Interactions of Buthidazole with Clay Minerals and Soils

Weed Science ◽  
1981 ◽  
Vol 29 (6) ◽  
pp. 667-671
Author(s):  
Song-Wu Li ◽  
Max M. Mortland

The newly developed herbicide buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadizol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone} was studied with respect to its interaction with soils and homoionic clay minerals and its response to irradiation with ultraviolet light. Results showed that it could enter the interlamellar spaces of swelling clays such as smectite. Isothermic adsorption studies indicated that Cu+2-smectite adsorbed more buthidazole than Cu+2-kaolinite. The Cu+2-clay adsorption isotherm fitted the Langmuir model. The effect of exchangeable cations on adsorption was not significant in soils of high organic matter content. Bioassay studies indicated that buthidazole's phytotoxicity was not decreased in either clays or in organic soils. Infrared spectroscopic studies showed the coordination of buthidazole with Cu+2through C=O Cu interaction with buthidazole resulted in a ligand-to-metal ratio to 1:1. Protonation of buthidazole occurred in Al+3-and H+-smectite. The herbicide was labile to UV-light irradiation at 254 nm but not at 366 nm. The photoconversion indicated a first-order reaction. The photolytic product(s) included the –N=C=O structure. Copper(II) ions, which form complexes, retarded photolysis of buthidazole in UV-light, but the Ca+2ion, which is unable to form complexes, did not.

2019 ◽  
Vol 34 (3) ◽  
pp. 362-370
Author(s):  
Jose V. Fernandez ◽  
D. Calvin Odero ◽  
Gregory E. MacDonald ◽  
Jason A. Ferrell ◽  
Brent A. Sellers ◽  
...  

AbstractDissipation of S-metolachlor, a soil-applied herbicide, on organic and mineral soils used for sugarcane production in Florida was evaluated using field studies in 2013 to 2016. S-metolachlor was applied PRE at 2,270 g ha−1 on organic and mineral soils with 75% and 1.6% organic matter, respectively. The rate of dissipation of S-metolachlor was rapid on mineral soils compared with organic soils. Dissipation of S-metolachlor on organic soils followed a negative linear trend resulting in half-lives (DT50) ranging from 50 to 126 d. S-metolachlor loss on organic soils was more rapid under high soil-moisture conditions than in corresponding low soil-moisture conditions. On mineral soils, dissipation of S-metolachlor followed an exponential decline. The DT50 of S-metolachlor on mineral soils ranged from 12 to 24 d. The short persistence of S-metolachlor on mineral soils was likely attributed to low organic matter content with limited adsorptive capability. The results indicate that organic matter content and soil moisture are important for persistence of S-metolachlor on organic and mineral soils used for sugarcane production in Florida.


2006 ◽  
Vol 63 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Marcos Gervasio Pereira ◽  
Gustavo Souza Valladares ◽  
Lúcia Helena Cunha dos Anjos ◽  
Vinícius de Melo Benites ◽  
Ademar Espíndula Jr. ◽  
...  

Soil taxonomy systems distinguish mineral soils from organic soils based on the amount of soil organic carbon. Procedures adopted in soil surveys for organic carbon measurement are therefore of major importance to classify the soils, and to correlate their properties with data from other studies. To evaluate different methods for measuring organic carbon and organic matter content in Histosols and soils with histic horizons, from different regions of Brazil, 53 soil samples were comparatively analyzed by the methods of Walkley & Black (modified), Embrapa, Yeomans & Bremner, modified Yeomans & Bremner, muffle furnace, and CHN. The modified Walkley & Black (C-W & B md) and the combustion of organic matter in the muffle furnace (OM-Muffle) were the most suitable for the samples with high organic carbon content. Based on regression analysis data, the OM-muffle may be estimated from C-W & B md by applying a factor that ranges from 2.00 to 2.19 with 95% of probability. The factor 2.10, the average value, is suggested to convert results obtained by these methods.


Author(s):  
Dace Kļaviņa ◽  
Anita Osvalde

Abstract The main aim of the study was to evaluate the soil chemical characteristics of Cypripedium calceolus sites in Latvia for understanding of the species ecology, and its conservation problems and possibilities. Soil for 27 C. calceolus sites in Latvia was analysed during 2007-2015. The concentration of plant available essential nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B), soil pH, electrical conductivity and concentration of organic matter were determined. Nutrient concentration of C. calceolus leaf samples from six sites were determined. The results demonstrated high heterogeneity in soil chemical composition with high variation for Ca, Mg, and Mn. The results suggest some relationship between soil organic matter content and size of the orchid population. Soil pH and Ca concentration did not affect the size and vitality of C. calceolus populations in Latvia. There was no significant correlation between nutrient concentration in soil and C. calceolus leaves suggesting strong impact of other soil-related factors in determining the availability of nutrients. In general, the levels of N, P, K, Ca, Mg, Fe, Mn, and Zn concentrations in C. calceolus leaves were adequate or slightly decreased for successful orchid growth. The study showed deficiency of S, Cu, and B in the vast majority of leaf samples. C. calceolus sites in Latvia occur mainly on organic soils or mineral soils with high content of organic matter. There was a weak positive correlation (r = 0.21) observed only between total number of ramets of C. calceolus in site and Ca concentration in the soil, suggesting that soil properties are not a main factor affecting species abundance in the site.


1967 ◽  
Vol 47 (2) ◽  
pp. 83-88 ◽  
Author(s):  
S. K. Rana ◽  
G. J. Ouellette

Studies on thirty mineral soil series and five organic soils from the broad cultivated areas of Quebec indicated that total cobalt, extracted with 70% perchloric acid digestion, ranged from 1.1 to 21.6 ppm and 2.5% acetic acid-extractable cobalt from 0.3 to 0.83 ppm. Extractable cobalt in the surface soils was significantly correlated with total cobalt, which in turn was highly dependent on the clay content of the soil. The soil pH or the organic matter content did not seem to have any influence on the cobalt content in the cultivated soils. Light-textured and podzolized soils are likely to be low m cobalt, while soils with richer clay content are higher. Organic soils, in general, were found to be lower in cobalt content than mineral soils. Nineteen out of the thirty mineral soils studied and all the organic soils contained less than 0.25 ppm of extractable cobalt and may be considered as critical or deficient because forage grown on such soils is likely to cause cobalt deficiency in livestock.


Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Andrzej Lachacz ◽  
Monika Nitkiewicz ◽  
Barbara Kalisz

AbstractThe objective of this study was to estimate the water repellency of post-boggy soils in north-eastern Poland. Potential water repellency was determined based on the water drop penetration time (WDPT) test and the molarity of an ethanol droplet (MED) test. A total of 276 soil samples with a varied organic carbon (OC) content, ranging from trace amounts in sandy subsoils to 44.4% in organic soils, were analyzed. The investigated material represents peat-muck soils (Eutri-Sapric Histsols) and muck-like soils (Arenic Gleysols, Areni-Humic Gleysols, Gleyic Arenosols). The mineral matter of the analyzed soils comprised loose sand. The obtained results indicate that peat soil formations are marked by higher potential water repellency than muck soil formations. The highest WDPT values (16 390 s) were reported in respect of an alder peat sample with 41.9% OC content, collected at a depth of 55–60 cm. In the group of muck soils, a sample with 36.7% OC content, collected at a depth of 15–20 cm, was marked by the highest water repellency (WDPT 10 492 s). The water repellency of the studied soils is dependent on organic matter content, and it is manifested only when organic matter content is higher than 20%. Soils with OC content of up to 12% show low water repellency or are hydrophilic. Organic soil formations (>12% OC) are characterized by a varied degree of water repellency, but WDPT values in excess of 2000 s are reported only in respect of soils containing more than 35% OC. A significant positive correlation between the content of organic matter, organic carbon, total nitrogen and water repellency was observed in the entire studied population (n = 276). A significant positive correlation was also found between WDPT values and the C:N ratio, while a significant negative correlation was reported in respect of $$ pH_{H_2 O} $$.


2009 ◽  
Vol 33 (4) ◽  
pp. 1071-1076 ◽  
Author(s):  
Daniel Vidal Perez ◽  
Lúcia Helena Cunha dos Anjos ◽  
Adierson Gilvani Ebeling ◽  
Marcos Gervasio Pereira

Exchangeable Al has been used as a criterion for the calculation of lime requirement in several Brazilian States. However, the laboratory method with extraction by a 1 mol L-1 KCl solution followed by indirect alkaline titration is not accurate for some Brazilian soils, mainly in the case of soils with high organic matter content. The objective of this study was therefore to evaluate the stoichiometry of H+/Al3+ in KCl soil extracts. The results suggested that organically complexed Al is the main contributor to exchangeable acidity in soils enriched with organic matter. Liming recommendations for organic soils based exclusively on exchangeable Al determined by the NaOH titration method should therefore be revised.


2018 ◽  
Vol 196 ◽  
pp. 03015
Author(s):  
Dmitry Chunyuk ◽  
Olga Kopteva

In the proposed article the author examines issues determining physical and mechanical soils with organic matter content. Conditional definitions of organic soils depending on the value of the relative organic content matter are determined. The biogenic soils are examined using three groups - peat, blocked soils and sapropels. Depending on the relative content of organic substances, the author compares various peat types. The division of the soils with organic content is presented. A definition of sapropels is presented. The problem of complexity of determination of the amount of organic substances by calcination of samples is described. The current methods used to determine the amount of organic substances currently in Russia isexamined. The paper reviews physical and mechanical properties of organic soils. The on-site test-plate data is compared with laboratory test data. The problems of sapropel tests are described. The results of experimental studies, conducted at a construction site in the new suburban district of Moscow are shown.


2018 ◽  
Vol 12 (1) ◽  
pp. 34-39
Author(s):  
Baghdad Science Journal

The present research included sampling and analysis of 41 soil samples , the samples cover various areas of Nasiriyah city (industrial,commercial,residential and agricultural ) to estimate pollution levels of lead element and determine the correlation between lead concentration and natural factors in soil which represent sedimentary organic matter content, granular gradient, clay minerals and non-clay minerals . The results of the current study showed that the average concentration of lead in the soil samples was 61.12 ppm , it was noticed an increase in the concentration of lead in environmental components in the area of this study especially in residential , industrial and commercial location and the impact of natural factors of the soil was limited and the main factors of pollution is resulting from human activities


2021 ◽  
Author(s):  
Robert Mickler

Abstract Background: One of the scientific challenges of understanding climate change has been determining the important drivers and metrics ofglobal carbon (C) emissions and C cycling in tropical, subtropical, boreal, subarctic, and temperate peatlands. Peatlands account for 3% of global land cover, yet contain a major reservoir of 550 gigatons (Gt) of soil C, and serve as C sinks for 0.37 Gt of carbon dioxide (CO2) a year. In the United States, temperate peatlands areestimated to store 455 petagrams of C (PgC).There has been increasing interest in the role of wildfires in C cycling and altering peatlands from C sinks to major C sources. We estimated above- andbelow-ground C emissions from the Pains Bay Fire, a long-duration wildfire (112 days; 18,329 ha)that burned a coastal peatlandin eastern North Carolina, USA. Results: Soil C emissions were estimated from pre- and post-burn Light Detectionand Ranging (LIDAR) soil elevation data,soils series and C content mapping, remotely sensed soilburn severity, and post-burn field surveys of soil elevation.Total above-ground C emissions from the fire were 289,579 tC and 214 t C ha-1for the 10 vegetation communitieswithin the burn area perimeter. Above-ground sources of C emissions were comprised of litter (69,656 t C), shrub (168,983 t C), and foliage (50,940 t C).Total mean below-ground C emissions were 5,237,521 t C, and ranged from 2,630,529 – 8,287,900 t C,depending on organic matter content of different soil horizonswithin each of the 7 soil series. The mean below-ground C emissions within the burn area were 1,595.6 t C ha-1 and rangedfrom 629.3 – 2,511.3 t C ha-1.Conclusions: In contrast to undisturbed temperate peatlands, human induced disturbances of thenatural elevation gradient of the peatland has resulted in increased heterogeneity of floristic variation and assemblages that are a product of the spatial and temporal patterns of the water table level and the surface wetness across peatlands. Human induced changes in surface hydrology and land use influenced the fuel characteristics of natural vegetation and associated soils, thus influencing wildfire risk, behavior, and the resulting C emissions.


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