soil systems
Recently Published Documents


TOTAL DOCUMENTS

533
(FIVE YEARS 116)

H-INDEX

44
(FIVE YEARS 8)

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 130
Author(s):  
Dario Fornara ◽  
Elizabeth M. E. Ball ◽  
Christina Mulvenna ◽  
Henry Reyer ◽  
Michael Oster ◽  
...  

The over-supplementation of animal feeds with phosphorus (P) within livestock-production systems leads to high rates of P excretion and thus to high P loads and losses, which negatively impact the natural environment. The addition of phytase to pig and poultry diets can contribute to reducing P excretion; however, cascading effects of phytase on plant–soil systems remain poorly understood. Here, we addressed how three different diets containing various levels of exogenous phytase, i.e., (1) no-phytase, (2) phytase (250 FTU), and (3) superdose phytase (500 FTU) for pigs (Sus scrofa domesticus) and broilers (Gallus gallus domesticus) might affect P dynamics in two different plant–soil systems including comfrey (Symphytum ×uplandicum) and ryegrass (Lolium perenne). We found that differences in phytase supplementation significantly influenced total P content (%) of broiler litter and also pig slurry (although not significantly) as a result of dietary P content. P Use Efficiency (PUE) of comfrey and ryegrass plants was significantly higher under the intermediate ‘phytase’ dose (i.e., commercial dose of 250 FTU) when compared to ‘no-phytase’ and ‘superdose phytase’ associated with pig slurry additions. Soil P availability (i.e., water soluble P, WSP) in both comfrey and ryegrass mesocosms significantly decreased under the intermediate ‘phytase’ treatment following pig slurry additions. Dietary P content effects on P losses from soils (i.e., P leaching) were variable and driven by the type of organic amendment. Our study shows how commercial phytase levels together with higher dietary P contents in pig diets contributed to increase PUE and decrease WSP thus making the plant–soil system more P conservative (i.e., lower risks of P losses). Our evidence is that dietary effects on plant–soil P dynamics are driven by the availability of P forms (for plant uptake) in animal excretes and the type of organic amendment (pig vs. broiler) rather than plant species identity (comfrey vs. ryegrass).


SOIL ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 785-809
Author(s):  
Carrie L. Thomas ◽  
Boris Jansen ◽  
E. Emiel van Loon ◽  
Guido L. B. Wiesenberg

Abstract. Despite the importance of soil organic matter (SOM) in the global carbon cycle, there remain many open questions regarding its formation and preservation. The study of individual organic compound classes that make up SOM, such as lipid biomarkers including n-alkanes, can provide insight into the cycling of bulk SOM. While studies of lipid biomarkers, particularly n-alkanes, have increased in number in the past few decades, only a limited number have focused on the transformation of these compounds following deposition in soil archives. We performed a systematic review to consolidate the available information on plant-derived n-alkanes and their transformation from plant to soil. Our major findings were (1) a nearly ubiquitous trend of decreased total concentration of n-alkanes either with time in litterbag experiments or with depth in open plant–soil systems and (2) preferential degradation of odd-chain length and shorter chain length n-alkanes represented by a decrease in either carbon preference index (CPI) or odd-over-even predominance (OEP) with depth, indicating degradation of the n-alkane signal or a shift in vegetation composition over time. The review also highlighted a lack of data transparency and standardization across studies of lipid biomarkers, making analysis and synthesis of published data time-consuming and difficult. We recommend that the community move towards more uniform and systematic reporting of biomarker data. Furthermore, as the number of studies examining the complete leaf–litter–soil continuum is very limited as well as unevenly distributed over geographical regions, climate zones, and soil types, future data collection should focus on underrepresented areas as well as quantifying the transformation of n-alkanes through the complete continuum from plant to soil.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4069
Author(s):  
Franja Prosenc ◽  
Pia Leban ◽  
Urška Šunta ◽  
Mojca Bavcon Kralj

Microplastic pollution is globally widespread; however, the presence of microplastics in soil systems is poorly understood, due to the complexity of soils and a lack of standardised extraction methods. Two commonly used extraction methods were optimised and compared for the extraction of low-density (polyethylene (PE)) and high-density microplastics (polyethylene (PET)), olive-oil-based extraction, and density separation with zinc chloride (ZnCl2). Comparable recoveries in a low-organic-matter matrix (soil; most >98%) were observed, but in a high-organic-matter matrix (compost), density separation yielded higher recoveries (98 ± 4% vs. 80 ± 11%). Density separation was further tested for the extraction of five microplastic polymers spiked at different concentrations. Recoveries were >93% for both soil and compost, with no differences between matrices and individual polymers. Reduction in levels of organic matter in compost was tested before and after extraction, as well as combined. Double oxidation (Fenton’s reagent and 1 M NaOH) exhibited the highest reduction in organic matter. Extracted microplastic polymers were further identified via headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS). This method has shown the potential for descriptive quantification of microplastic polymers. A linear relationship between the number of particles and the signal response was demonstrated for PET, polystyrene (PS), polyvinyl chloride (PVC), and PE (R2 > 0.98 in alluvial soil, and R2 > 0.80 in compost). The extraction and identification methods were demonstrated on an environmental sample of municipal biowaste compost, with the recovery of 36 ± 9 microplastic particles per 10 g of compost, and the detection of PS and PP.


2021 ◽  
Author(s):  
◽  
Michael Charles Harold McKubre

<p>Work is reported of the development of clay and resin model soil systems for the observation of induced polarisation phenomena. A measuring technique is developed to determine impedance spectra of such models over the frequency range of 10-3 to 10 4 Hz, and a variety of model cells tested varying such parameters as temperature, electrolyte type and concentration, and bead size of resin. An increase in impedance with decrease in frequency is observed, consistent with field observation of the induced polarisation phenomenon associated with moist, non-mineralised soils, and a number of empirical observations of the form of this are made.</p>


2021 ◽  
Author(s):  
◽  
Michael Charles Harold McKubre

<p>Work is reported of the development of clay and resin model soil systems for the observation of induced polarisation phenomena. A measuring technique is developed to determine impedance spectra of such models over the frequency range of 10-3 to 10 4 Hz, and a variety of model cells tested varying such parameters as temperature, electrolyte type and concentration, and bead size of resin. An increase in impedance with decrease in frequency is observed, consistent with field observation of the induced polarisation phenomenon associated with moist, non-mineralised soils, and a number of empirical observations of the form of this are made.</p>


CATENA ◽  
2021 ◽  
pp. 105876
Author(s):  
Patricia Merdy ◽  
Mohamed Gamrani ◽  
Célia R. Montes ◽  
Ary T. Rezende Filho ◽  
Laurent Barbiero ◽  
...  

2021 ◽  
Author(s):  
Zhen Xu ◽  
Chao Song ◽  
Yue Zhu ◽  
Chi Zhang ◽  
Xiaoyue Huang

Abstract Polybrominated diphenyl ethers (PBDEs) are toxic to humans and can easily accumulate in the environment. Nanoscale zero-valent iron (NZVI) and modified NZVI have been developed to remediate PBDE contamination. However, their degradation in soil systems and their microbial toxicity have not been widely explored. In this study, NZVI supported on biomass carbon was applied to remove decabromodiphenyl ether (BDE-209) from contaminated soil. A removal efficiency of 100% was achieved within 384 h as BDE-209 reacted with 0.10 g/g soil biomass carbon NZVI particles (BC–NZVI) at pH 7.00. The reaction followed pseudo-first-order kinetics, and the BDE-209 removal efficiency increased with increasing BC–NZVI dosage and decreasing initial BDE-209 concentration, pH, and moisture content. Biological activity assays (dehydrogenase activity and soil basal respiration) were conducted to provide a preliminary risk assessment of the BC–NZVI application in BDE-209 contaminated soil. The results demonstrate that BC–NZVI has a strong potential for in situ remediation of organic-contaminated soil.


Sign in / Sign up

Export Citation Format

Share Document