Stefania Cocco

Changes induced by the roots of Erica arborea L. to create a suitable environment in a soil developed from alkaline and fine-textured marine sediments

Background and aimsWe report on the modifications induced by the roots of Erica arborea L. on a soil derived from alkaline and fine-textured marine sediments.MethodsPhysical, chemical, mineralogical and biochemical properties of bulk soil and of the rhizosphere of Erica were characterised to evaluate its role on soil development.ResultsOnce the upper horizons had been decarbonated because of geomorphic and pedogenic processes, Erica colonised the soil and progressively modified it through the activity of roots. In the upper horizons, there was no difference between rhizosphere and bulk soil for pH, organic C and exchangeable Al and H. At depth, pH, organic C and exchangeable Al and H differed between rhizosphere and bulk soil. The weathering reactions induced by the Erica roots caused a relative quartz enrichment in the rhizosphere compared with the bulk soil. In the E, EB and Bw horizons, the microbial community of the rhizosphere appeared better adapted than in the underlying 2Bw horizons, where the rhizospheric microorganisms were poorly adapted as these horizons represented the boundary between acid and sub-alkaline soil environments.ConclusionsThe activity of Erica roots modified soil properties so to produce more favourable conditions for itself and the rhizosphere microflora.

Evaluation of Erosion Intensity and Some of Its Consequences in Vineyards from Two Hilly Environments Under a Mediterranean Type of Climate, Italy

Giuseppe Corti1, Eugenio Cavallo2, Stefania Cocco1, Marcella Biddoccu2, Giorgia Brecciaroli1 and Alberto Agnelli3 1Dipartimento di Scienze Ambientali e delle Produzioni Vegetali, Facoltà di Agraria. Università Politecnica delle Marche, Ancona; 2Istituto per le Macchine Agricole e Movimento Terra, Consiglio Nazionale delle Ricerche, Torino; 3Dipartimento di Scienze Agrarie ed Ambientali, Facoltà di Agraria. Università degli Studi di Perugia, Perugia; Italy

Characteristics of rhizosphere soil from natural and agricultural environments

ABSTRACT In the first part of this chapter, we present an overview of the methodologies adopted to study the rhizosphere soil, focusing on the protocols devised for its separation. For these methodologies and protocols, we also discuss the advantages and disadvantages inherent in their use. The sections of the chapter are dedicated to reports on three case studies, where the bulk and rhizosphere soil of three arboreal species are compared and contrasted. The first case study deals with the strategy used by Genista aetnensis Biv. to colonize the inhospitable volcanic soils on the flanks of Mount Etna (Sicily, Italy). In this environment, Genista are able to overcome the low availability of nutrients through forcing the roots to excrete oxalic acid, and to preserve P by the hosting of a microbial population in the rhizosphere soil that is responsible for the biological cycling of P. As a by-product of the weathering promoted by the roots, the yellowish-coloured collar around them, which is due to the presence of amorphous Fe-oxyhydroxides, reveals the thickness of the rhizosphere soil. The second case presented deals with the ability of Erica arborea L. to colonize a soil derived from alkaline marine deposits in Central Italy. The Erica plants, which are established in this environment due to the formation of superficial acid horizons, have been able to modify the upper 60 cm of soil through root excretion of organic acids until the differences between bulk and rhizosphere are removed. The roots of Erica are now colonizing the horizon underneath, where the rhizosphere soil is more acidic than the bulk. At deeper levels, carbonates persist and roots of Erica are rare. The final case study reports on the chemical fractionation of lanthanides in bulk and rhizosphere soil of adult vines ( Vitis vinifera L.) from two vineyards, one in Tuscany (Italy) and the other in Galicia (Spain). In these soils, the presence of lanthanides has been ascribed mostly to the long-lasting practices of cultivation and, in particular, to the use of fertilizers and the deep mechanical working of the soil, which have greatly affected the soil characteristics over the centuries. The chemical fractions more involved in the binding of lanthanides have resulted in the organic matter and the Fe-oxyhydroxides. In both soils, root activity since the planting of the vineyard (some decades ago) has been able to modify the chemical fractionation of lanthanides within the horizons, with a small effect on the redistribution throughout the profile.

Italian Soil Management from Antiquity to Nowadays

This chapter begins with a short recollection of the general concepts of soil management and, thus, reports of the different methods to rate soil quality. Both these sections set the stage to a wide presentation of an historical overview of soil management that in Italy has been going on from the beginning of agriculture to nowadays. In this way, recent archaeological observations have allowed to proposed original theories about the genesis of badland landscapes, so diffuse in Italy. Particular attention has also been done on the impact of European directives on the soil and land management, taking into consideration all the directives promulgated from the beginning of the European Union. The chapter also reports of the land set-up systems devoted to soil and water conservation, many of them invented in Italy, and of the different soil managements adopted in different Italian physiographic agro-ecosystems: high-alpine environments, pre-alpine fringe, Po plain, Apennines, southern Italy and the two great islands of Sardinia and Sicily.

Snow vole (Chionomys nivalis Martins) affects the redistribution of soil organic matter and hormone‐like activity in the alpine ecosystem: ecological implications

Abstract In alpine environments, colonies of snow vole (Chionomys nivalis Martins) cause strong pedoturbation, which may affect humification process and soil organic matter (SOM) cycling, with repercussions on the hormone‐like activity of organics. We investigated the effect of snow vole pedoturbation on the chemical and spectroscopic features of soil organic fractions, and the potential hormone‐like activity of humic and fulvic acids (HA, FA). The study site was located on the high‐mountain environment of the Majella massif (central Italy). Pedoturbated and regular soils were morphologically described and characterized for pH and content of total organic carbon, total extractable carbon, HA, and FA. Both HA and FA were extracted and investigated using attenuated total reflectance/Fourier transform infrared (ATR/FTIR), nuclear magnetic resonance with high‐resolution magic angle spinning (HRMAS‐NMR), and 1H‐13C heteronuclear single quantum coherence (HSQC). HA and FA were also tested for their auxin‐like and gibberellin‐like activities. Results provide evidences that bioturbated and regular soils contain a poorly decomposed SOM, but HA and FA with a well‐defined molecular structure. The HA and FA from both bioturbated and regular soils show a hormone‐like activity with a different allocation along the soil profile. In the regular soil, the highest auxin‐like activity was shown by HA and FA from Oe1 horizon, while gibberellin‐like activity was expressed by FA from Oe2 horizon. Burrowing activity determines a redistribution of organics throughout the profile with a relatively high auxin‐like activity in the FA from straw tunnel wall (STW) and gibberellin‐like activity in the HA from vole feces (VF). The relative high presence of carboxylic acids, amides, proteins, and amino acids in the FA from STW and the aromatic moieties in the HA from VF put evidences for their different behavior. The fact that snow vole activity has modified the chemical and biological properties of SOM in these soils otherwise considered governed only by low temperature has important ecological implications such as the preservation of soil fertility and vegetal biodiversity.

Holm oak (Quercus ilex L.) rhizosphere affects limestone-derived soil under a multi-centennial forest

Background and AimsThe activity of roots and associated microorganisms plays a key-role in soil formation and evolution, but we lack of knowledge on the quality and extent of the “rhizosphere effect” in the different soil horizons. The aim of this study was to assess the interactions between rhizosphere processes and genetic horizons in a forest (Quercus ilex L.) soil developed from limestone. Specifically, we tested (a) if the rhizosphere effect was significant in all the horizons of the soil profiles, and (b) if the intensity of the rhizosphere effect was associated to structure, composition and activity of the microbial community.MethodsBulk and rhizosphere soils were characterized by physical, mineralogical, chemical and biological (microbial activity and community structure) analyses.ResultsThroughout the soil profile, the rhizosphere processes affected properties like particle-size distribution and soil structure, mineralogy, pH, and organic C and total P content. Conversely, amounts of exchangeable Ca, Mg and K, iron oxides, available P, and total nitrogen showed no significant change. As for the microbial community, its structure and metabolic activity differed between rhizosphere and bulk only in the core of the solum (2Bwb and 3Bwb horizons).ConclusionsThe main processes controlling the intensity of the rhizosphere effect on the soil horizons were root activity, soil faunal perturbation and slope dynamics. While root activity impacted the whole soil profile, although to a lesser extent at depth, the influence of fauna and slope was confined atop the profile. It follows that long-term changes due to root activity and associated microbial community were more strongly expressed in the core of the solum, not at the surface, of this limestone-derived soil.

From rainfall to throughfall in a maritime vineyard

This study deals with the characteristics of throughfall produced by vine (Vitis vinifera L.) in one of the most common pedoclimatic conditions for grape production: a soil derived from marine sediments under a temperate Mediterranean climate, and located rather close to the seacoast. To distinguish the contribution of the plant from that of the atmospheric deposition, the throughfall was collected for more than one year under real and artificial (plastic) vines; for the same period, also the bulk precipitation was collected. The solution collected were analysed for pH, electrical conductivity, and concentration of cations and anions. For each event, the ionic fluxes of bulk precipitation and throughfall were calculated. Results indicated that the chemical composition of the bulk precipitation was strongly influenced by the proximity of the seashore and, to a lesser extent, by local anthropic activities and windblown material coming from distant areas. The chemical composition of the throughfall was affected by the same factors of bulk precipitation, but also by solubilisation of dry deposition trapped by the canopies, agronomic practices, plant, and living-on-the-leaves microorganisms. The comparison of the characteristics of the throughfall of the real with the artificial vines revealed that the vines are a source of Mg and K. During winter season, the reduction of Ca, NH(4) and PO(4) from bulk precipitation to throughfall was ascribed to the formation of biogenic minerals on the plant surface. The presence of these minerals was proved by X-ray diffraction on the powders collected during the winter season on the surface of cordons and fruiting canes. We conclude that an approach to the estimation of the nutritional potentiality of the soil that includes the contribution of the throughfall is functional to the management of the agro-ecosystem.

Data on soil physicochemical properties and chemical composition of rainfall and of throughfall and stemflow generated by Turkey oak trees (Quercus cerris L.) in acid and sub-alkaline soils

We report data on the physicochemical properties of soils collected in two adjacent areas, one acid and one sub-alkaline, both developed on sequential beds of Plio-pleistocene marine sediments, and on the chemical composition of ecological solutions (rainfall, throughfall and stemflow) separately collected in the two areas. Throughfall and stemflow were generated by Turkey oak trees (Quercus cerris L.), which was the dominant tree species in both study areas. These data are related to the original article “Soil affects throughfall and stemflow under Turkey oak (Quercus cerris L.)” (Corti et al., 2019) [1].

Effect of snowpack management on grassland biodiversity and soil properties at a ski resort in the Mediterranean basin (central Italy)

Abstract In the Mediterranean basin, the activity of ski resorts below 2000 m of altitude strongly affects grassland ecosystems because of the increasing use of artificial snow (AS). In a representative ski resort of central Apennines (Italy), we studied soil, vegetation and topographic variables of three adjacent grasslands: undisturbed grassland (UG), ski-runs with natural snow and ski-runs with amassed and AS. The winter temperature at the soil surface was colder in the ski-runs (even more in AS) than in the UG with an increase in dissolved organic matter and a biomass decrease. We identified 21 diagnostic species and 14 functional bioindicators linked to soil indicators like surface temperature and moisture. Conversely to observations made in the Alps and in other sites of the Apennines, we did not record any significant decrease in the floristic diversity between ski-runs and UG. Ski-run management aimed to prolong the snowpack duration-induced higher soil humidity and a short vegetative growth that produced a significant shift of the natural structure and composition of the grassland. To preserve key habitats for biodiversity, the construction and extension of ski resorts below the altitude of 2000 m should be avoided in the climatic belt of the Apennines.

Assessment of potential nutrient release from phosphate rock and dolostone for application in acid soils

Abstract Finding alternative local sources of plant nutrients is a practical, low-cost, and long-term strategy. In this study, laboratory column experiments were conducted in a completely randomized design to evaluate the feasibility of using phosphate rock and dolostone as fertilizers or acid-neutralizing agents for application in tropical acid soils. The dissolution rates of different particle-size fractions (0.063–0.25, 0.25–0.5, and 0.5–2 mm) of both rocks were studied by citric acid solution at pH 4 and 2 and water, with extraction times of 1, 3, 5, 7, 12, 24, 72, 144, 240, and 360 h. The results showed that the dissolution of both rocks depended on the particle size, leaching solution, and extraction time. The dissolution rate of rock-forming minerals increased as the specific surface area increased, corresponding to a decrease in particle size. In all cases, the release kinetics was characterized by two phases: 1) a first stage of rapid release that lasted 24 h and would ensure short-term nutrient release, and 2) a second stage of slow release after 24 h, representing the long-term nutrient release efficiency. Both rocks were suitable as slow-release fertilizers in strongly acid soils and would ensure the replenishment of P, Ca, and Mg. A combination of fine and medium particle-size fractions should be used to ensure high nutrient-release efficiency. Much work could remain to determine the overall impact of considerable amounts of fresh rocks in soils.