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.
Biochar, an important by-product of the waste biomass pyrolysis process, shows great potential to reduce the environmental impact of and address the serious problems related to climate change as well as to define an efficient circular economy model. Its use as a soil conditioner has increased the interest in biochar in agriculture over time. This review investigates how critical aspects such as starting material, temperature, and the presence or absence of oxygen during the pyrolysis process influence the yield and quality of this valuable soil conditioner. Considering the horticultural sector, this review also provides a comprehensive and detailed overview of how biochar positively influences growth, development, and yield by explaining the mechanisms and modes of action under both optimal growth conditions and unfavorable contexts (salt and water stress and the presence of heavy metals). The main mechanisms highlighted by this literature review are improvement in soil aeration and water-holding capacity, microbial activity, and nutritional status of soil and plants, as well as alterations in some important soil chemical properties. This in-depth review of the literature highlights how the interaction between biochar types, dose, crop species, and growing conditions (optimal or nonoptimal) result in nonunique responses. The heterogeneity of the results reported in the literature confirms how many of the topics discussed deserve further investigation, with particular attention to identifying the right dose of biochar in relation to the different preharvest factors considered.
The increase in the frequency and magnitude of environmental stresses poses a significant risk to the stability of food supplies. In coastal areas of the Mediterranean, brackish water has long been considered a limitation on horticultural production. In this scenario, the use of biochar in agriculture could be considered a valuable tool to cope with the deleterious effects of salt stress. This work aimed to investigate, in a protected environment, the effects of different concentrations of biochar (0, 1, and 2% v/v) obtained from poplar (Populus L.) biomass on the yield and quality of dwarf San Marzano ecotype tomatoes irrigated with saline water at different concentrations of NaCl (0, 40 and 80 mM). The increase in salt concentration from 0 to 80 mM NaCl reduced the total yield (−63%) and the number of fruits (−25%), but improved the main quality parameters such as dry matter (+75%), total soluble solids (+56%), and polyphenol content (+43%). Compared to control conditions, biochar supplementation improved the total yield (+23%) and number of fruits (+26%) without altering the functional and organoleptic characteristics of the fruits. The promising results underscore the potential of biochar as a sustainable solution to amend soils in order to improve tomato production under unfavorable conditions such as high salinity. However, there is a need to clarify which adaptation mechanisms triggered by biochar amending improve production responses even and especially under suboptimal growing conditions.
Thanks to its numerous uses in gastronomy, pharmaceuticals, and cosmetics, basil (Ocimum spp.) is one of the most studied and consumed aromatic plants worldwide. However, its commercialization and availability are limited by its short post-harvest shelf-life, primarily due to its strong sensitivity to cold, poor handling, and consequent microbial contamination. This review provides a comprehensive overview of the latest research on pre-harvest techniques that can extend the shelf-life of basil, aiming to offer a practical tool for growers, distributors, retailers, and scientists. In addition to influencing the plant’s primary metabolism, pre-harvest factors, such as genotype selection, plant nutrition, irrigation, and light management, can have a direct impact on basil quality and shelf-life. Unlike previous reviews, which primarily focus on post-harvest strategies, this work provides a structured analysis of pre-harvest factors that directly influence basil’s shelf-life. By integrating recent findings on genotype selection, nutrient management, and environmental conditions, we offer a comprehensive framework to guide future agronomic practices aimed at minimizing post-harvest losses and enhancing product quality.