus were censused in randomly selected "molles". In April and December 2013, randomly selected galls were then collected and transported to our laboratory in hermetic bags, and conserved at -18 ºC until examination. Maximum diameter and wall thickness of collected galls were measured. About 84% of the observed "molles" (103/123) had galls of C. eremita and/or E. minutanus. The median of galls per tree was 12 (Q1=6; Q3=22). Eucecidoses minutanus had galls with smaller diameter (U11;53= 583; P<0.05) and thinner wall (U10;52=506.5; P<0..05) than C. eremita. In open galls, we found Pseudoescorpionida, Araneae (Segestriidae and Salticidae), and larvae of Lepidoptera and Hymenoptera. Within closed galls, we found adults of Torymidae and Chalcidoidea, and larvae of Ichneumonoidea.

scholarly journals PERSISTENCE OF ATRAZINE, METRIBUZIN AND SIMAZINE HERBICIDES IN TWO SOILS

1999 ◽  
Vol 34 (11) ◽  
pp. 2037-2044 ◽  
Author(s):  
FEDERICO FUSCALDO ◽  
FRANCISCO BEDMAR ◽  
GLORIA MONTERUBBIANESI
Keyword(s):  
Organic Matter ◽  
Active Ingredient ◽  
Buenos Aires ◽  
Dry Weight ◽  
Buenos Aires Province ◽  
High Ph ◽  
Dry Soil ◽  
Soil Weight

An oat bioassay was conducted in pots under greenhouse conditions to determine the persistence of atrazine, metribuzin and simazine herbicides in soils of the southeast of Buenos Aires Province, Argentina. Atrazine rates of 0, 0.58, 1.16 and 2.32 mug g-1 of active ingredient (a.i.), metribuzin rates of 0, 0.14, 0.28 and 0.56 mug g-1 of a.i., and simazine rates of 0, 0.72, 1.45 and 2.9 mug g-1 of a.i. dry soil weight were applied to pots containing soils from Balcarce and San Cayetano sites. Organic matter (OM) content and pH of Balcarce soil were 5.5% and 5.8%, while for San Cayetano soil were 2.9% and 6.7%, respectively. Relative dry weight (RDW) of oat shoots was calculated as percentage of control. Considering a 20% RDW reduction of oat shoots, persistences of recommended rates for the region were: atrazine (1.16 mug g-1 of a.i.), 78 and 130 days after treatment (DAT) for Balcarce and San Cayetano soil, respectively; metribuzin (0.28 mug-1 of a.i.), 63 and 77 DAT for Balcarce and San Cayetano soil, respectively; simazine (1.45 mug g-1 of a.i.), 81 and 156 DAT for Balcarce and San Cayetano soil, respectively. Results show that persistence of atrazine, metribuzin and simazine in soil increased with high rates, low OM content and high pH.

Removal of Pollutants in Different Landfill Leachate Treatment Processes on the Basis of Organic Matter Fractionation

2018 ◽  
Vol 47 (2) ◽  
pp. 297-305 ◽  
Author(s):  
Mehdi Zolfaghari ◽  
Oumar Dia ◽  
Nouha Klai ◽  
Patrick Drogui ◽  
Satinder Kaur Brar ◽  
...  
Keyword(s):  
Organic Matter ◽  
Landfill Leachate ◽  
Leachate Treatment ◽  
Treatment Processes ◽  
Organic Matter Fractionation

scholarly journals Plastic Accumulation in the Sea Surface Microlayer: An Experiment-Based Perspective for Future Studies

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 66 ◽  
Author(s):  
Luisa Galgani ◽  
Steven Loiselle
Keyword(s):  
Organic Matter ◽  
Marine Environment ◽  
Bulk Water ◽  
Sea Surface ◽  
Surface Microlayer ◽  
Surface Ocean ◽  
Marine Organic Matter ◽  
Sea Surface Microlayer ◽  
Preliminary Study ◽  
The Impact

Plastic particles are ubiquitous in the marine environment. Given their low density, they have the tendency to float on the sea surface, with possible impacts on the sea surface microlayer (SML). The SML is an enriched biofilm of marine organic matter, that plays a key role in biochemical and photochemical processes, as well as controlling gas exchange between the ocean and the atmosphere. Recent studies indicate that plastics can interfere with the microbial cycling of carbon. However, studies on microplastic accumulation in the SML are limited, and their effects on organic matter cycling in the surface ocean are poorly understood. To explore potential dynamics in this key ocean compartment, we ran a controlled experiment with standard microplastics in the surface and bulk water of a marine monoculture. Bacterial abundance, chromophoric dissolved organic matter (CDOM), and oxygen concentrations were measured. The results indicate an accumulation of CDOM in the SML and immediate underlying water when microplastic particles are present, as well as an enhanced oxygen consumption. If extrapolated to a typical marine environment, this indicates that alterations in the quality and reactivity of the organic components of the SML could be expected. This preliminary study shows the need for a more integrated effort to our understanding the impact of microplastics on SML functioning and marine biological processes.

Comparison of different soil organic matter fractionation methodologies: Evidences from ultrasensitive 14C measurements

2010 ◽  
Vol 268 (7-8) ◽  
pp. 1062-1066 ◽  
Author(s):  
Fabio Marzaioli ◽  
Carmine Lubritto ◽  
Ilaria Del Galdo ◽  
Antonio D’Onofrio ◽  
M. Francesca Cotrufo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Matter Fractionation

Acid Drainage and Metal Bioleaching by Redox Potencial Changes in Heavy Polluted Fluvial Sediments

2013 ◽  
Vol 825 ◽  
pp. 496-499 ◽  
Author(s):  
Natalia Porzionato ◽  
Mariangeles Mellota ◽  
Roberto Candal ◽  
Gustavo Curutchet
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Redox Potential ◽  
Buenos Aires ◽  
Urban Streams ◽  
Fluvial Sediments ◽  
Metal Release ◽  
Human Disturbances ◽  
Anaerobic Sediments ◽  
Acidification Potential

Sediments from polluted urban streams act as a sink of contaminants. The high content of organic matter and sulphides makes the system appropriate for binding heavy metals. However, changes in the redox potential leads to processes in which sediments acts like a low sulphidic ore in an oxidizing environment, and could generate acid drainages. Human and not human disturbances of the sediments could derive in its oxidation catalyzed by sulphur oxidizing bacteria (SOB). This process leads to acidification and metal release. In this study we analyze the acidification potential of anaerobic sediments of polluted streams near Buenos Aires with static and kinetic methods. The results remark the necessity to consider this process before any sediment management action.

scholarly journals Preliminary Study on Physico-Chemical Parameters and Phytoplankton of Chiffa River (Blida, Algeria)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Fella Hamaidi-Chergui ◽  
Mohamed Brahim Errahmani ◽  
Fatouma Benouaklil ◽  
Mohand Said Hamaidi
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Organic Matter ◽  
Water Samples ◽  
Chemical Parameters ◽  
North West ◽  
Quality Guidelines ◽  
Physico Chemical ◽  
Preliminary Study ◽  
Monthly Variations

The present study was carried out to determine the monthly variations of physico-chemical parameters in water samples from Chiffa river at Blida, North West of Algeria from April to August 2006. Water samples were analyzed for physico-chemical parameters and the results showed their monthly variations as follows: pH 7.5-7.6, electrical conductivity 0.87–1.06 mS·cm−1, nitrate 0–7.00 mg·L−1, nitrite 0–0.28 mg·L−1, ammonia 0–0.03 mg·L−1, phosphate 0–0.94 mg·L−1, sodium 19.3–47.0 mg·L−1, chloride 35.7–52.0 mg·L−1, calcium 90.3–104.7 mg·L−1, magnesium 27.3–37.7 mg·L−1, organic matter 0.4–3.9 mg·L−1, chlorophyll a 0.7–132.3 mg·L−1, and bicarbonate 219.3–248.7 mg·L−1. The analyzed physico-chemical parameters were almost not exceeded the maximum permissible limit of WHO and Algerian Water Quality Guidelines. A total of 53 taxa belonging to 4 divisions have been identified, including Chlorophyta (52.83% of taxa), Bacillariophyta (28.30%), Cyanophyceae (16.98%), and Charophyta (1.89%).

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