Michele Ciriello

Scientific literature reports mixed results in terms of crop yields grown in soils amended with biochar and compost. These discrepancies are mainly attributed to the heterogeneity of waste materials used, the production processes, and the application rates. To address the challenge of reducing synthetic fertilizer inputs in the Mediterranean area, three experiments were conducted to evaluate the effect of biochar, compost, and their combination on the yield and nutrient uptake of lettuce (Experiment 1), spinach (Experiment 2), and arugula (Experiment 3) grown under three fertilization regimes (none, suboptimal, and optimal). Regardless of the fertilization level, the combination of the two soil conditioners generally exerted a positive synergistic effect on crop yield, although it increased nitrate concentration in spinach leaves (+ 31.44%) and in arugula leaves (+ 84.55% in the first cut and + 112.79% in the second cut) compared to the control conditions. While all three experiments showed a promising reduction of the production gap between plants grown under optimal conditions and those grown under no or sub-optimal fertilization, the best results were not always achieved with the combined application of compost and biochar. In experiment 2, for instance, the combination of compost and biochar exhibited an antagonistic effect on yield under sub-optimal fertilization conditions, whereas in experiment 3, a clear synergistic action was observed, with arugula yield in the first cut increasing by 16.44%. The heterogeneous results obtained across the three different experiments, both in terms of yield and nutrient uptake, highlight the need for tailored agronomic strategies that take into account the multiple interacting factors involved, including crop species.

In line with sustainability goals, biological alternatives to chemical fumigants are increasingly in demand to support intensive baby leaf lettuce cultivation systems. This study evaluated the combined effects of soil disinfestation strategies and foliar biostimulants on crop performance and nutritional quality. With the aim of evaluating the interactive effects of biofumigation and the application of Trichoderma spp., Ascophyllum nodosum extract, and vegetable protein hydrolysate, an experiment was conducted under controlled growing conditions, integrating microbial and foliar treatments on two lettuce cycles. Soil microbial load, plant biometric traits, ionic profiles, antioxidant activity, and polyphenolic compounds were quantified. Biofumigation induced a marked recovery of bacterial populations, while both soil treatments resulted in sustained fungal suppression and the absence of detectable Fusarium spp. Biofumigation consistently increased fresh and dry biomass, highlighting its dual sanitizing and fertilizing role. Foliar biostimulants, particularly vegetable protein hydrolysate, significantly enhanced dry matter accumulation, reduced nitrate concentration, and improved cation uptake. Antioxidant activity and phenolic metabolism were strongly stimulated by Trichoderma spp. and protein hydrolysate, with significant synergistic effects on key hydroxycinnamic acids and flavonoids. These findings indicate that integrating biological soil disinfestation with foliar biostimulation improves yield stability and nutritional quality, supporting a sustainable framework for high-value baby leaf lettuce production.

Soil management is crucial for addressing soil-borne pathogens, weeds, and pests, ensuring sustainable crop productivity. Traditional chemical fumigants, such as methyl bromide, have been effective but pose serious environmental risks, including ozone depletion and reduced soil biodiversity. Consequently, attention has shifted toward more sustainable alternatives. Techniques like soil solarization, anaerobic soil disinfestation (ASD), biofumigation, and the use of biological control agents (BCAs) offer environmentally friendly options for managing soil-borne diseases. Steam and microwave disinfestation are also promising techniques; however, further development is required to improve their practical efficiency. Integrated management approaches, which combine multiple interventions, have proven particularly effective, offering flexibility and enhancing control through complementary techniques. Additionally, emerging technologies such as artificial intelligence and hyperspectral imaging provide new opportunities for real-time monitoring and decision-support to optimize the timing and targeting of pest management interventions. This review emphasizes the potential of sustainable soil pest control methods to reduce reliance on chemical fumigants, improve crop yield and quality, and support environmentally responsible farming practices. It also examines the challenges associated with scalability, cost, and variable effectiveness, while outlining the strengths, weaknesses, and mechanisms of each method. Further research on regional adaptation, technological integration, and long-term impacts is essential to fully optimize these innovative solutions for food security and sustainable agriculture.

Microgreens are promising crops for low-input systems, but the roles of species traits and root environments under uncontrolled greenhouse conditions are not yet fully addressed. In this study, mibuna and pak choi were evaluated in the presence or absence of substrate to clarify how genetic and physical factors shape growth and biochemical composition. Clear species-dependent differences emerged. Pak choi showed higher constitutive levels of chlorophyll a, anthocyanins, and key osmotic ions, and these features contributed to a more hydrated tissue profile. Mibuna instead exhibited a higher dry matter content, approximately 7% compared with 5.86% in pak choi, and a lighter canopy. The use of peat markedly improved overall growth. Fresh yield increased by more than 50%, and dry yield increased by almost 48% compared with the substrate-free system. Peat also enhanced organic acid metabolism, with malate and citrate increasing by 277 and 102%, respectively. Despite such differences, nitrate concentrations remained low and within safe limits for leafy vegetables in all treatments. The results indicate that species identity and the cultivation system significantly shaped overall microgreen performance under low-input conditions. Understanding these drivers provides a foundation for optimizing production while maintaining desirable nutritional traits.

Fresh lettuce is a key ingredient in ready-to-eat salads that are considered a valued dietary choice. Lettuce quality is strongly influenced by soil management practices, particularly in sustainable farming systems. This study evaluated the effects of three different soil disinfestation methods (flame weeding, microwave irradiation, and biological control (Trichoderma spp. inoculation) on the quality traits of Lactuca sativa L. var. Margò grown in a protected environment in southern Italy in a winter growth cycle. Minerals, nitrate content, colorimetric parameters, carotenoids, polyphenols, and antioxidant activity were assessed. The treatment with Trichoderma spp. significantly reduced nitrate accumulation (−21.3%) and increased some phenolic compounds and P (22%), while microwave irradiation treatment boosted total phenolic content by 44%. Flame weeding, although partially effective, was associated with a slight increase in carotenoids. Overall, microwave irradiation and Trichoderma spp. treatments emerged as the most promising options for balancing food safety and nutritional value. These findings offer valuable insights about the effect of soil disinfestation strategies on leafy vegetable quality.

The agricultural sector is called upon to face increasingly urgent challenges related to population growth and climate change. In this context, greenhouse cultivation represents a strategic solution capable of evolving towards more sustainable models from both an economic and environmental point of view. This review takes a multidisciplinary approach to fill the gap of a comprehensive view in the literature, analyzing the main strategies to improve the efficiency of energy, water, nutrient, and CO₂ use in greenhouses. The analysis identifies key factors and barriers affecting technology choices across countries, emphasizing the significant divide between developing and advanced economies. Economic incentives and supportive policies are crucial for promoting sustainable practices. While renewable energy sources can lower Long-term energy costs, their high initial investment can Limit adoption without sufficient incentives. Additionally, soilless systems can enhance water efficiency by up to 90%, yet in many arid regions, the scarcity of fresh water necessitates the exploration of alternative sources. The recovery of nutrients from waste and CO₂ from industrial symbioses are promising circular strategies. They can potentially reduce the reliance on synthetic fertilizers by 20–50% while also lowering the costs associated with carbon fertilization. The effectiveness of these solutions hinges on operators’ awareness of the associated benefits and risks, along with their capacity to select the option that best aligns with local conditions, such as available resources, infrastructure, incentives, and expertise. Therefore, our review targets farmers, investors, researchers, and policymakers, aiming to enhance understanding of the various strategies available and how they can foster a balance between economic viability and environmental sustainability, tailored to specific contexts. Graphical Abstract

Arugula leaves (Diplotaxis tenuifolia L. and Eruca sativa L.) are a must-have ingredient in ready-to-eat salads, as they are prized for their appearance, taste, and flavor. The nutraceutical properties of this leafy vegetable are attributed to the presence of valuable secondary metabolites, such as phenolic acids and glucosinolates. Using UHPLC-Q-Orbitrap HRMS analysis and ion chromatography, we characterized the content of phenolic acids, glucosinolates, nitrates, and organic acids in organic arugula [Diplotaxis tenuifolia (L.) DC] and evaluated how the foliar application of three different non-microbial biostimulants (a seaweed extract, a vegetable protein hydrolysate, and a tropical plant extract) modulated the expression of these. Although the application of vegetable protein hydrolysate increased, compared to control plants, the nitrate content, the application of the same biostimulant increased the total content of glucosinolates and phenolic acid derivatives by 5.2 and 17.2%. Specifically, the foliar application of the plant-based biostimulant hydrolyzed protein significantly increased the content of glucoerucin (+22.9%), glucocheirolin (+76.8%), and ferulic acid (+94.1%). The highest values of flavonoid derivatives (173.03 μg g⁻¹ dw) were recorded from plants subjected to the exogenous application of seaweed extract. The results obtained underscore how biostimulants, depending on their origin and composition, can be exploited not only to improve agronomic performance but also to enhance the nutraceutical content of vegetables, guaranteeing end consumers a product with premium quality characteristics.

As part of the European Green Deal, the Farm to Fork strategy was introduced with the idea that environment, agriculture and food are interconnected topics. Reducing the use of synthetic fertilizers by 20% before 2030 through the adoption of circular economy principles is one of the goals to be achieved. There are several bioproducts that can be obtained from the valorization of agro-industrial wastes used to increase crop yields under low-fertilizer applications. However, the aim of this review is to describe production methods and the use of compost tea on horticultural crops to understand its real potential in providing plant growth support. The effects of compost tea on crops can vary widely depending on the waste material used, compost quality, compost tea production process and parameters, and the interaction between horticultural species and compost tea application dose. Therefore, because of this heterogeneity, it is possible that we would achieve real, positive impacts on the environment and horticultural production if there were more collaboration between the research sector and private farms. This collaboration would allow the development of protocols for compost tea production and customized use according to real farm needs. This would reduce both the costs associated with the disposal of waste produced on the farm and reduce the costs associated with the supply of synthetic fertilizers. The adoption of on-farm guidelines for compost tea use would achieve a balanced trade-off between agricultural productivity and environmental sustainability. The literature review shows that the most-used dilution ratios, regardless of the type of starting compost, range from 1:5 to 1:10 compost–water (v/v). Although a complete understanding of the biostimulatory mechanisms activated by compost tea is lacking, the application of this bioproduct would improve the physiological and productive performance of many horticultural species of interest, especially under suboptimal conditions such as organic production.