Papers by Eleonora Bonifacio
Effetto dell’inerbimento permanente e della lavorazione autunnale sull’aggregazione e sulledinamiche della sostanza organica in vigneto
XIII Convegno AISSA Nutrire il pianeta con l'agricoltura: il punto di vista dei ricercatori, 2015
First geostatistical estimate of the petroleum fallout on soils after the Trecate accident (NW Italy)
Stabilizzazione della sostanza organica in suoli a diverso grado di podlizzazione
Convegno Nazionale della Società Italiana di Scienza del Suolo, LA COMPLESSITA' del SUOLO, 2011
The influence of crystalline and poorly crystalline iron oxides on the surface area of Podzol and Luvisol B horizons
40° Congresso Nazionale SISS "Suoli di Qualità per una Vita di Qualità", 2015
Soils in Pleistocene large-scale sorted striped and blockstreams and their paleoclimatic implications
EQA, 2011
Carbon isotopic analysis is a useful tool for investigating paleoenvironments, as the pedogenic c... more Carbon isotopic analysis is a useful tool for investigating paleoenvironments, as the pedogenic carbonate δ 13 C is related to δ 13 C SOM and to the proportions of C 3 /C 4 plants. In this work we interpreted the paleoenvironmental conditions at the time of carbonate precipitation in soils formed under different climates and during different geological ages. Samples were taken from a Bk (PR1, Holocene) and from two Bkm horizons (PR2 and PR3, Pleistocene). When the mean δ 13 C plant values and the most plausible paleotemperatures were used in the evaluation, PR1 showed a lower percentage of C 4 plants (48%) than Pleistocene soils (~53%), in agreement with paleoclimate changes. When instead the δ 13 C values of current plants were used for PR1, C 4 plants ranged from 59 (12°C) to 66% (18°C), suggesting two possible interpretations: either plant species changed during the Holocene, or the plant mean values normally used in the literature are not suitable for Pleistocene reconstructions
Dynamics of organic matter in a 65 years natural re-vegetation of mining spoil-banks with Pinus Sylvestris L. in Northern Russia
Electrophoretic mobility and clay mineralogy in some fragipan and non-fragipan horizons
Modelling aggregate breakdown in some Italian Alfisols
Stabilizzazione della sostanza organica in suoli a diverso grado di podzolizzazione
Rimozione di carbonati, sostanza organica e ossidi di ferro
Per studiarne la mineralogia, la frazione terra fine (diametro equivalente delle particelle &... more Per studiarne la mineralogia, la frazione terra fine (diametro equivalente delle particelle < 2 mm) del suolo viene normalmente suddivisa nelle classi granulometriche sabbia, limo ed argilla, cui corrispondono notevoli differenze di composizione mineralogica riferibili ai processi di alterazione della roccia madre alla superficie terrestre. Nella sabbia, ed in modo particolare nella frazione pi\uf9 grossolana della sabbia (2-0.2 mm), predominano, infatti, i minerali primari ereditati dal parent material, nella frazione argillosa (< 0.002 mm) i minerali secondari, mentre nella frazione limosa (0.02-0.002 mm) entit\ue0 mineralogiche primarie e secondarie sono presenti in quantit\ue0 intermedie. La frazione granulometrica argilla, ed ancor pi\uf9 l\u2019argilla fine (< 0.001 mm), sono quindi le pi\uf9 adatte ad essere studiate con lo scopo di accertare la formazione nel suolo di nuovi minerali, in seguito a fenomeni di neogenesi (dissoluzione di minerali e precipitazione di prodotti dalla soluzione) o di trasformazione di fasi preesistenti. La scarsa cristallinit\ue0 dei minerali argillosi del suolo rispetto a quelli litogenici ne renderebbe difficile l\u2019identificazione nel campione non separato in classi granulometriche. Inoltre, le differenze in composizione mineralogica delle diverse classi vanificherebbero i tentativi di interpretazione delle variazioni mineralogiche a fini pedogenetici. Nel suolo le particelle minerali sono generalmente presenti non come particelle singole, ma unite a formare aggregati in seguito all\u2019azione cementante di sostanze quali la sostanza organica, i carbonati, gli ossidi di ferro e di alluminio. L\u2019uso di agenti chimici che selettivamente rimuovono i cementi liberando le singole particelle prima della separazione del campione di terra fine in classi granulometriche \ue8 considerato un prerequisito necessario ai fini di una corretta identificazione delle fasi mineralogiche presenti. E\u2019 importante tenere conto che i trattamenti finalizzati all\u2019eliminazione delle sostanze cementanti possono, tuttavia, provocare modificazioni nella organizzazione strutturale e nelle propriet\ue0 chimiche dei fillosilicati, con conseguente variabilit\ue0 delle fasi identificate in funzione dei metodi adottati. A tale proposito sono reperibili in letteratura diversi lavori che, valutando i meccanismi di azione degli agenti chimici maggiormente utilizzati nei trattamenti preliminari alla separazione in classi granulometriche, indicano quali fasi argillose sono maggiormente vulnerabili. In tutti i casi, l\u2019elevata variabilit\ue0 che caratterizza i minerali della frazione argillosa del suolo non consente una valutazione a priori dell\u2019effetto del pre-trattamento. Anche il trattamento di rimozione della sostanza organica mediante ossidazione con perossido d\u2019idrogeno non \ue8 esente da controindicazioni. L\u2019acidit\ue0 che si libera durante il processo, con conseguente abbassamento del valore di pH, pu\uf2 indurre la parziale solubilizzazione di fasi minerali a scarso ordine cristallino. La non completa ossidazione della componente organica pu\uf2 portare ad accumulo nel residuo minerale di ossalati di calcio. In questo capitolo vengono considerati e descritti i procedimenti analitici comunemente impiegati per rimuovere dalla frazione terra fine del suolo i carbonati, la sostanza organica e gli ossidi di ferro amorfi e cristallini. Alla luce di quanto esposto precedentemente e tenendo sempre presente che non esistono tecniche di dissoluzione selettiva, ma solo tecniche di dissoluzione preferenziale, si consiglia di non eseguire pre-trattamenti di routine sui campioni da sottoporre ad analisi mineralogica, ma di valutarne di volta in volta l\u2019applicabilit\ue0 sulla base del tipo di indagine che si intende effettuare
Role of iron oxides in the fate of inositol phosphates in soil
Caratterizzazione della porosità in suoli calcarei tramite adsorbimento di N2 e porosimetria ad intrusione di Hg
Pedologia, chimica e stoccaggio di carbonio nei suoli forestali Europei: Il progetto Biosoil-Soil
Simulating wildfires with lab-heating experiments: Drivers and mechanisms of water repellency in alpine soils
Geoderma, 2021
Abstract Wildfires induce deep modifications in soils. Water Repellency (WR) is one of the prime ... more Abstract Wildfires induce deep modifications in soils. Water Repellency (WR) is one of the prime edaphic properties experiencing alterations upon heating. Despite occurrence, extent and persistence of burning-induced soil WR has been extensively discussed, the dynamics at the basis of its formation (and loss) are still widely unclear. The vast majority of research on this topic has been conducted in the Mediterranean area, even if alpine environments are far from being untouched by fires. Alpine soils are less developed than Mediterranean ones, and differ in mineralogy and composition of organic matter (and thereby present different interactions). We thus wanted to clarify some key mechanisms regulating WR thermal alterations in an understudied environment. Our sampling design aimed at collecting soils representative of the Western Alps. Sample heating was performed in the lab at fixed temperatures (up to 300 °C), on a set of A horizons developed under pine and beech forest covers. Water Drop Penetration Time (WDPT) and Sessile Drop Contact Angle (CA) were used to test WR. Soils were analyzed in terms of organic matter (OM), pH, serpentine relative abundance, texture and DCB-extractable iron (Fe). WR was found to be extremely variable. Soils rich in OM, especially if containing abundant aromatic compounds, were found to be the most hydrophobic at room temperature. In samples exhibiting an increase in WR upon burning, repellency was maximized in correspondence of 200 °C. WR was drastically lost when samples were heated at temperatures greater than 200 °C. Above this threshold, pH systematically increased and the percentage of organic carbon (OC) sharply decreased. The change in pH is likely to have triggered an increase in the negative charge of mineral surfaces, resulting in a significant OM desorption and OC oxidation, eventually leading to a super-hydrophilic behavior in soil. The present investigation evidenced the susceptibility of Alpine soils towards thermal alteration, addressing the factors (organic matter composition and mineralogy) that mostly influence the hydrophobic behavior of these soils.
How are mineral and organic phases regulating burning-induced soil water repellency? Unravelling the crucial dynamics occurring in the Alps even at moderate fire intensities
<p>Wildfires play the role of ecosystem shapers in the majority of terrestr... more <p>Wildfires play the role of ecosystem shapers in the majority of terrestrial biomes, altering canopy and litter cover and imposing strong modifications on soils. Organic matter (OM) content and composition, mineralogy, pH, aggregate stability and water repellency (WR) are among the main edaphic properties to be affected by heat. Various studies dealt with occurrence, extent and persistence of burning-induced soil WR, but the dynamics at the basis of its formation (and loss) are still widely unclear. In addition, the vast majority of research on this topic has been carried out in the Mediterranean, even if alpine environments are far from being untouched by fires. Our aims were therefore to provide insight into the key mechanisms regulating WR thermal alterations in a relatively understudied environment.</p><p>Our sampling design aimed at collecting soils representative of the Western Italian Alps. Charring was simulated in the lab, at increasing temperatures (up to 300° C), on a set of A soil horizons developed under pine and beech forest covers. Water drop penetration time (WDPT) was employed to test WR persistence. Soils were analyzed in terms of organic carbon (OC) and nitrogen contents, pH, texture and iron (Fe) oxides composition (Fe-DCB and Fe-pyrophosphate extracted). Fe-speciation and OM composition of some selected samples were further characterized using Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy and Fourier transform-infra red (FT-IR) spectroscopy, respectively.</p><p>WR was found to be extremely variable, event at room temperature. For samples exhibiting an increase in WR upon burning intensity, maximum repellency was observed at 200° C. OC abundance (%) and coarse texture were found to be the main drivers of hydrophobicity in soil. WR was drastically lost when samples were exposed to temperatures higher than 200°C. Above this threshold, pH systematically increased and OC (%) sharply decreased. The increasingly negative charge of mineral surfaces, mirrored by pH increase, seems to result in a significant C volatilization by OM desorption, eventually leading to a super-hydrophilic behavior in soil.</p><p>Fe EXAFS allowed to evaluate different thermal-dictated pathways of Fe-speciation. The formation of more crystalline Fe-forms (e.g. hematite, meghemite) was observed above 200° C. Even though a reduction in surface area should be expected when observing an increase in crystallization degree (potentially giving rise to greater WR), OM adhesion to mineral surfaces seems to be inhibited by the change induced in their charge. A reduction in the OM-bound Fe pool (pyrophosphate extracted) above 200° C could be appreciated, supporting the interpretation of oxy-hydroxides transformations and OC (%) loss.  </p><p>The current investigation has been carried out to capture an in-depth picture of wildfire impacts on alpine soils, targeting factors responsible for WR enhancement and shred. Identifying the mechanisms regulating wildfire-related WR is a key issue, as the formation of hydrophobic layers in soil highly favors its erosion. Addressing such matters is crucial to tackle the issue of ecosystems recovery, considering that climate-change-related alterations in wildfires regimes are already causing the occurrence of more frequent and disruptive fires.</p>
Plant and Soil, 2019
Aims In deglaciated surfaces, lithology influences habitat development. In particular, serpentini... more Aims In deglaciated surfaces, lithology influences habitat development. In particular, serpentinite inhibits soil evolution and plant colonization because of insufficient phosphorus (P) content, among other stressful properties. In nutrient-poor environments, ectomycorrhizal fungi (EMF) play a key role exploring the soil for P beyond the rhizosphere. In this study, we followed the role of EMF in accessing inorganic and organic P along two proglacial soil chronosequences in the Alps (NW Italy), respectively characterized by pure serpentinite till and serpentinite mixed with 10% of gneiss, and colonized by European Larch. Methods The access to inorganic and organic P forms by EMF was studied using specific mesh-bags for fungal hyphae entry, filled with quartz sand and inorganic phosphate (Pi) or myoinositolhexaphosphate (InsP6) adsorbed onto goethite. They were incubated over 13 months at the organic/mineral horizon interface. After harvesting, EMF colonization via ergosterol analysis and the amount of P and Fe removed from mesh bags were measured. Results Ergosterol increased along the two chronosequences with slightly greater values on serpentinite and in Pi-containing bags. Up to 65% of Pi was removed from mesh-bags, only partly accompanied by a parallel release of Fe. The amount of InsP6 released was instead less than 45% and mostly removed with goethite. Conclusions 3 The results suggest that, in extremely P-poor environments, EMF are able to release both inorganic and organic P forms from highly stabilized associations.
Geoderma, 2017
Fragipan is a dense and usually brittle subsurface soil horizon, limiting the penetration of root... more Fragipan is a dense and usually brittle subsurface soil horizon, limiting the penetration of roots and the infiltration of water. The genesis of fragipan is still unclear, but a general agreement exists on the importance of wet-dry cycles. In addition, in argillic Bx horizon, the presence of cations affecting the clay dispersion/flocculation behaviour might be a key factor in fragipan dynamics. In order to gain knowledge on the specific effect of alternating moisture conditions on the evolution of aggregates collected from a Btx horizon, we evaluated the variations of physical properties caused by a wet-dry cycle using both deionized and Ca-enriched water on the 1-2 mm aggregate, and on newly formed aggregates (i.e. 2-5 and > 5 mm size classes) obtained after a lab experiment. The results were compared with a Bt horizon that did not show fragipan properties. Btx and Bt samples were collected from a Typic Fragiudalf developed on fluvio-glacial terraces in NW Italy. The two horizons had comparable clay content (around 13%), and their mineralogical composition was dominated by hydroxy-interlayered vermiculite and smectite. The fragipan 1-2 mm aggregates showed a low clay dispersion ratio (11.5%) before the treatments, together with low volume of macropores (74 mm 3 g − 1), high volume of mesopores (111 mm − 3 g − 1), high slaking (30.1%), close packing of coarse particles and open arrangement of fine particles. The water treatment increased the amount of flocculated-clay in the new-aggregates, and Catreatment enhanced clay flocculation both in the newly formed and in the remaining 1-2 mm aggregates. The clay flocculation induced a denser arrangement of clay particles (≥ 0.44), and a consequent reduction of mesopores (from 56.2 to 66.1 mm − 3 g − 1), combined with the opening of the coarser particles packing (≤0.78). This new particle arrangement did not correspond to the specific combination of coarse/fine particles arrangement of fragipan. The relative percentage of slaking also decreased. Therefore, upon both deionized water and CaCl 2 wetting and drying, the newly formed aggregates (i.e., 2-5 and > 5 mm) from disturbed fragic materials, as well as those that did not take part in the new aggregate formation (1-2 mm), did not show the specific physical properties of fragipan. The simulation of wet and dry cycle acted on clay colloidal behaviour, and the results suggested the degradation, rather than the enhancement, of Btx physical properties measurable in laboratory.
Applied Soil Ecology, 2017
Soil erosion depends mainly on its intrinsic vulnerability (soil erodibility), which is represent... more Soil erosion depends mainly on its intrinsic vulnerability (soil erodibility), which is represented by the K factor of the RUSLE equation. Soil erodibility is strictly related to soil structure, which depends mostly on soil particle-size distribution and organic and inorganic binding agents. Soil erodibility can be estimated through soil aggregate stability measurements. However, the effects of different humus forms on soil erodibility and aggregate stability are poorly understood. In this study, we evaluate the influence of different humus forms on these parameters, and consequently on soil susceptibility to erosion. In the Western Italian Alps, 67 sites were selected on different substrata under common forest vegetation types. In all sites, soil profiles and humus forms were described and classified. Soil samples from the upper mineral horizons (A or E) were analysed (SOM content, water aggregate stability that measures aggregates loss) and soil erodibility K factor was calculated. The results showed that surface mineral horizons in soils with Mor humus were the most susceptible to erosion because they had the greatest values of K and aggregates loss, and their surface mineral horizons were characterized by the lowest SOM content. Conversely, surface mineral horizons in soils with Amphi, which had the greatest SOM content, were the least susceptible to erosion, as demonstrated by the lowest K values and limited aggregates loss. Mull and Moder forms showed intermediate behaviours. Despite a similar SOM content as Mulls, Moders showed a slightly greater aggregates loss. At low SOM content, the aggregates loss increased but it varied significantly among the humus forms. In Moders, SOM variations induced large changes in aggregates losses while Amphi forms were the least influenced by SOM. These results show that the intrinsic characteristics of humus forms, derived from the biological factors to which they are associated, influence soil erodibility and aggregate stability and consequently soil susceptibility to water erosion.
Soil Research, 2016
Vineyard soils are typically characterised by poor development, low organic matter content and st... more Vineyard soils are typically characterised by poor development, low organic matter content and steep slopes. Consequently, they have a limited capacity for conservation of organic matter that is weakly bound to the mineral soil phase. Under such conditions, establishment of permanent grass may improve soil quality conservation. The aim of this study was to evaluate the effects of permanent grass v. single autumn tillage on soil structure and organic matter dynamics in a hilly vineyard. During the periods 1994–1996 and 2010–2012, soil samples were collected three times per year, in different seasons. Aggregate stability analyses and organic matter fractionation were performed. The effects of grass cover on soil recovery capacity after tillage disturbance were slow to become apparent. Slight increases in aggregate resistance and organic matter contents were visible after 3 years, and the two plots (permanent grass/previously tilled) showed a large decrease of aggregate losses and incr...
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Papers by Eleonora Bonifacio