Copper (Cu) is among the main contaminant of agricultural soil. The reclamation of Cu polluted soils can be achieved with phytoextraction even if, in general, plants are Cu-excluders and uncommon are Cu-accumulators. The research objectives were to establish the Cu removal capacity by arable and vegetable crops and to investigate the distribution of Cu in their roots, stems and leaves, and fruits. Pot trials were conducted for two subsequent years in Tuscany (Italy). Cu was added into soil in four levels (0, 200, 400, 600 mg kg-1 of Cu). At harvesting, the crops roots, stems and leaves, and fruits or seeds were separately collected, oven dried, weighted, milled and separately analyzed. The results show that the GDUs value to reach the physiological maturity for barley, common bean, Indian mustard, and ricinus was significantly positively correlated with Cu concentration in soil in contrast with observed in sorghum, spinach, and tomato. Leaves and stems of spinach and ricinus have a good storage capacity in contrast with common bean, tomato, Indian mustard sorghum and barley. Tomato storage Cu mainly in fruits and roots which show a remarkable concentration of Cu that increases progressively with the increase of Cu concentration in the soil. In addition, the roots of common bean and ricinus showed a very high concentration of Cu. All species can be considered Cu-excluders because of their low capacity to uptake high quantity of Cu. Indian mustard can be considered a plant able to translocate the metal from root to epigeal tissue.

Lead (Pb) contamination risks to crops grown in urban and peri-urban soils is a great concern that should be better evaluated to define the Pb maximum levels in soils for safe cultivation and to identify suitable strategies to remediate Pb polluted urban soils. The objective of this work was to evaluate the potential risk for human health from the ingestion of the edible portions of barley, castor bean, common bean, Indian mustard, sorghum, spinach, and tomato grown in an unpolluted soil (initial Pb content 32.6 mg kg⁻¹) spiked with 0, 300, 650, 1000 mg Pb kg⁻¹, respectively. The potential possibility of using these plants to phyto-remediate the soil of Pb was also assessed. Pot trials were conducted for two years (2008 and 2009). Results highlighted that all the investigated species were able to attain growth to maturity in high Pb spiked soil, although Pb influenced dry matter accumulation. Even in soils with low Pb concentrations, Pb accumulated the edible parts. Noteworthy, even in untreated control soils, all tested species revealed a Pb concentration in the edible parts that was higher than the safe limit set by FAO/WHO. None of the investigated species were considered Pb hyperaccumulators, but all were shown to be potentially suitable for phyto-stabilization.

It is essential to investigate to which extent and how specifically soil–plant–microbe interactions can be conditioned by different agricultural practices. Legumes such as Vicia faba is one of the essential functional group in intercropping and crop rotations due to its higher N fixing capacity. Hence, it is important to study the living microbial community of this legume. Further, it is also expected that fluctuations in soil microbial diversity and composition could be complemented by plant phenological stages and different fertilizer amendments. Thus, we investigated bacterial community composition in soil treated with phosphate-based inorganic and organic fertilizers, in the presence of Vicia faba plants at flowering and fruiting time using NGS 16S rRNA gene amplicon sequencing. Further, the evaluation of plant biomass parameters under different fertilizer treatments was also carried out. The presence of the Vicia faba plant increased the abundance of N fixing bacterial such as Bardyrhizobium, Microvirga (Rhizobiales), Arthrobacter, and Psuedoarthrobacter (Actinomycetales) in soil. Fluctuation in composition and diversity of bacterial community was further supplemented by plant phenological stages. These alterations could be due to changes that occurred in the plant nutrient requirement and varied root exudation patterns at a specific phenological stage. Further, fertilizer treatments also have a profound effect on the diversity and structure of the bacterial community. Organic fertilizers, especially vegetable tanned leather waste (VTLW), have a stronger effect on the composition and diversity of bacterial community compared to inorganic fertilizer (PT—triple superphosphate). Alpha-diversity was significantly decreased by both organic and inorganic amendments, especially a species evenness because each fertilizer tends to stimulate the growth of distinctive microbes that dominated the community of amended soil. Proteobacteria, Actinobacteria, and Cyanobacteria were the most abundant phyla, and Chelatococcus, Cyanobacteria, Sphingomonas, and Microvirga were a most abundant genus that contributed most in co-occurrence pattern, which suggests that these generalists are adapted to a variety of environments. These indicate that plant presence was a key, dominating factor, followed by fertilizers and time, in affecting soil bacterial diversity and composition. Plant recruits system (fertilization and time) -specific taxa due to differences in available nutrients and energy sources among different treatments during different growth stages. Further, fertilizer treatments did not have a stronger effect on plant production as compared to the effect on microbial community, which highlights that organic fertilizers did not tend to increase plant production. Thus, organic and inorganic amendments with matched macronutrients could have a similar impact on crop yields.

Prickly pear (Opuntia ficus-indica (L.) Mill. 1768) is cultivated in several dry and semi-dry areas of the world to produce fresh fruit, bioenergy, cosmetics, medicine, and forage. One of the main production constraints is the presence of many seeds within the fruit, which can negatively influence both the fresh-fruit market price and industrial transformation processes. In this study, different gibberellic acid (GA₃) concentrations were tested for their ability to produce well-formed and seedless fruits. Different application methods (injection and spraying) and concentrations of GA₃ (0, 100, 200, 250, and 500 ppm) combined with floral-bud emasculation were applied to a commercial plantation in southern Italy to evaluate their effects on the weight, length, and diameter of the fruits, total seed number, hard-coated viable seed number, and seed weight per fruit. The results indicated that the application of 500 ppm GA₃ sprayed on emasculated floral buds was the most effective method for reducing seed numbers of prickly pear fruits (−46.0%). The injection method resulted in a very low number of seeds (−50.7%) but produced unmarketable fruit. Observed trends suggest the need to investigate the impact of higher GA₃ concentrations and the applicability of a maximum threshold. Further studies are needed to increase our understanding of the physiological effects of the gibberellic acid pathway through productive tissue in terms of organoleptic and fruit quality.