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Abstract: Chemical analyses of the phosphorus (P), carbon (C) and nitrogen (N) content of the soil were applied to an Iron age building located at Rotzo in the Asiago plateau (northeastern Italy). The building was already interpreted as a dwelling with two distinct phases of life. Both total P by ignition and organic P distributions were high in the northeast zone and along the southern wall, where there was an accumulation of organic matter because of the presence of a garbage hole. The clustering of highest inorganic P values along the eastern wall highlighted, for the first phase of life of the building, the contrast between domestic activities in the eastern and western areas, as the highest values of the C:N ratio indicate the accumulation of organic matter. The organic C content and C:N ratio, together with the different forms of P, provided good suggestions about the use of the inner space. In particular, among the P forms, oxalate extractable-P indicated the oldest phase of the house. [Copyright &y& Elsevier]

Abstract: Analyses of the phosphorus (P), carbon (C) and nitrogen (N) content of the soil, together with elemental ratios, were applied to the archaeological area of Cà Tron (Venice, Italy), where Roman farms exploited the countryside from the 1st to the 5th century BP. Two different methods, ignition (i) and hydrolysis with perchloric acid (h) were used to determine the total P (TP) content, and their reliability is discussed. Results showed very high values in both iTP and hTP in the site. High inorganic P (IP) contents were found along the walls of the building, giving evidence for the mineralization of organic P (OP) which was entrapped into inorganic with the calcium carbonate and thus preserved. Among the elemental ratios, the organic C/total C (OC/TC) and C/N highlighted organic matter from animal and not from vegetable origin, whereas the OC/OP and N/OP confirmed the anthropogenic origin of the site. All these results strongly support for the identification of the remains of a Roman rural building as a stable for bred cattle. [Copyright &y& Elsevier]

Abstract: In areas of intensive agriculture continuous applications of mineral and organic fertilizers can lead to an accumulation of phosphorus (P) in the soils and progressive saturation of their sorption capacities, increasing the risk of P losses to aquatic ecosystems. The long-term evolution (44years) of soil P forms has been studied in a factorial experiment combining three soils (sandy, clay and a peaty) with three types of fertilization (no fertilizer, farmyard manure and mineral fertilizer). The P distribution in the calcium P (PCa), iron P (PFe), iron+aluminium P (PFe+Al) forms, and the effect of treatments on P availability (oxalate extractable-P, Mehlich-3-P, Olsen-P, water extractable-P) were determined. Two sorption P indices and the degree of soil saturation were also calculated. Soil P forms were affected by both quantity and quality of P inputs. Farmyard manure caused a more consistent increase in soil P content, affecting the water soluble and labile P forms (Mehlich-3-P and Olsen-P) in particular. Readily assimilable and potentially mobile P forms were positively correlated with the amount of high molecular weight humic fractions, thus stressing the importance of the type of incorporated materials and their evolution in determining soil P behaviour. Soils treated with farmyard manure, and to a lesser extent with mineral fertilizer, exceeded the threshold values of 20mgkg−1 for Olsen-P and 150mgkg−1 for Mehlich-3-P, thus evidencing a potential risk of P loss to water bodies. While in absolute terms the more consistent accumulations were observed in clay and peaty soils, the P content of sandy soils is of particular concern, given their lower P sorption capacity and higher degree of saturation. Among the soil P tests, Mehlich-3-P proved to be the best indicator to assess Italian soil conditions for both agronomic and environmental purposes. [Copyright &y& Elsevier]

To counteract the loss of organic matter of agricultural soils, the use of compost from green and woody residues is a promising strategy. In this study, an organic farm (NE Italy) was investigated to determine the effect of management practices on physical and chemical soil properties. The organic system received three years ago a single high dose (60 t ha−1) of a wood-based compost (WBC), and it was compared with a conventional farm that annually managed mineral plus manure fertilization. In both systems, soil samples from a vineyard and field-scale rotation were collected, together with soil samples from an area not cultivated and not treated neither with compost nor with fertilizers or manure (untreated = control). Soil samples were characterized for soil fertility parameters, extractable fractions of macro- and micronutrients with DTPA and Mehlich3, and their total content. WBC was physically, chemically, and biologically characterized. The results showed that WBC fulfilled the requirements prescribed by Italian legislation, and the absence of phytotoxicity and conversely a stimulating activity towards root development was evidenced. From the DNA metabarcoding of the bacterial community, WBC revealed several peculiarities, including the dominance of taxa such as the order Acidimicrobiales, the families Anerolineaceae, Cytophagaceae, Caldimicrobiacese, Saprospiraceae and the archaeon Candidatus Nitrososphaera. Concerning the fertility of soils, the addition of WBC in both the vineyard and field-scale considerably affected some important soil parameters compared to those of conventional fertilization and untreated soil. Among these, WBC strongly increased the organic C content and the amount of the available P. In addition, the concentrations of macro- and micronutrients extractable by DTPA were generally higher with WBC than conventional fertilization. On the contrary, Mehlich3 extractable metals and total metals content were not affected by fertilization. The principal component analysis indicated that organic C, macronutrients (CaDTPA, KDTPA, and POlsen), as well as micronutrients (BDTPA, FeDTPA, and MoDTPA) are principal factors that properly separated conventional fertilization from organic fertilization. Beside this, within the same management, cases by agroecosystem were also well revealed by cluster analysis. In essence, in the short-term, the organic system led to a significant improvement in organic C and plant-available nutrients over the conventional system. [ABSTRACT FROM AUTHOR]

Concentrations of aliphatic acids, phenolic acid, and inorganic nutrients, as well as hormone-like activity, were determined in soil dissolved organic matter (DOM) from two forest sites in N Italy showing differing degrees of silver fir regeneration. In the site where silver fir recruitment was abundant, humification processes prevailed, and the soil DOM had a high content in aliphatic and phenolic acids. This enhanced the hormone-like activity in the soil, which could in turn promote growth of silver fir seedlings. In the site with poor fir recruitment, the soil DOM underwent rapid mineralization and was richer in inorganic nutrients, but had lower concentrations of aliphatic and phenolic acids, and lower hormone-like activity.