Vegetable and ornamental crops require high input demand to adequately support their standard commercial quality and yield. For these crops, a very high level of agronomic use efficiency of many productive factors can be achieved in soilless culture. For example, the benefits derived from the adoption of soilless closed loops for the recirculation of the nutrient solution are well known as a benchmark of excellence for nutrient and water use efficiency. The challenges that we now face are as follows: (i) making soilless systems more inclusive of sustainable and eco-friendly growing substrates, possibly available at a local level; (ii) replacing chemicals with more sustainable products (e.g., organic active compounds) as much as possible for plant nutrition and protection. These goals can be addressed by following different approaches, but the adoption of peat-free organic substrates may play a central role. This work investigates four organic materials, i.e., biochar, coir, green compost, and wood fibers, to assess their role in plant nutrition and protection when used as components for the preparation of growing media in the soilless cultivation of containerized crops. In further detail, the work highlights how these materials may support normal agronomic practices.

The use of fertigation, coupled with micro-irrigation, has continued to increase since it was first introduced in horticultural cropping systems. This combination provides a technical solution whereby nutrients and water can be supplied to the crop with high precision in terms of time and space, thereby allowing high nutrient use efficiency. However, the correct estimation of crop nutrient and water needs is fundamental to obtaining precise plant nutrition and high nutrient use efficiency in fertigated cropping systems. This paper illustrates the state-of-the-art and new perspectives for optimal nutrient management of vegetable crops cultivated under fertigation regimes. An overall description is reported for the most valuable technologies and techniques based on simulation models, soil testing, plant testing, and related decision support systems that can be adopted for efficient fertigation. However, it should be highlighted that only a few of the above technologies and techniques are practically available and/or easy to use by growers. Therefore, much more attention should be paid in the future to the transfer of research knowledge to farmers and technical advisors.

In many irrigated areas of the Mediterranean region, farmers are forced to use saline water to irrigate their crops due to an inadequate supply of fresh water. Grafting may represent an effective tool to improve crop tolerance to salinity. Two greenhouse experiments were carried out to determine yield, fruit quality and mineral composition of melon plants (Cucumis melo L. cv. ‘Cyrano’), either ungrafted or grafted onto the commercial rootstock ‘P360’ (Cucurbita maxima C. moschata) and cultured in pumice. Plants were supplied with nutrient solutions having electrical conductivities (EC) of 2.0, 4.0, 5.9, 7.8 or 9.7 dS m^–1. The saline nutrient solutions (those > 2.0 dS m^–1) had the same basic composition, plus an additional 20, 40, 60 or 80 mM NaCl, respectively. In both years (2003 and 2004), increased salinity in the nutrient solution resulted in a linear decrease in marketable yield compared to controls that was due to reductions in the size and number of marketable fruits. Averaged across years and nutrient solution concentrations, marketable fruit yield was 44% higher in grafted than in ungrafted plants. The lowest marketable yield recorded in ungrafted plants was associated with a reduction in both mean fruit weight and in the number of fruits per plant compared to grafted plants. Salinity improved fruit quality in both grafting combinations by increasing firmness, dry matter (DM), acidity and total soluble solids (TSS) contents. The nutritional qualities of grafted melons such as fruit DM, titratable acidity and TSS content were slightly inferior compared to those of ungrafted plants, whereas physical qualities such as fruit firmness and Hunter colour values (L* and a*/b*) were superior compared to those of plants grown with their own roots. Grafted plants could reduce leaf Na⁺ ion, but not Cl^– ion, concentrations. However, the sensitivity to salinity was similar between grafted and ungrafted plants, and the higher marketable yield from grafted plants was mainly due to grafting per se.

Increasing the ability to investigate plant functions and structure through non-invasive methods with high accuracy has become a major target in plant breeding and precision agriculture. Emerging approaches in plant phenotyping play a key role in unraveling quantitative traits responsible for growth, production, quality, and resistance to various stresses. Beyond fully automatic phenotyping systems, several promising technologies can help accurately characterize a wide range of plant traits at affordable costs and with high-throughput. In this review, we revisit the principles of proximal and remote sensing, describing the application of non-invasive devices for precision phenotyping applied to the protected horticulture. Potentiality and constraints of big data management and integration with “omics” disciplines will also be discussed.