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).

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.