Chemical diversity and molecular signature of soil humic fractions used as proxies of soil quality under contrasted tillage management

Spanish Journal of Soil Science ◽

10.3232/sjss.2021.v11.n1.04 ◽

2021 ◽

Vol 11 ◽

Author(s):

Marco Panettieri ◽

Marco Antonio Jiménez-González ◽

Laura L. De Sosa ◽

Gonzalo Almendros ◽

Engracia Madejón

Keyword(s):

Chemical Composition ◽

Soil Quality ◽

Chemical Diversity ◽

Molecular Signature ◽

Ion Cyclotron Resonance ◽

Tillage Practices ◽

Unsaturated Lipids ◽

The Impact ◽

Humic Fractions

Increasing food production while avoiding the progressive degradation of agricultural soils has become one of the major challenges at a global level. In consequence, the development of sustainable tillage methodologies or cultivation strategies is an important subject of current research. In fact, it has been observed that the implementation of reduced tillage (RT) vs. traditional tillage (TT) in the long term not only improves soil physicochemical properties but also global soil quality in terms of soil health. In particular, the increase of the soil organic carbon (SOC) content under RT conditions is one of the most important factors, but there is little information about the chemical composition and humification level of this carbon, and thus about its persistence at long-term. This is of particular importance considering the policies of carbon sequestration and climate change mitigation, such as the “4 per 1000” initiative. In this study, molecular-level characterization of the humic acid (HA) and fulvic acid (FA) fractions isolated from a soil after 19 years under RT and TT practices was carried out. This study would provide objective descriptors of the impact of these two tillage practices in the chemical composition of the resulting SOC. With this purpose, the potential of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) for assessing changes in the molecular assemblages released from the humic fractions (HA and FA) was examined. The results showed enhanced diversity and chemical richness (expressed as number of molecular formulas) in the composition of SOC under RT. Different tillage-specific compound classes were associated with both tillage practices. As a whole, the humic fraction showed a higher proportion of molecular formulas for lipid and hydroaromatic families in the case of RT compared to TT, while the same fraction under TT showed a greater richness of oxidized protein-derived formulas than RT. In the case of FAs, a similar pattern was observed for hydroaromatic and protein-derived formulas, but the proportion of molecular formulas assigned to unsaturated lipids was higher in TT than in RT. In addition, increased number of formulas for aromatic and condensed aromatic compounds was observed in FAs under TT respect to RT.

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Effect of long term no-till and conventional tillage practices on soil quality

Soil and Tillage Research ◽

10.1016/j.still.2013.03.002 ◽

2013 ◽

Vol 131 ◽

pp. 28-35 ◽

Cited By ~ 99

Author(s):

Irfan Aziz ◽

Tariq Mahmood ◽

K. Rafiq Islam

Keyword(s):

Soil Quality ◽

Conventional Tillage ◽

Tillage Practices ◽

No Till

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Long-term experiments aimed at improving tillage practices

Acta Agronomica Hungarica ◽

10.1556/aagr.58.2010.suppl.1.11 ◽

2010 ◽

Vol 58 (Supplement 1) ◽

pp. 75-81 ◽

Cited By ~ 4

Author(s):

M. Birkás

Keyword(s):

Soil Quality ◽

Crop Production ◽

Root Zone ◽

Material Balance ◽

Weather Conditions ◽

Quality Factors ◽

Surface Protection ◽

Tillage Practices ◽

Climate Stress

The Crop Production Institute of Szent István University carried out soil quality trials in the region of Gödöllő between 1977 and 2002, followed by similar experiments near the town of Hatvan since 2002. Soil quality factors that can be improved by tillage include the looseness of the root zone, the depth of the loosened layer, the duration of the loosened state, the thickness of the compact layer impeding water transport, the soil structure, the level of surface protection, the water intake/water loss balance, the organic material balance and earthworm activity. Optimising these factors can help reduce climate stress, so that extreme weather conditions do not undermine the reliability of farming. Most of the tillage methods elaborated on the basis of the findings of the trials, with the aim of alleviating climate stress, differ from conventional recommendations.

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Tallgrass Prairie Responses to Management Practices and Disturbances: A Review

Agronomy ◽

10.3390/agronomy8120300 ◽

2018 ◽

Vol 8 (12) ◽

pp. 300 ◽

Cited By ~ 3

Author(s):

Pradeep Wagle ◽

Prasanna Gowda

Keyword(s):

Species Richness ◽

Soil Quality ◽

Plant Species ◽

Tallgrass Prairie ◽

Management Practices ◽

The United States ◽

N Fertilization ◽

Native Plant ◽

The Impact

Adoption of better management practices is crucial to lessen the impact of anthropogenic disturbances on tallgrass prairie systems that contribute heavily for livestock production in several states of the United States. This article reviews the impacts of different common management practices and disturbances (e.g., fertilization, grazing, burning) and tallgrass prairie restoration on plant growth and development, plant species composition, water and nutrient cycles, and microbial activities in tallgrass prairie. Although nitrogen (N) fertilization increases aboveground productivity of prairie systems, several factors greatly influence the range of stimulation across sites. For example, response to N fertilization was more evident on frequently or annually burnt sites (N limiting) than infrequently burnt and unburnt sites (light limiting). Frequent burning increased density of C4 grasses and decreased plant species richness and diversity, while plant diversity was maximized under infrequent burning and grazing. Grazing increased diversity and richness of native plant species by reducing aboveground biomass of dominant grasses and increasing light availability for other species. Restored prairies showed lower levels of species richness and soil quality compared to native remnants. Infrequent burning, regular grazing, and additional inputs can promote species richness and soil quality in restored prairies. However, this literature review indicated that all prairie systems might not show similar responses to treatments as the response might be influenced by another treatment, timing of treatments, and duration of treatments (i.e., short-term vs. long-term). Thus, it is necessary to examine the long-term responses of tallgrass prairie systems to main and interacting effects of combination of management practices under diverse plant community and climatic conditions for a holistic assessment.

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Effects of agricultural management on soil organic matter and carbon transformation – a review

Plant Soil and Environment ◽

10.17221/3544-pse ◽

2011 ◽

Vol 52 (No. 12) ◽

pp. 531-543 ◽

Cited By ~ 112

Author(s):

X. Liu ◽

S.J. Herbert ◽

A.M. Hashemi ◽

X. Zhang ◽

G. Ding

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Quality ◽

Crop Rotation ◽

Management Practices ◽

Farmyard Manure ◽

Major Effect ◽

Important Indicator ◽

Tillage Practices ◽

The Impact

Soil organic carbon (SOC) is the most often reported attribute and is chosen as the most important indicator of soil quality and agricultural sustainability. In this review, we summarized how cultivation, crop rotation, residue and tillage management, fertilization and monoculture affect soil quality, soil organic matter (SOM) and carbon transformation. The results confirm that SOM is not only a source of carbon but also a sink for carbon sequestration. Cultivation and tillage can reduce soil SOC content and lead to soil deterioration. Tillage practices have a major effect on distribution of C and N, and the rates of organic matter decomposition and N mineralization. Proper adoption of crop rotation can increase or maintain the quantity and quality of soil organic matter, and improve soil chemical and physical properties. Adequate application of fertilizers combined with farmyard manure could increase soil nutrients, and SOC content. Manure or crop residue alone may not be adequate to maintain SOC levels. Crop types influence SOC and soil function in continuous monoculture systems. SOC can be best preserved by rotation with reduced tillage frequency and with additions of chemical fertilizers and manure. Knowledge and assessment of changes (positive or negative) in SOC status with time is still needed to evaluate the impact of different management practices.

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Distribution of organic carbon in the stable soil humic fractions as affected by tillage management

Canadian Journal of Soil Science ◽

10.4141/s06-059 ◽

2008 ◽

Vol 88 (1) ◽

pp. 99-106 ◽

Cited By ~ 10

Author(s):

Evah W Murage ◽

Paul Voroney

Keyword(s):

C Sequestration ◽

No Tillage ◽

Sampling Depth ◽

Soil C ◽

Tillage Practices ◽

Conventional Ct ◽

Humin Fraction ◽

Humic Fractions ◽

Soil C Sequestration

Soil humus comprises a large and stable pool of soil organic matter (SOM); hence a better understanding of the fate of C in soil humic fractions can provide valuable information for the development of alternative tillage practices that will lead to long-term soil C sequestration. We used δ13C techniques to investigate the effects of tillage on the dynamics of native (C3–C) and corn derived C (C4–C) in fulvic acid (FA), humic acid (HA) and humin fractions. Humic substances were extracted from soils cropped to corn for 11 yr and managed under either conventional (CT) or no-tillage (NT), and from a conventionally tilled soil under > 55 yr of tobacco/rye rotation. No-tillage resulted in higher proportions of C4–C in the upper 5 cm and generally lower C4–C proportions below 5 cm than CT. Up to 31, 27 and 34% of C4–C were assimilated into FA, HA and humin fractions, respectively, indicating that even the humin fraction, often described as passive, old or resistant, acted as a sink of recently added C, and that it is heterogeneous with some of its components being young. Recovery of large proportions of C3–C in the humic fractions demonstrated their importance in the long-term stabilization of SOM. Within each sampling depth, there were no unique differences in the distribution of C3–C among the three humic fractions, suggesting similar turnover of C3–C in all the fractions. Therefore, there was no unique active fraction corresponding with the concept of C pools with defined turnover characteristics used in models of SOM turnover. Key words: Soil humic fractions, corn derived C, native C, δ13C techniques, tillage practices

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Chlorophyll a and chlorophyllide a inside liposomes made of saturated and unsaturated lipids: A possible impact of the lipids microenvironment

Acta periodica technologica ◽

10.2298/apt1445215p ◽

2014 ◽

pp. 215-227 ◽

Cited By ~ 2

Author(s):

Sanja Petrovic ◽

Laura Tugulea ◽

Dejan Markovic ◽

Marcela Barbanta-Patrascu

Keyword(s):

Fatty Acid ◽

Chemical Composition ◽

Chlorophyll A ◽

Fluorescence Polarization ◽

Molecular Sensors ◽

Polarization Spectroscopy ◽

Unsaturated Lipids ◽

Spectral Behaviour ◽

Emission Quenching ◽

The Impact

The aim of this work was to examine a possible impact of liposomes lipids microenvironment, dictated by a chemical composition of the fatty acid branches, on incorporation and spectral behaviour of chlorophyll a, and its derivative, chlorophyllide a inside small liposomes. The liposomes with the incorporated chlorophylls were made of dimirystoyl phosphatidylcholine (DMPC), and unsaturated phosphatidylcholine (PC), containing significant fractions of unsaturated fatty acid moieties. In order to achieve the goal, both absorption and fluorescence polarization spectroscopy were applied, and the obtained data for the two incorporated pigments, which play a role of molecular sensors, were compared. In addition, quercetin, a well-known antioxidant, was used as the (chlorophylls) emission quencher, in order to estimate the type of environment sensed by the two pigments for the two liposomes that differ in chemical composition. The results, based primarily on fluorescence polarization data have shown that the emissions as well as the emission quenching were notably affected by a change in the lipids? chemical composition. That is an indirect proof of the impact of the liposomes microenvironment on the incorporated pigments? spectral behaviour.

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Plasticenta: Microplastics in Human Placenta

10.1101/2020.07.15.198325 ◽

2020 ◽

Author(s):

Antonio Ragusa ◽

Alessandro Svelato ◽

Criselda Santacroce ◽

Piera Catalano ◽

Valentina Notarstefano ◽

...

Keyword(s):

Chemical Composition ◽

Human Health ◽

Endocrine Disruptors ◽

Human Placenta ◽

The Other ◽

Long Term Effects ◽

Living Organisms ◽

The Impact ◽

First Time

Summary paragraphMicroplastics are particles smaller than five millimetres obtained from the degradation of plastic objects abandoned in the environment. Microplastics can move from the environment to living organisms and, in fact, they have been found in fishes and mammals.Six human placentas, prospectively collected from consenting women with uneventful pregnancies, were analyzed by Raman Microspectroscopy to evaluate the presence of microparticles. Detected microparticles were characterized in terms of morphology and chemical composition.12 microparticles, ranging from 5 to 10 μm in size, were found in 4 out of 6 placentas: 5 in the foetal side, 4 in the maternal side and 3 in the chorioamniotic membranes. All the analyzed microparticles were pigmented: three of them were identified as stained polypropylene, while for the other nine it was possible to identify only the pigments, which are all used for man-made coatings, paints and dyes.Here we show, for the first time, the presence of microparticles and microplastics in human placenta. This sheds new light on the impact of plastic on human health. Microparticles and microplastics in the placenta, together with the endocrine disruptors transported by them, could have long-term effects on human health.

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Suppressed, but Not Forgotten

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000033 ◽

2011 ◽

Vol 70 (1) ◽

pp. 5-11 ◽

Cited By ~ 8

Author(s):

Beat Meier ◽

Anja König ◽

Samuel Parak ◽

Katharina Henke

Keyword(s):

Memory Trace ◽

Thought Suppression ◽

Test Phase ◽

Indirect Test ◽

Final Test ◽

Test Experiment ◽

And Control ◽

Cue Words ◽

The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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