scholarly journals Dissolution of Ag Nanoparticles in Agricultural Soils and Effects on Soil Exoenzyme Activities

Environments ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 22
Author(s):  
Nuno C. Cruz ◽  
Márcia Farto ◽  
Clarisse Mourinha ◽  
Daniela Tavares ◽  
Armando C. Duarte ◽  
...  
Keyword(s):  
Organic Matter ◽  
Agricultural Soils ◽  
Inhibitory Effect ◽  
Low Ph ◽  
Environmental Risks ◽  
Downward Mobility ◽  
Acidic Soils ◽  
Soil Enzymatic Activity ◽  
Soil Extractions ◽  
Chemical Availability

To assess environmental risks related to the mobility and toxicity of AgNPs, the chemical availability of AgNPs and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) in three agricultural soils was quantified in a pot experiment. Porewater collection and soil extractions with 0.01 M CaCl2, 0.4 M Glycine (pH 1.5) and 0.05 M NH4-EDTA were performed. The effect on soil exoenzyme activities was also assessed. Porewater concentration was low (<0.4% and <0.04% of dosed Ag, for AgNPs and PVP-AgNPs, respectively) and only detected in acidic soils (pH 4.4 and 4.9). The PVP-coating reduced the downward mobility of AgNPs in soil and possibly also their dissolution rate (and subsequent release of dissolved Ag+ ions into porewater). The effect of variation in organic matter on soil enzymatic activity was larger than that of AgNPs, as no significant additional inhibitory effect from Ag could be observed. Only at low pH and in the presence of complexing ligands that form very stable Ag complexes (0.4 M Glycine extraction at pH 1.5) up to 58% of the Ag added to soil was released (independently of PVP coating). An extraction with glycine is proposed as a useful indicator of potentially available Ag in soils.

scholarly journals Soil organic matter and ammonium affect potassium retention in soil microaggregates under long--term fertilization

2021 ◽  
Author(s):  
Mingjun Chen ◽  
Xiaoqin Chen ◽  
Shahbaz Muhammad ◽  
Tida Ge ◽  
Huoyan Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Agricultural Soils ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Npk Fertilizers ◽  
Straw Return ◽  
Potassium Retention ◽  
Positive Effect

The adsorption and fixation of potassium in agricultural soils are important as they influence K availability for crops. Soil organic matter (SOM) and ammonium (NH4+) exist in soils and play indispensable roles in soil fertility and crop yield; however, the effects of SOM and NH4+ on K retention in soil aggregate remains unclear. This study aimed to evaluate the effects of SOM and NH4+ on K adsorption and fixation in soil microaggregates (<0.25 mm). Soil microaggregates were extracted from three long-term fertilization treatments under rice-wheat rotations: no fertilizer (CK), fertilized with inorganic NPK (NPK), and inorganic NPK fertilizers combined with straw return (NPKS). Long-term fertilization, particularly the application of inorganic NPK combined with straw return, significantly improved the SOM content in microaggregates. Both NPK and NPKS treatments increased K adsorption but decreased K fixation, and SOM oxidation of microaggregates reduced K adsorption but increased K fixation in all treatments, indicating the positive and inhibitory effects of SOM on K adsorption and fixation, respectively. NH4+ significantly inhibited K adsorption and fixation, and this inhibitory effect was more significant in microaggregates with a higher SOM content. Although NH4+ reduced the positive effect of SOM on K adsorption, it enhanced the inhibitory effect of SOM on K fixation. Conclusionally, long-term fertilization increases K adsorption but reduces K fixation by improving SOM content, where NH4+ enhances SOM inhibited K retention in soil microaggregates, which is considered to improve K availability in soils amended with K fertilizers. Keywords: soil organic matter, NH4+, K, adsorption, fixation

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

scholarly journals Describing Phosphorus Sorption Processes on Volcanic Soil in the Presence of Copper or Silver Engineered Nanoparticles

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 373
Author(s):  
Jonathan Suazo-Hernández ◽  
Erwin Klumpp ◽  
Nicolás Arancibia-Miranda ◽  
Patricia Poblete-Grant ◽  
Alejandra Jara ◽  
...  
Keyword(s):  
Organic Matter ◽  
Crop Production ◽  
Agricultural Soils ◽  
Ph Value ◽  
Consumer Products ◽  
Soil Samples ◽  
Engineered Nanoparticles ◽  
P Availability ◽  
Agricultural Crop ◽  
Phosphorus Sorption

Engineered nanoparticles (ENPs) present in consumer products are being released into the agricultural systems. There is little information about the direct effect of ENPs on phosphorus (P) availability, which is an essential nutrient for crop growthnaturally occurring in agricultural soils. The present study examined the effect of 1, 3, and 5% doses of Cu0 or Ag0 ENPs stabilized with L-ascorbic acid (suspension pH 2–3) on P ad- and desorption in an agricultural Andisol with total organic matter (T-OM) and with partial removal of organic matter (R-OM) by performing batch experiments. Our results showed that the adsorption kinetics data of H2PO4− on T-OM and R-OM soil samples with and without ENPs were adequately described by the pseudo-second-order (PSO) and Elovich models. The adsorption isotherm data of H2PO4− from T-OM and R-OM soil samples following ENPs addition were better fitted by the Langmuir model than the Freundlich model. When the Cu0 or Ag0 ENPs doses were increased, the pH value decreased and H2PO4− adsorption increased on T-OM and R-OM. The H2PO4− desorption (%) was lower with Cu0 ENPs than Ag0 ENPs. Overall, the incorporation of ENPs into Andisols generated an increase in P retention, which may affect agricultural crop production.

scholarly journals Casting Activity ofScherotheca gigasin No-Till Mediterranean Soils: Role in Organic Matter Incorporation and Influence of Aridity

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Paloma Bescansa ◽  
Iñigo Virto ◽  
Oihane Fernández-Ugalde ◽  
María José Imaz ◽  
Alberto Enrique
Keyword(s):  
Organic Matter ◽  
Agricultural Soils ◽  
Nw Spain ◽  
Organic C ◽  
No Till ◽  
Physico Chemical ◽  
C Stocks ◽  
Casting Activity ◽  
Total Organic C

The behaviour of earthworms, their role in organic matter incorporation into the soil, and the influence of aridity in such processes in arid and semiarid regions have scarcely been studied. In this study, physico-chemical analyses of the casts and the surrounding no-till agricultural soils of three experimental sites representing an aridity gradient in Navarre (NW Spain) were done. The casts were formed by the activity of the only anecic species,Scherotheca gigas(Dugès, 1828), ubiquitous in no-till soils in this region. We observed a significant depletion of clay and higher concentration of total organic C and labile C in the form of particulate organic matter (POM) in the casts as compared to the surrounding soil, suggesting selective ingestion of soil byS. gigas. This, together with the observation of increased concentration in POM with increasing aridity, suggests a major role of this species in the observed progressive gains of organic C stocks in no-till soils in the region.

scholarly journals N<sub>2</sub>O and N<sub>2</sub> losses from simulated injection of biogas digestate depend mainly on soil texture, moisture and temperature

2017 ◽  
Author(s):  
Sebastian Rainer Fiedler ◽  
Jürgen Augustin ◽  
Nicole Wrage-Mönnig ◽  
Gerald Jurasinski ◽  
Bertram Gusovius ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Pore Space ◽  
Inhibitory Effect ◽  
Application Rate ◽  
Organic Fertiliser ◽  
Potential Capacity ◽  
Clayey Silt ◽  
Biogas Digestate ◽  
Silty Soils

Abstract. Biogas digestate (BD) is increasingly used as organic fertiliser, but has a high potential for NH3 losses. Its proposed injection into soils as a counter-measure has been suggested to promote the generation of N2O, leading to a potential trade-off. Furthermore, the effect on N2 losses after injection of BD into soil has not yet been evaluated. We performed a simulated BD injection experiment in a helium-oxygen atmosphere to examine the influence of soil substrate (loamy sand, clayey silt), water-filled pore space (WFPS; 35, 55, 75 %), temperature (2° C, 15° C) and application rate (0, 160, 320 kg N ha−1) as a proxy for row spacing of injection on the emissions of N2O, N2, and CO2. To determine the potential capacity for these gaseous losses, we incubated under anaerobic conditions by purging with helium for the last 24 h of incubation. N2O and N2 emissions as well as the N2 / (N2O + N2) ratio depended on soil type and increased with WFPS and temperature, indicating a crucial role of soil gas diffusivity for the formation of these gases in agricultural soils. However, the emissions did not increase with the application rate of BD, i.e. a broader spacing of injection slits, probably due to an inhibitory effect of the high NH4+ content of BD. Our results suggest that the risk of N2O and N2 losses even after injection of relatively large amounts of BD seems to be small for dry to wet sandy soils and acceptable when regarding simultaneously reduced NH3 emissions for dry silty soils.

scholarly journals Organic matter mineralisation in contrasting agricultural soils amended with sewage sludge .

2014 ◽  
Vol 4 ◽  
Author(s):  
Jose Navarro Pedreño ◽  
Ignacio Gómez Lucas ◽  
Jose Martín Soriano Disla
Keyword(s):  
Organic Matter ◽  
Single Dose ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Agricultural Soils ◽  
Dry Weight ◽  
Soil C ◽  
Multiple Sensor ◽  
Sludge Application

The mineralisation of organic matter (OM) when sewage sludge was used as amendment in 70 contrasting agricultural soils from Spain was analysed. Soils received a single dose of sewage sludge (equivalent to 50t dry weight ha<sup>-1</sup>) and the O<sub>2</sub> consumption was continuously monitored for 30 days using a multiple sensor respirometer in a laboratory experiment. The cumulative O<sub>2</sub> consumption and rates after 8 and 30 days of incubation (O<sub>2 cum</sub> 8d, 30d and O<sub>2 rate</sub> 8d, 30d), the respiratory quotient (RQ), the maximum O<sub>2</sub> rates over the incubation period (O<sub>2 max</sub>) and time from the beginning of the incubation when O<sub>2 max</sub> occurred (T<sub>max</sub>), were determined in both amended and non-amended soils. Sewage sludge application resulted in increased values for O<sub>2 max</sub>, O<sub>2 rate</sub> 8d, and O<sub>2 cum</sub> 30d. Differences were minor for T<sub>max</sub>, RQ 8d and O<sub>2 rate</sub> 30d. A considerable amount of the initial OM applied was mineralised during the first 8 days. Organic matter decomposition (as expressed by O<sub>2 cum</sub> 30d) was favoured in soils with high values of pH, carbonates, soil organic carbon and low values of amorphous Mn. Soils with these characteristics may potentially lose soil C after sewage sludge application.

scholarly journals Zinc availability for corn grown on an oxisol amended with flue dust

2006 ◽  
Vol 63 (6) ◽  
pp. 558-563 ◽  
Author(s):  
Gláucia Cecília Gabrielli dos Santos ◽  
Ronaldo Severiano Berton ◽  
Otávio Antônio de Camargo ◽  
Mônica Ferreira de Abreu
Keyword(s):  
Soil Ph ◽  
Agricultural Soils ◽  
Extraction Methods ◽  
Environmental Risks ◽  
Zinc Availability ◽  
Scheme Design ◽  
Flue Dust ◽  
Free Ion ◽  
Ph Conditions ◽  
Zn Availability

The costs related to the construction and maintenance of industrial landfills, and the environmental risks that they may represent, have increased the interest of several types of industries in studying the possibility of applying residues to agricultural soils. This study evaluates the efficiency of flue dust as a zinc source for corn, and the zinc availability for corn evaluated by four methods. A greenhouse experiment carried out at Campinas, SP, Brazil, evaluated the effect of two zinc sources (flue dust and zinc sulphate), at three rates (5, 50 and 150 mg dm-3), in one soil (Rhodic Hapludox) under two pH conditions (5.0 and 6.0). The treatments were arranged in a randomized factorial scheme design with three replications. Zinc availability indexes were determined by the pH 7.3 DTPA, Mehlich-1, and Mehlich-3 methods. The free Zn2+ activity in soil solution was calculated by the MINTEQ computer model. The extraction methods and the activity of the free ion Zn2+ were equally reliable to evaluate zinc availability in the soil amended with flue dust. More than 70% of the total Zn present in the saturation extract was in the free ion form, and the remainder was mainly complexed to SO4(2-) and OH-, independent of soil pH. Flue dust is a zinc supplier to plants. All tested methods were efficient in evaluating Zn availability for corn, independently of soil pH.

Effective carbon sequestration in Italian agricultural soils by in situ polymerization of soil organic matter under biomimetic photocatalysis

2018 ◽  
Vol 29 (3) ◽  
pp. 485-494 ◽  
Author(s):  
Alessandro Piccolo ◽  
Riccardo Spaccini ◽  
Vincenza Cozzolino ◽  
Assunta Nuzzo ◽  
Marios Drosos ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
In Situ Polymerization ◽  
Agricultural Soils
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