Chiara Cassinari

Purpose Floods are considered the major threat of soil suitability loss for agricultural purposes in floodplain agroecosystems. The present work questioned (i) how does the flooding affect soil of agricultural lands? (ii) can the mixing of deposited sediments with the covered soil be considered a suitable practice to keep soil functionality? Materials and methods The study was conducted in three croplands of Emilia–Romagna region affected by floodings in May 2023. The sampling concerned both the deposited sediments and the covered soil, then mixtures of deposited sediment and covered soil at 1:1 ratio (soil–sed) were also obtained. These samples were analysed for the main physicochemical properties, the water infiltration and the crusting index. Results and discussion The deposited sediments had a lower amount of nitrogen (-47%), organic C (-47%) and available phosphorus (-60%), and a higher silt content (+ 17%) compared to the covered soil. The obtained soil–sed had a lower amount of such nutrients than covered soil. Further, the higher silt content in soil–sed than in covered soil does not help the accumulation of such nutrients and lowered the water infiltration. The soil–sed had a higher crusting index (+ 24%) compared to the covered soil suggesting a higher probability of soil to promote surface runoff. Conclusions In the investigated study sites, the flooding had a marked effect on soil physical properties because of the higher silt content and the lower organic carbon content of deposited sediments compared to covered soil. To face such issues for allowing agricultural productivity, the addition of organic amendments can be suggested due their cost–effectiveness.

Soil degradation is characterized by the reduction of soil thickness and fertility. Reconstitution technique was used to reclaim the degraded soil covering a closed landfill and to restore the fertility of farm soils in Northern Italy (Piacenza province , Emilia-Romagna region). Reconstitution applied chemical and mechanical actions to degraded soils and/or alluvial sediments mixed with waste from different productive processes. The aim of this study was to describe how reconstitution changed the phys-icochemical properties of the original soils used in the mixture. The results show that reconstitution produced soils with improved physical properties; on average, in reconstituted soils bulk density was 45% and particle density was 10% lower than original soils. The same was observed for the chemical properties; on average, in reconstituted soils pH was 5% lower than original ones, whereas organic C was 82% and N was 59% higher.

A reconstituted soil, derived from mechanical and chemical treatments of a Technosol mixed with organic matrices, was evaluated as a suitable soil for tomato growth. The physico-chemical properties of the reconstituted and original soils were analysed, and SPAD readings and plant height related to the phenological stages, as well as yield of the whole plant and fruits at maturity were also measured. Reconstitution increased soil porosity, water holding capacity, organic carbon and total nitrogen. Plants grown in the reconstituted soil had a statistically higher height at 16 and 35 days after transplanting. Leaf SPAD value at the emergence of inflorescence was also greater than that measured in the original soil. Shoot and root fresh/dry weights, and number and weight of red fruits were also higher under the reconstituted soil. The results indicate that with the reconstitution technique positive effects can be expected on the improvement of soil degradation and fertility, resulting in better tomato yield.

Summary: Reconstitution is a pedotechnique to counter land degradation and desertification. The reconstitution, patented by the research laboratory m.c.m. Ecosistemi, applies chemical-mechanical actions to a mixture of degraded soil and matrices (such as waste sludge) in order to produce reconstituted soil, a very high fertility soil. This paper is about a pot study in a greenhouse to investigate how reconstituted soil affects emergence speed and seminal roots development of Zea mays L. seedlings, in comparison with a Technosol. 200 seedlings are monitored up to the 16^th day after the seeding. The emergence percentage is 98% on reconstituted soil and 91% on Technosol. Average length and weight of fresh seminal roots are higher on reconstituted soil.

In this paper the results of a study of soil hydraulic properties and plant coverage of a landfill located in Piacenza (Po Valley, Italy) are presented, together with the attempt to relate the hydraulic properties in relation with plant coverage. The measured soil water retention curve was first compared with the output of pedotransfer functions taken from the literature and then compared with the output of the same pedotransfer functions applied to a reference soil. The landfill plant coverage was also studied. The relationship between soil hydraulic properties and plant coverage showed that the landfill soils have a low water content available for plants. The soils' low water content, together with a lack of depth and a compacted structure, justifies the presence of a nitrophilous, disturbed-soil vegetation type, dominated by ephemeral annual species (therophytes).

In this paper the results of a study of soil hydraulic properties and plant coverage of a landfill located in Piacenza (Po Valley, Italy) are presented, together with the attempt to put the hydraulic properties in relation with plant coverage. The measured soil water retention curve was first compared with the output of some pedotransfer functions taken from the literature and then with the output of the same pedotransfer functions applied to a reference soil. The landfill plant coverage was also studied. The relation between soil hydraulic properties and plant coverage showed that the landfill soils have a low water content available for plants and this fact, together with their lack of depth and compacted structure, justifies the presence of a nitrophilous, disturbed-soil vegetation type, dominated by ephemeral annual species (therophytes).