The global production quantity and the utilisation area harvested for the cultivation of tomatoes have significantly increased in the last three decades. Europe still plays an important role in the production of tomatoes, accounting for 12% of global production in 2020. Tomato production can be divided into greenhouse/soilless production and open field production. Greenhouse/soilless tomato production is mostly developed in northern Europe, and open field production in southern Europe. Soilless cultivation serves to improve control of the growing medium and to avoid any likely problems for watering and maintaining proper nutrient concentrations. Beneficial soil microorganisms, particularly arbuscular mycorrhizal fungi (AMF), are increasingly being recognized as key elements of an agro-ecological approach to agricultural production. The use of these beneficial microorganisms on soilless tomato production may improve plant performance and reduce biotic and abiotic stress occurring during production with a consequent decrease of chemicals and increase of sustainability of the production system. In this paper, we tested different substrates composed of coconut fiber and bagasse (S1 to S4) and beneficial microorganisms (AMF, Pseudomonas fluorescens and Trichoderma harzianum), selecting the most suitable system for the soilless production of tomatoes. Our results showed that substrates S1 (100% coconut fiber) and S2 (66% coconut fiber + 33% bagasse) complementarily used with the consortium of “AMF IP21 + Trichoderma harzianum + Pseudomonas fluorescens IPB04” seem to be the “best formulation” for this purpose. That confirmed the feasibility of the development of recycled material (coconut fiber and bagasse)-based substrates together with soil microorganisms (AMF and beneficial bacteria) for soilless tomato production.

The analysis of soil nematode communities provides information on their impact on soil quality and the health of different agricultural cropping systems and soil management practices, which is necessary to evaluate their sustainability. Here, we evaluated the status of nematode communities and trophic groups’ abundance in fifteen fields hosting different cropping systems and managed according to organic or conventional practices. The nematode population densities differed significantly across cropping systems and management types covering various European climatic zones (spanning 121 to 799 individuals per sample). Population density was affected by the duration of the cropping system, with the lowest value in the vegetable cropping system (on average about 300 individuals) and the highest in the long-term fruiting system (on average more than 500 individuals). The occurrence and abundance of the different trophic groups was partly dependent on the cropping system or the management method, particularly for the bacteria, fungal and plant feeders. The taxonomical classification of a subset of samples allowed us to identify 22 genera and one family (Dorylaimidae) within the five trophic groups. Few taxa were observed in all fields and samples (i.e., Rhabditis and Cephalobus), while Aphelenchoides or Pratylenchus were present in the majority of samples. Phosphorus content was the only soil chemical parameter showing a positive correlation with total nematode population and bacterial feeders’ absolute abundance. Based on the nematological ecological indices, all three cropping systems were characterized by disturbed soil conditions, conductive and dominated by bacterivorous nematodes. This knowledge could lead to a choice of soil management practices that sustain a transition toward healthy soils.