scholarly journals Sorption, Desorption and Mobility of Microencapsulated Chlorpyrifos in Two Typical Soils

Author(s):  
Liezhong Chen ◽  
Yanli Li ◽  
Ting Wang ◽  
Yunlong Yu

Abstract The sorption, desorption, and mobility of microencapsulated chlorpyrifos (CPF-MC) in two typical soils, namely, silt loam and sandy, were investigated in this study. Sorption/desorption experiments were carried out by using the batch equilibration method. Results showed that the sorption isotherms of CPF-MC and emulsifiable concentrate of chlorpyrifos (CPF-EC) in silt loamy soil were similar. However, a considerable difference was observed in the sorption isotherms of two chlorpyrifos (CPF) formulations in sandy soil. The amounts of CPF desorbed from two soils in four desorption steps decreased sequentially in CPF-EC treatments, while the desorbed amounts remained stable in CPF-MC treatments. Hence, the sorption/desorption processes of CPF-EC were mainly controlled by soil affinity to CPF. However, these processes of CPF-MC were affected by the release rate of CPF from capsules. The mobility of two CPF formulations in soil were estimated in vertical columns packed with soils. Results showed that there was leaching of CPF-EC in silt loam column, whereas CPF-MC was not vertically mobile in silt loam column under the same leaching conditions. However, in column with sandy soil, the percentage of CPF-MC leaching from the column was 86.54%, which was higher than the 73.75% that leached from the column in the treatment with CPF-EC.

Weed Science ◽  
1982 ◽  
Vol 30 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Victor Raboy ◽  
Herbert J. Hopen

The persistence and effectiveness in pumpkin [Cucurbita moschata(Puch.) Poir.] weed control of several starch xanthide (SX) and commercial formulations of the ammonium (NH3) salt and methyl (CH3) ester of chloramben (3-amino-2,5-dichlorobenzoic acid) were studied in the laboratory and field. The soluble concentrate (SC) of chloramben NH3salt and the emulsifiable concentrate (EC) of chloramben CH3ester controlled weeds throughout the growing season on a silt loam soil. SC chloramben NH3salt was not effective, and EC chloramben CH3ester was inconsistent in weed control on sandy soil. Manipulation of the SX formulation produced products with slow, uniform release rates. The release rates (crosslinking reagent in parenthesis) rank as follows, from fastest to slowest: SX(Ca2+) CH3ester = SX(H2O2) acid > SX(H2O2) CH3ester > SX(Fe3+) acid > SX(Fe3+) CH3ester. In trials on silt loam and sand, SX formulations did not control weeds better than EC chloramben CH3ester.


2021 ◽  
Author(s):  
CI Chemistry International

A regression analysis model was developed to examine the reliability and the acceptability of the sun-dried and room-dried Azadirachta indica leaves for the remediation crude oil contaminated soil in Niger Deltal, Nigeria. An experimental approach was used to monitor the concentration of the total petroleum hydrocarbon (TPH) degradation that was enhanced in the presence of the microbes in the reactor. A regression analysis was performed to evaluate the reaction behavior microbes in reactor for the remediation of the TPH in the presence of sun-dried and room-dried A. indica leaves in sandy and loamy soils contaminated with 100 ml of crude oil. The physicochemical properties of control loamy soil was as; pH (6.75), electric conductivity (10.36 μS/cm), total oxygen (2.99%), total Nitrogen (0.091%), potassium (36.82942%), phosphorus (15.36%) and total bacteria (2.15×102 cfu/g). Whereas, these values were as pH (6.82), electric conductivity (21.48 μS/cm), total oxygen content (1.18%), total nitrogen (0.036%), potassium (24.03681%), phosphorus (5.18%) and total bacteria count (1.86×102 cfu/g) for sandy soil. The inoculant was prepared by blending sun-dried and room-dried A. indica leaves. The blended A. indica leaves in 50 to 100 g range were applied on the polluted soils for 35 days and significant reduction in contaminating agents was observed. The highest remediation was observed in soils treated with 100 g room dried A. indica leaves. A 96% remediation recorded in sandy soil treated with 100 g room dried A. indica leaves as TPH depleted from 35818.69 mg/kg to 1349.109 mg/kg and 92% reduction was observed in loamy soil treated with 100 g dried A. indica leaves and TPH depleted from 48508.92 mg/kg to 3977.739 mg/kg. The regression model developed was successfully employed to predict TPH remediation behavior, which can be applied to monitor remediation of contaminated soil.


Author(s):  
А.С. Дурова ◽  
А.В. Жигунов

Улучшение агрохимических, физико-химических и биологических показателей почвы в результате внесения биоугля в качестве мелиоранта доказано множеством исследований. Наиболее эффективным при выращивании сельскохозяйственных культур оказалось применение мелиоранта в дозах от 1 до 30 т/га биоугля. Однако вопрос о влияния биоугля на рост сеянцев хвойных пород в посевных отделениях лесных питомников в научной литературе затронут не был. Целью исследования была оценка влияния различных доз биоугля на агрохимические параметры почв лесных питомников различного гранулометрического состава и на рост сеянцев ели обыкновенной Picea abies (L.). Фракции биоугля мелкого помола (диаметр частиц менее 5 мм) вносились в метровые отрезки пяти строчных посевных лент в дозах 5 и 25 т/га. В контрольных вариантах опыта биоуголь не вносился. Для посева использовали сухие семена хвойных пород, подготовленные к посеву по стандартным методикам. Проведение агротехнических приемов по выращиванию сеянцев проводилось по стандартным технологическим картам. Эксперимент проводился в пятикратной повторности. Изучался рост и развитие сеянцев ели европейской в течение трех вегетационных сезонов, а также показатели плодородия почв в посевных отделениях лесных питомников. На опытных делянках в конце каждого вегетационного сезона определялась высота сеянца и диаметр корневой шейки. Для определения массы было отобрано 30 модельных сеянцев. Масса определялась после высушивания до постоянного веса при температуре 80 С. Оценку параметров почвенного плодородия проводили по показателям содержания углерода органического вещества, кислотности, а также определялось содержание доступных форм азота, фосфора и калия. Выполнение агрохимических анализов производилось по стандартным методикам. Отбор проб почвы производился методом конверта в соответствии с ГОСТ 174.3.01–83. Для оценки достоверности влияния применяемых доз биоугля на рост сеянцев использовался однофакторный дисперсионный анализ. Внесение биоугля в почву посевного отделения питомников в дозе 5 и 25 т/га повлияло на изменение агрохимических показателей как песчаной, так и супесчаной почвы. В более плодородной супесчаной почве биоуголь положительно воздействовал на агрохимические показатели, что привело к улучшению показателей роста ели в первый вегетационный период. Однако воздействие биоугля на агрохимические показатели супесчаной почвы с течением времени постепенно снижалось. При внесении биоугля в дозе 5 т/га быстро срабатывается углерод, снижается содержание азота, что приводит к нивелированию показателей роста сеянцев по высоте уже после второго вегетационного сезона. Однако увеличение диаметра корневой шейки и массы сеянца достоверно по отношению к контролю при внесении и 5, и 25 т/га биоугля после трех лет выращивания. На песчаной почве эффект воздействия биоугля на почву более растянут во времени. К концу 3-го года положительные изменения агрохимических параметров почвы все еще продолжаются при внесении и 5, и 25 т/га биоугля. Однако вследствие более низких агрохимических показателей песчаной почвы рост сеянцев в этих условиях остается низким, и сеянцы за три года выращивания не достигают стандартных параметров даже при внесении мелиоранта. Improvement of agrochemical, physical, chemical and biological properties of soil as a result of biochar application as an ameliorant has been proved in numerous studies. Application of ameliorant in biochar doses ranging from 1 to 30 tons per ha has proved to be most effective in growing crops. However, biochar effects on the growth of coniferous seedlings in the sowing section of forest nurseries have not been considered in the literature. The aim of the research was to study the effects of different biochar doses on agrochemical parameters of soils in forest nurseries with different granulometric soil composition and on the growth of spruce seedlings (Picea abies (L.)). Biochar fine-ground fractions (5 mm in diameter) were introduced into one-meter length lines of five-row sowing tapes in doses of 5 and 25 t/ha. In the control variants of the experiment, biochar was not introduced. For seeding, dry conifer seeds were used, which were prepared for sowing by standard methods. Agrotechnical methods for growing seedlings were carried out according to standard technological maps. The experiment had five replicates. The growth and development of European spruce seedlings as well as soil fertility parameters were studied during three growing seasons in the sowing sections of forest nurseries. At the experimental plots, the height of the seedlings and the diameter of their root collars were determined at the end of each growing season. 30 model seedlings were selected to determine the mass of a seedling, which was done after the seedlings were dried to a constant weight at a temperature of 80 C. The soil fertility parameters were evaluated based on the carbon content of organic matter and acidity; in addition, the contents of available forms of nitrogen, phosphorus and potassium were determined. The agrochemical analyses were performed using standard methods and procedures. Soil sampling was carried out using the envelope method in accordance with GOST 174.3.01–83. The validity of the applied biochar doses on the growth of seedlings was assessed with the single-factor analysis of variance. The introduction of biochar to the soil of the nursery sowing section in doses of 5 and 25 t/ha influenced the agrochemical parameters of both sandy and sandy loamy soil. In more fertile sandy loam soils, biochar positively influenced agrochemical parameters of the soil, which resulted in higher growth rates of spruce in the first growing season. However, the biochar effects on the agrochemical parameters of sandy loamy soil gradually decreased with time. When biochar was applied in a dose of 5 t/ha, carbon and nitrogen contents decreased significantly, which led to leveling of height growth of seedlings after the second growing season. However, increase in the seedling root collar diameter and weight was significant with respect to the control for both doses of biochar, 5 and 25 t/ha, after three years of cultivation. On sandy soil, the biochar effects on soil were more extended in time. By the end of 3 years, positive changes in the agrochemical parameters of the soil were still going on for both doses, 5 and 25 t/ha. However, due to lower agrochemical parameters of sandy soil, the growth of seedlings in these conditions remained low and the seedlings did not reach the standard parameters after three years of cultivation, even with the introduction of ameliorant.


2020 ◽  
Vol 66 (2) ◽  
pp. 45-55
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský

AbstractScientific studies show that the efficiency of biochar can be improved by its combination with other fertilisers. For this reason, fertiliser manufacturers are working to create products that combine biochar with other soil fertility enhancers suitable for different soil-climatic conditions. In this study, two types of biochar substrates (1. biochar blended with farmyard manure, and 2. biochar blended with farmyard manure as well as with digestate) at rates of 10 and 20 t/ha were applied alone or in combination with other manure and mineral fertilisers. These were added to Arenosol (sandy soil, Dolná Streda, Slovakia) and Chernozem (loamy soil, Veľké Úľany, Slovakia) to evaluate the soil physical properties to test the potential of these amendments for soil amelioration in texturally different soils. The results showed that the application of biochar substrates alone increased soil moisture, the volume of capillary pores, and decreased aeration and volume of non-capillary pores. The application of biochar substrates with mineral fertilisers increased aeration, content of water-stable macro-aggregates (WSAma), total porosity, and decreased soil moisture and the content of water-stable micro-aggregates (WSAmi) in sandy soil. In loamy soil, when compared to unfertilised control, the biochar treatments increased content of WSAma, content of dry-sieved macro-aggregates, and decreased content of WSAmi and content of dry-sieved micro-aggregates. The combination of biochar substrates together with manure had no effect on changes in the physical properties of loamy soil.


Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 262-266 ◽  
Author(s):  
Sharon A. Clay ◽  
William C. Koskinen

Adsorption and desorption isotherms for atrazine and two metabolites, hydroxyatrazine (HA) andS-glutathione atrazine (GSHA), were determined by batch equilibration on Plano and Waukegan silt loam soils at two soil pH levels (Plano, 6.1 and 4.5; Waukegan, 6.1 and 4.0). Freundlich adsorption isotherms were not affected by soil type except for GSHA at pH 4.0 to 4.5. When averaged over both soils, the order of adsorption at pH 6.1 was atrazine (Kf= 3.7) < GSHA (Kf= 7.3) << HA (Kf= 25) and at pH 4.0–4.5 was atrazine (Kf= 6.1) << HA (Kf= 58) ≤ GSHA (Kf: Plano = 35; Waukegan = 78). The average slope of the adsorption isotherms (1/nads) was 0.81. The slopes of all desorption isotherms (1/ndes) were less than their respective 1/nads, indicating hysteresis. Atrazine desorbed into soil solution (1/ndes> 0.0). With the exception of GSHA which desorbed from the pH 6.1 Plano silt loam (1/ndes= 0.15), desorption of HA and GSHA from other treatments was negligible (1/ndes= 0.0). Consequently, leaching of HA and GSHA in these and similar soils is not likely, due to high adsorption and low desorption.


Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 165 ◽  
Author(s):  
Sara de Jesus Duarte ◽  
Bruno Glaser ◽  
Carlos Pellegrino Cerri

The application of biochar is promising for improving the physical, chemical and hydrological properties of soil. However, there are few studies regarding the influence of biochar particle size. This study was conducted to evaluate the effect of biochar size on the physical, chemical and hydrological properties in sandy and loamy tropical soils. For this purpose, an incubation experiment was conducted in the laboratory with eight treatments (control (only soil), two soils (loamy and sandy soil), and three biochar sizes (<0.15 mm; 0.15–2 mm and >2 mm)). Analyses of water content, bulk density, total porosity, pore size distribution, total carbon (TC) and total N (TN) were performed after 1 year of soil–biochar-interactions in the laboratory. The smaller particle size <0.15 mm increased water retention in both soils, particularly in the loamy soil. Bulk density slightly decreased, especially in the loamy soil when biochar > 2 mm and in the sandy soil with the addition of 0.15–2 mm biochar. Porosity increased in both soils with the addition of biochar in the range of 0.15–2 mm. Smaller biochar particles shifted pore size distribution to increased macro and mesoporosity in both soils. Total carbon content increased mainly in sandy soil compared to control treatment; the highest carbon amount was obtained in the biochar size 0.15–2 mm in loamy soil and <0.15 mm in sandy soil, while the TN content and C:N ratio increased slightly with a reduction of the biochar particle size in both soils. These results demonstrate that biochar particle size is crucial for water retention, water availability, pore size distribution, and C sequestration.


2016 ◽  
Vol 96 (5) ◽  
pp. 887-894 ◽  
Author(s):  
A. Moussavi ◽  
S.Z.H. Cici ◽  
C. Loucks ◽  
R.C. Van Acker

Taraxacum Kok-saghyz (L.E. Rodin) (TKS) is a natural source of rubber. There is a rising interest in TKS establishment as a new crop in Ontario. Trials were conducted at Simcoe and Guelph, Ontario between 2013 and 2014 to explore the possibility of establishing TKS plants from seed in fields in Ontario. The effects of seeding depth, watering regimes, polymer, and covering mulch on the recruitment of TKS were explored. It was found that TKS displays very low field recruitment levels regardless of treatment. KNO3 did not have any significant effect on TKS seed germination. Seedling emergence was greatest when seeds were placed on the soil surface and decreased with increasing seeding depth. Two years of field experiments highlighted that TKS seedlings recruit better in moderate conditions when the temperature is optimum for TKS germination (warm but not hot, <25 °C). TKS seedlings recruited better at Simcoe (with a sandy soil type) than at Guelph (with a loamy soil type). Overall, however, field recruitment from seed was low (15% at best) and these results suggest that establishing TKS from seed in Ontario fields remains a challenge.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Vladimír Šimanský ◽  
Elena Aydın ◽  
Ján Horák

Understanding nutrient management is essential to ensure healthy and adequate food production, especially in the context of biochar applied to soil with different soil textures. Additionally, farmers are beginning to understand the importance of nutrient management and there are still several knowledge gaps in this area. Several studies on biochar showed its positive effects, especially in sandy and nutrient-poor soils. There is still a lack of information on the impact of biochar on nutrient regimes in texturally different soils with sufficient nutrient supply and favorable soil chemistry. This study investigates the effect of two biochar substrates (a) biochar blended with farmyard manure (BS1), and (b) biochar blended with farmyard manure and digestate (BS2) applied at rates of 10 and 20 t ha−1 alone or in combination with fertilization on the changes in sorption capacity and nutrient regime of two texturally different soils: (a) sandy Arenosol, and (b) loamy Chernozem, (both in western Slovakia) which have a favorable nutrient content. The results showed that in sandy soil, the BS2 at rate of 20 t ha−1 increased the sum of basic cations (by +112%) and CEC (by +93%) compared to the control. In sandy soil, the content of total P increased by +35 and +16% in BS1 20 t ha–1 and BS2 20 t ha−1, respectively, when compared to the unfertilized control. The content of total P increased by +18% in BS1 20 t ha−1 after fertilization compared to the fertilized control. In loamy soil, the content of total P increased significantly by +53 and +14% in unfertilized treatment BS2 20 t ha−1 and fertilized treatment with BS1 at 20 t ha−1 compared to the respective controls. Available Ca increased in sandy soil by +50 and +53% in fertilized treatments with BS2 at 20 t ha−1 and BS1 at 20 t ha−1, respectively, when compared to fertilized control. In loamy soil, available Mg increased by +13% in fertilized treatment with BS1 applied at 20 t ha−1. In conclusion, BS application at a dose of 20 t ha−1 had a stronger positive effect on soil sorption parameters in sandy soil than the application dose of 10 t ha−1. The same BS application rate significantly increased total P in both soils.


2021 ◽  
Vol 12 (1) ◽  
pp. 341
Author(s):  
Chantal M. J. Hendriks ◽  
Vaibhav Shrivastava ◽  
Ivona Sigurnjak ◽  
Jan Peter Lesschen ◽  
Erik Meers ◽  
...  

The refinement level of bio-based fertilisers (BBFs) can influence environmental and agronomic performance. This study analyses the environmental and agronomic effect of different BBFs on potato growing in sandy soil. A less refined product (liquid fraction of digestate (LFD)), two refined products (ammonium sulphate (AS) and potassium concentrate (KC)), and mineral fertilizer (MF) are compared by conducting: (i) a nitrogen (N) incubation experiment where the N release rate of the BBFs is determined, (ii) a greenhouse gas emission experiment where N2O, CO2, and CH4 emissions after BBF application are measured, (iii) a pot experiment where the nutrient fertiliser replacement value (NFRV) of the BBF is calculated, and (iv) a full-scale field trial where the potato quality and quantity and the remaining N residues in the soil after harvest are assessed. The N release rate and the NFRV of AS (142 ± 19% and 1.13, respectively) was higher compared with the LFD (113 ± 24% and 1.04) and MF (105 ± 16% and 1.00). Lowest N2O emissions were observed after the application of the less refined product (0.02 ± 0.01 per 100 g N applied) and highest for MF urea (0.11 ± 0.02 per 100 g N applied). In the full-scale field trial, no significant difference in potato yield was observed in the plots that received manure in combination with BBF or MF. This study showed that all three BBFs can safely be used in potato growing on sandy soils. However, the adoption of BBFs can be stimulated by (i) solving the practical issues that occurred during the application of LFD, (ii) making sure BBFs are on the list of RENURE materials so they can legally replace mineral fertiliser, and (iii) reducing the surplus of slurry manure to stimulate the use and fair pricing of BBF products.


1993 ◽  
Vol 7 (4) ◽  
pp. 894-899 ◽  
Author(s):  
Stanley F. Gorski

Metolachlor, applied to the surface of leaching columns as dicalcium phosphate tablets, was recovered over a period of 25 d compared with 2 and 3 d for emulsifiable concentrate and granular formulations, respectively. In similar studies, approximately 27% of napropamide was recovered from tablets during the same period. Adding an adjuvant to the napropamide tablet mixture increased the recovery rate to 55%. Tablet hardness and size had little effect on the release rate of napropamide. Tablets containing 4% ai napropamide released greater amounts of herbicide at a single collection period than did tablets containing 1% ai. Adding an adjuvant to the napropamide tablet mixture significantly improved Italian ryegrass control in the area adjacent to herbicide placement.


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