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Simple Summary Agroforestry is a practice, which consists of having orchard, crops and animals in the same land. This system shows many sustainability advantages like reductions of land use, permitting to obtain two productions (vegetal and animal) in the same area. Moreover, if the animals are well managed, they exert a double action by fertilizing and weeding the soil. The agroforestry system here studied consists of an organic vineyard where geese at two densities (High Geese Density-HGD and Low Geese Density-LGD) were reared. In the organic vineyard, only Copper (Cu) treatment is allowed, like antifungal. The aim was to investigate the chemical and biochemical properties of the soil with geese and the impact of Cu on the soil and animal tissues. The main results showed that the presence of animals improves the efficiency of the microbial biomass mainly in the upper soil horizons. Moreover, the grazing activity of geese removes Cu from the soil with the grass intake and showed a moderate accumulation in the liver. However, no significant difference was present in the edible tissues (breast and drumstick) of the vineyard geese in respect to the control ones. Abstract Agroforestry systems aim at increasing the productivity and the environmental sustainability of both crop and animal productions. The integration of small animals such as geese in the vineyard could represent an opportunity to improve farm income and reduce land use for grazing. The main objective of this work was to study the impact of geese rearing in an organic vineyard on the chemical and biochemical properties of the soil and the effect of Copper (Cu) supplied with the fungicide treatments. Furthermore, the amount of Cu in the animal tissues was also investigated. Three experimental areas within the vineyard were selected: High Geese Density (HGD-240 geese ha−1), Low Geese Density (LGD-120 geese ha−1) and Without Geese used as control soil (WG). The results indicated that both HGD and LGD did not affect the main chemical properties of the vineyard soils. LGD increased the amount and the efficiency of the microbial biomass in the upper soil horizons. Moreover, geese through the grazing activity reduced the Cu content in the vineyard soils, accumulating this element in their liver. However, the content of Cu in the breast and drumstick of vineyard geese did not show any significant difference in respect the meat of the control ones.

Soil magnetic properties are sensitive indicators of pedogenetic processes. Although many of the processes that increase soil magnetism are well documented, the role of microbial communities and the metabolic characteristics of Fe-reducing bacteria are still largely unknown. For this work, two soils with contrasting magnetic properties were identified in a beech forest on Monte Zuccarello (central Italy). Samples of bulk soil and rhizosphere were obtained from A (0–7 cm), AB (7–16 cm), Bw1 (16–22 cm) and Bw2 (22–29 cm) horizons of both soils, and were analysed for their physicochemical characteristics, the amount of magnetic minerals, and the composition of total and culturable bacterial communities, focusing on siderophore-producing bacteria (SPB). Analyses confirmed that the magnetic soil (MS) have a higher content of maghemite and magnetite association, compared to non-magnetic soil (NMS). Since the formation of maghemite can occur through different processes, we investigated on the possible role of soil bacteria in the formation of this magnetic mineral. As soil maghemite generally contains small amounts of Fe2+, the formation of which has been attributed to the combustion of organic matter, SPB have been isolated and identified. MS samples showed the highest number of SPB (mainly Micrococcaceae, Bacillaceae, and Pseudomonadaceae), suggesting a significant increase in Fe-reducing bacteria. High-throughput sequencing analysis revealed a separation in terms of the total composition of the bacterial community between bulk and rhizosphere of both MS and NMS, dominated by Proteobacteria, Actinobacteria, Acidobacteria, and Verrucomicrobia phyla. Interestingly, Gamma and Delta Proteobacteria, as well as Nitrospirae, were usually more abundant in MS than in NMS, confirming that the MS was predominantly characterized by groups of magnetotactic bacteria and SPB, and potentially contributing to enhance the soil magnetic properties.

This study evaluated soil properties along a small transect in the Apennines chain (central Italy). Using latitude and altitude as surrogates for temperature differences, three locations at different latitudes were selected for the study. At each location, two altitudes were selected (800 and 1000 m). The study was conducted by contrasting chemical and biochemical parameters [microbial biomass-C content, amount of CO2 evolved during basal respiration (ΣCO2–C), and potential enzyme activities] of topsoils (O and A horizons) supporting European beech (Fagus sylvatica L.) forests at different scales of investigation: horizons, altitude, and latitude. Along the topsoil, the trend of all investigated properties was unique to each O and A horizon according to its level of organic matter degradation, availability of substrates, and nutrients. Contrasting the altitudes, the difference of 1 °C of temperature between 800 and 1000 m significantly affected some of the chemical parameters and both microbial and enzyme activities mainly in the mineral horizons, although glucuronidase and phosphodiesterase activities appeared to be mainly controlled by TOC content. Generally, the different enzyme activities were more clearly highlighted when they were expressed per organic C unit, rather than on a soil mass basis. Latitudinal sensitivity was recorded for total N, ΣCO2–C, and some enzyme activities, although no difference in mean annual air temperature occurred along the latitudinal transect. In this case, it is plausible that the summer-winter thermal excursion, which was lower for the southernmost location and increased going north, might have indirectly affected these parameters through changes in the plant-soil relationships, composition of the macro- and mesofauna population, and microbial activity. Considering all the investigated aspects, an increase of 1 °C in mean annual air temperature (in the range 9–10 °C) and/or the alteration of summer-winter thermal excursion might affect the actual soil-plant balance in temperate beech forests, with possible greater mineralization of the topsoil organic matter and a major release of CO2 in the atmosphere.

Water-extractable organic matter (WEOM) is the most dynamic and bioavailable fraction of the soil organic matter pool. Although the litter floor is considered the main source of WEOM, roots also release a great amount of labile organic compounds through rhizodeposition processes. This makes the rhizosphere, the small soil volume in proximity to the roots, a soil compartment relatively enriched in WEOM. Since both the rhizosphere and the labile organic C pool are highly sensitive to the environmental conditions we evaluated the characteristics of WEOM from rhizosphere and bulk soil collected from the A horizons of European beech (Fagus sylvatica L.) forest soils of Apennines mountains (central Italy) at two altitudes (800 and 1000 m), using elevation as a proxy for temperature change. Specifically, we tested if i) the rhizosphere contains higher amounts of WEOM with a greater diversity of compounds with respect to the bulk soil, and ii) this effect is more pronounced at higher altitude. At both 800 m and 1000 m above sea level, the main distinction between WEOM from rhizosphere and bulk soil was the larger amounts of sugars in the soil close to the roots. Further, our results indicated an influence of altitude on rhizospheric processes as suggested by the larger concentrations of organic C and soluble phenols, and richness of tannins in the rhizosphere WEOM than in the bulk soil at 1000 m. We attributed this influence to environmental constraints which enhanced the release of labile organics and secondary metabolites by rhizodeposition and humification processes in the rhizosphere. As a whole, our data draw a picture where the roots are able to affect the characteristics of WEOM and environmental constraints enhance the differentiation between rhizosphere and bulk soil. This view confirms the influence of the rhizosphere on the soil C cycle, and the importance of the rhizospheric processes when environmental conditions become harsher.

Phosphorus (P) is an important nutrient for plant growth but its availability in soil is limited. Although plants are able to respond to the P shortage, climatic factors might modify the soil-plant-microorganisms system and reduce P availability. In this study we evaluated the rhizosphere effect of beech (Fagus sylvatica L.) in forest soils of Apennines mountains (central Italy) at two altitudes (800 and 1000 m) and along 1° of latitudinal gradient, using latitude and altitude as proxies for temperature change. Specifically, we tested if 1) soil organic C, total N, and organic and available P decrease with increasing latitude and altitude, and 2) the rhizosphere effect on P availability becomes more pronounced when potential nutrient limitations are more severe, as it happens with increasing latitude and altitude. The results showed that the small latitudinal gradient has no effect on soil properties. Conversely, significant changes occurred between 800 and 1000 m above sea level, as the soils at higher altitude showed greater total organic C (TOC) content, organic and available P contents, and alkaline mono-phosphatases activity than the soils at lower altitude. Further, at the higher altitude, a marked rhizosphere effect was detected, as indicated by greater concentration of TOC, water extractable organic C, and available P, and its fulfillment was mainly attributed to the release of labile organics through rhizodeposition. The availability of easy degradable compounds in the rhizosphere should foster the mineralization of the organic matter with a consequent increase of available P. Hence, we speculate that at high altitude the energy supplied by the plants through rhizodeposition to the rhizosphere heterotrophic microbial community is key for fuelling the rhizospheric processes and, in particular, P cycling.

Background and Aims - The 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. Methods - Bulk and rhizosphere soils were characterized by physical, mineralogical, chemical and biological (microbial activity and community structure) analyses. Results - Throughout 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). Conclusions - The 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.

Climate warming is predicted to raise the mean global temperature by 1 °C in the next 50 years, and this change is believed to be capable of affecting soil organic matter cycling and nutrient availability. With the aim of increasing knowledge on the response of forest soils to the ongoing climate change, we used altitude as a proxy for temperature change and studied chemical and biochemical properties of European beech (Fagus sylvatica L.) forest soils at two altitudes (800 and 1000 m) from central Apennines (Italy). Results showed that 1 °C of mean annual air temperature difference between the sites at the two altitudes had greater effect on the mineral horizons than on the organic horizons. At higher altitude, mineral soil had limited development, higher pH, and higher organic matter content due to the lower efficiency of the microbial community. Enzymatic activities of the organic horizons were generally not affected by altitude. Conversely, we observed a higher activity of xylosidase, β-glucosidase, alkaline phosphomonoesterase, arylsulfatase, and leucine-aminopeptidase in the sub-superficial horizons (Bw1 and Bw2) of the soils at 1000 m. We hypothesized that, as a response to environmental and climatic constraints occurring at higher altitude, plant roots increase the production of enzymes directly and/or indirectly by triggering the microbial community through exudation.