scholarly journals Degradación de hojarasca y aporte de nutrientes del manglar en la Laguna Mecoacán, Golfo de México

2018 ◽  
Vol 66 (2) ◽  
pp. 892 ◽  
Author(s):  
Jony R. Torres V. ◽  
Dulce Infante-Mata ◽  
Alberto J. Sánchez ◽  
Alejandro Espinoza-Tenorio ◽  
Everardo Barba
Keyword(s):  
Organic Matter ◽  
Gulf Of Mexico ◽  
Leaf Litter ◽  
Organic Matter Content ◽  
Nutrient Supply ◽  
Matter Content ◽  
Avicennia Germinans ◽  
Water Flooding ◽  
Litter Degradation ◽  
Highly Correlated

Leaf litter degradation and nutrient supply in the mangroves of Mecoacán Lagoon, Gulf of Mexico. Mangroves are ecosystems with a high primary productivity that is mainly driven mainly by degradation processes. Energy (nutrients) flows from mangroves toward adjacent zones and the surrounding aquatic environment. The objective of the present study was to estimate the daily degradation coefficient (k) of mangrove leaves in relation to physical-chemical soil factors and in situ nutrient supply (phosphorus and nitrogen) in Mecoacán Lagoon, Gulf of Mexico. Leaf litter degradation bags were placed at six monthly monitoring sites to evaluate degradation and to calculate the corresponding degradation coefficients. A rapid degradation of up to 51 % was observed for Avicennia germinans (L.) Stearn during the first month in association with leaching resulting from flood conditions. The degradation of Rhizophora mangle (L.) (k= 0.0052±0.0002) (F= 12.2 p< 0.05 n= 216) and Laguncularia racemosa (L.) Gaertn (k= 0.005±0.0003) (F= 3.7 p= 0.2 n= 108), differed significantly from that of A. germinans (k= 0.009 ± 0.0003) (F= 1.2 p= 0.2 n= 216) did not present significant differences. To reach T50 degradation, R. mangle and L. racemosa required more time (133 and 138 days, respectively) than A. germinans (74 days). Organic matter and soil humidity were significantly correlated with the decay constant of A. germinans (r= 0.65 p< 0.05 and r= 0.55 p< 0.05, respectively). Total nitrogen content was highest in the Pajaral site (2 683 mg.kg) and was also highly correlated with organic matter content (r= 0.9 p= 0.003). Total phosphorus content was highest in the Boca site (2 031 mg.kg) and was also negatively correlated with pH (r= -0.61 p= 0.004). In conclusion, differences in the rate of mangrove leaf degradation depend on the involved species (leaf composition), time of exposure or immersion in water (flooding patterns) and sediment heterogeneity (i.e., texture, pH, humidity content and bulk density). Rev. Biol. Trop. 66(2): 892-907. Epub 2018 June 01. 

Adsorption and Efficacy of Trifluralin and Butralin as Influenced by Soil Properties

Weed Science ◽  
1985 ◽  
Vol 33 (6) ◽  
pp. 861-867 ◽  
Author(s):  
C. John Peter ◽  
Jerome B. Weber
Keyword(s):  
Organic Matter ◽  
Weed Control ◽  
Organic Matter Content ◽  
Soil Surface ◽  
Matter Content ◽  
Soil Adsorption ◽  
Glycol Monoethyl Ether ◽  
Chamber Studies ◽  
Highly Correlated ◽  
Growth Chamber Studies

Significantly higher rates of butralin [4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamine] were required to produce the same level of weed control as trifluralin [2,6-dinitro -N,N-dipropyl-4-(trifluoromethyl) benzenamine] when applied to soybeans [Glycine max(L.) Merr.] on seven different soils in the field. Higher rates of butralin were also required to control barnyardgrass [Echinochloa crus-galli(L.) Beauv. ♯ ECHCG] in growth chamber studies. No differences in the extent of soil adsorption of trifluralin and butralin were apparent; therefore, differences in efficacy could not be attributed to differences in soil adsorption. Herbicide rates required for 80% weed control and Freundlich K-values (adsorption capacity indices) were mostly highly correlated with soil organic-matter content and soil surface area as measured by benzyl ethyl ether (BEE) and ethylene glycol monoethyl ether (EGME) on nine soils. Analysis of the organic-matter content of the nine soils by 10 soil testing laboratories resulted in highly significant differences among laboratories.

Herbicide Phytotoxicity as Affected by Selected Properties of North Carolina Soils

Weed Science ◽  
1976 ◽  
Vol 24 (1) ◽  
pp. 120-126 ◽  
Author(s):  
G. W. Harrison ◽  
J. B. Weber ◽  
J. V. Baird
Keyword(s):  
North Carolina ◽  
Organic Matter ◽  
Water Solubility ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Volume Weight ◽  
Herbicide Activity ◽  
Highly Correlated ◽  
Physical And Chemical

Preemergence applications of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], chloramben (3-amino-2,5-dichlorobenzoic acid), fluometuron [1,1-dimethyl-3-(α,α,α-trifluro-m-tolyl)urea], propachlor (3-chloro-N-isopropylacetanilide), and trifluralin (α,α,α-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine) were compared in 10 North Carolina soils and the relationship of activity to soil physical and chemical properties appraised. Oats (Avena sativaL. ‘Carolee’) were used as the indicator plant in bioassays under greenhouse conditions. Fifteen soil properties were measured and correlated with herbicide I50(50% fresh weight inhibition) values. Organic matter was the soil variable most highly correlated with herbicide phytotoxicity. There was an inverse relationship between herbicide water solubility and inactivation by organic matter. Volume weight determinations and water holding capacity values (0.1 bar) provided relatively good estimates of soil organic matter contents, but were not as highly related to herbicide activity as organic matter content.

Adsorption of Ametryne and Diuron by Soils

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 470-474 ◽  
Author(s):  
L. C. Liu ◽  
H. Cibes-Viadé ◽  
F. K. S. Koo
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Puerto Rican ◽  
Cation Exchange Capacity ◽  
Equilibrium Solution ◽  
Soil Property ◽  
Organic Matter Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
Highly Correlated

The adsorption of 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine (ametryne) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) varied greatly among 34 Puerto Rican soils was studied using the agitated slurry technique. Adsorption was expressed as a distribution coefficient (Kd), which is the ratio of the amount of herbicide adsorbed to the amount in the equilibrium solution. In general, diuron was adsorbed to a greater degree than ametryne. Adsorption of ametryne was positively correlated with organic matter and silt content but negatively correlated with pH of the soil. The inclusion of soil pH in a multiple regression analysis contributed the highest increase in explanation for adsorption of ametryne. Adsorption of diuron was highly correlated with organic matter content and cation exchange capacity. A correlation was found between adsorption of diuron and content of magnesium, and soil texture. Cation exchange capacity was the only inclusion soil property which, in addition to organic matter, significantly contributed to the adsorption of diuron. Temperature appeared to have a greater effect on the adsorption of diuron than on the adsorption of ametryne. Conversely, the effect of pH on the adsorption of ametryne was significantly greater than that of diuron.

scholarly journals Diversity and spatial and temporal variation of benthic macroinvertebrates with respect to the trophic state of Lake Figueira in the South of Brazil

2013 ◽  
Vol 25 (4) ◽  
pp. 429-441 ◽  
Author(s):  
Fernanda Blauth de Lima ◽  
Alois Edward Schäfer ◽  
Rosane Maria Lanzer
Keyword(s):  
Organic Matter ◽  
Benthic Macroinvertebrates ◽  
Trophic State ◽  
Organic Matter Content ◽  
Matter Content ◽  
Spatial And Temporal Variation ◽  
Taxon Richness ◽  
Highly Correlated ◽  
South Of Brazil ◽  
Faunal Distribution

Benthic macroinvertebrates are widely used in evaluations of environmental impact and recommended in biomonitoring, but little used in Brazilian lentic environments. One of the main objectives has been to explain and predict the distribution of those species according to environmental characteristics. Thus, the study aims to characterize the predominant fauna of the Lake Figueira sediment and its relationship with organic matter and depth, analyzing seasonal variation in communities and aiming to select bioindicators of the trophic state. Sampling was carried out from January 2008 to January 2009, along the lagoon fetch, with an Ekmann-Birge dredge (area 225 cm²). Taxon richness was not significantly related with depth and organic matter content, but those variables were highly correlated (r = 0.962; r² = 0.926 and p < 0.001). The constant oxygenation of the whole water column allows the occurrence of organisms, independent of depth and organic matter content. Chironomidae was the most abundant taxon and from the frequency of occurrence, abundance and clustering analysis it was possible to select Larsia sp. , Goeldichironomus maculatus, Xenochironomus sp. , Aedokritus sp. Cladopelma forcipis, Cryptochironomus brasiliensis, Nilothauma sp.1 and Caladomyia sp. C, Tanytarsus sp. , Tanytarsus rhabdomantis and Chironomus gr. salinarius as potential indicators related with the spatiotemporal faunal distribution of Lake Figueira.

Sugarbeet (Beta vulgaris) Response to and Sorption Characteristics of Nicosulfuron and Primisulfuron

1995 ◽  
Vol 9 (3) ◽  
pp. 484-489 ◽  
Author(s):  
Karen M. Novosel ◽  
Karen A. Renner ◽  
James J. Kells ◽  
Andrew J. Chomas
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Yield Reduction ◽  
Sulfonylurea Herbicides ◽  
Soil Organic Matter Content ◽  
Highly Correlated ◽  
One Year ◽  
Sorption Characteristics

Nicosulfuron and primisulfuron are sulfonylurea herbicides that may persist in the soil and injure sensitive rotational crops such as sugarbeet. Studies were initiated to measure sugarbeet response one and two years after application of 70 and 140 g/ha of nicosulfuron and 40 and 80 g/ha of primisulfuron to corn. Nicosulfuron did not injure sugarbeet one or two years after application. In contrast, sugarbeet yield was reduced one year after application of 40 and 80 g/ha of primisulfuron. Injury was visible two years after application of 80 g/ha primisulfuron but this did not cause a yield reduction. In greenhouse studies, the concentration of nicosulfuron and primisulfuron that reduced sugarbeet growth by 50% were determined for six soils. Primisulfuron reduced sugarbeet growth more than nicosulfuron on four of six soils indicating greater potential for sugarbeet injury from primisulfuron. Sugarbeet response was highly correlated with soil organic matter content (R2= 0.88). The sorption coefficients, Kdvalues, for nicosulfuron were 0.30 to 2.58 and the Kdvalues for primisulfuron were 0.76 to 3.47. Primisulfuron Kdvalues were higher than those of nicosulfuron on four of five soils indicating stronger affinity of primisulfuron for soil sorptive sites. The Kdvalues for both herbicides indicate low overall sorption. The greater sugarbeet injury observed in the field from primisulfuron is not due to greater availability of primisulfuron compared to nicosulfuron.

scholarly journals Adsorption of Fluometuron, Prometryne, Sencor, and 2,4-D by Soils

1969 ◽  
Vol 57 (4) ◽  
pp. 286-293 ◽  
Author(s):  
L. C. Liu ◽  
H. R. Cibes-Viadé
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Adsorption Capacity ◽  
Cation Exchange Capacity ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content ◽  
The Mean ◽  
Highly Correlated

The adsorption capacity of Fluometuron, Prometryne, Sencor, and 2,4-D by 48 local soils was determined spectrophotometrically. The mean adsorptivities of the four herbicides by these soils were as follows: Prometryne 37.0 percent, Sencor 23.0 percent, Fluometuron 22.6 percent, and 2,4-D 12.4 percent. The results indicated that organic matter content was the factor most highly correlated with adsorption of these herbicides by the 48 soils. Cation exchange capacity was found to correlate significantly with adsorption of Fluometuron, Prometryne, and Sencor. Such was not the case with 2,4-D. Correlation between clay content and adsorption of Fluometuron and Sencor was statistically significant. In contrast, no significant correlation was noted between clay content and adsorption of Prometryne and 2,4-D.

Adsorption, Mobility, and Efficacy of Metribuzin as Influenced by Soil Properties

Weed Science ◽  
1985 ◽  
Vol 33 (6) ◽  
pp. 868-873 ◽  
Author(s):  
C. John Peter ◽  
Jerome B. Weber
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Surface Area ◽  
Water Solubility ◽  
Organic Matter Content ◽  
Matter Content ◽  
Water Soluble ◽  
Soil Parameters ◽  
Glycol Monoethyl Ether ◽  
Highly Correlated

The effect of various soil parameters on metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] efficacy was studied on seven soils and metribuzin adsorption was investigated in nine soils. Soil organic-matter and clay contents were correlated with metribuzin activity. Specific surface area, as measured by ethylene glycol monoethyl ether (EGME) was highly correlated with metribuzin activity. Soil organic-matter content and EGME surface area measurements were also highly correlated with metribuzin adsorption in soils. Since metribuzin is highly water soluble (water solubility greater than 1000 ppm), it was probably adsorbed at the hydrophilic sites on the soil surfaces that were measured by EGME. Metribuzin was much more mobile than atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine] in a leaching study.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

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