Soilless cultivation represent a valid opportunity for the agricultural production sector, especially in areas characterized by severe soil degradation and limited water availability. Furthermore, ...this agronomic practice embodies a favorable response toward an environment-friendly agriculture and a promising tool in the vision of a general challenge in terms of food security. This review aims therefore at unraveling limitations and opportunities of hydroponic solutions used in soilless cropping systems focusing on the plant mineral nutrition process. In particular, this review provides information (1) on the processes and mechanisms occurring in the hydroponic solutions that ensure an adequate nutrient concentration and thus an optimal nutrient acquisition without leading to nutritional disorders influencing ultimately also crop quality (e.g., solubilization/precipitation of nutrients/elements in the hydroponic solution, substrate specificity in the nutrient uptake process, nutrient competition/antagonism and interactions among nutrients); (2) on new emerging technologies that might improve the management of soilless cropping systems such as the use of nanoparticles and beneficial microorganism like plant growth-promoting rhizobacteria (PGPRs); (3) on tools (multi-element sensors and interpretation algorithms based on machine learning logics to analyze such data) that might be exploited in a smart agriculture approach to monitor the availability of nutrients/elements in the hydroponic solution and to modify its composition in
. These aspects are discussed considering what has been recently demonstrated at the scientific level and applied in the industrial context.
Aquaponics (AP) is a semi-closed system of food production that combines aquaculture and hydroponics and represents a new agricultural system integrating producers and consumers. The aim of this ...study was to test the effect of stocking densities (APL, 2.5 kg m-3; APH, 4.6 kg m-3) on water quality, growth performance of the European Carp (Cyprinus carpio L.), and yield of leafy vegetables (catalogna, lettuce, and Swiss Chard) in a low-technology AP pilot system compared to a hydroponic cultivation. The AP daily consumption of water due to evapotranspiration was not different among treatments with an average value of 8.2 L d-1, equal to 1.37% of the total water content of the system. Dissolved oxygen was significantly (p < 0.05) different among treatments with the lowest median value recorded with the highest stocking density of fish (5.6 mg L-1) and the highest median value in the hydroponic control (8.7 mg L-1). Marketable yield of the vegetables was significantly different among treatments with the highest production in the hydroponic control for catalogna (1.2 kg m-2) and in the APL treatment for Swiss Chard (5.3 kg m-2). The yield of lettuce did not differ significantly between hydroponic control and APL system (4.0 kg m-2 on average). The lowest production of vegetables was obtained in the APH system. The final weight (515 g vs. 413 g for APL and APH, respectively), specific growth rate (0.79% d-1 vs. 0.68% d-1), and feed conversion (1.55 vs. 1.86) of European Carp decreased when stocking density increased, whereas total yield of biomass was higher in the APH system (4.45 kg m-3 vs. 6.88 kg m-3). A low mortality (3% on average) was observed in both AP treatments. Overall, the results showed that a low initial stocking density at 2.5 kg m-3 improved the production of European Carp and of leafy vegetables by maintaining a better water quality in the tested AP system.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Selenium (Se) is an essential nutrient for humans, due to its antioxidant properties, whereas, to date, its essentiality to plants still remains to be demonstrated. Nevertheless, if added to the ...cultivation substrate, plants growth resulted enhanced. However, the concentration of Se in agricultural soils is very variable, ranging from 0.01 mg kg
up to 10 mg kg
in seleniferous areas. Therefore several studies have been performed aimed at bio-fortifying crops with Se and the approaches exploited were mainly based on the application of Se fertilizers. The aim of the present research was to assess the biofortification potential of Se in hydroponically grown strawberry fruits and its effects on qualitative parameters and nutraceutical compounds. The supplementation with Se did not negatively affect the growth and the yield of strawberries, and induced an accumulation of Se in fruits. Furthermore, the metabolomic analyses highlighted an increase in flavonoid and polyphenol compounds, which contributes to the organoleptic features and antioxidant capacity of fruits; in addition, an increase in the fruits sweetness also was detected in biofortified strawberries. In conclusion, based on our observations, strawberry plants seem a good target for Se biofortification, thus allowing the increase in the human intake of this essential micronutrient.
Microbial contamination and mold growth are common causes of strawberry deterioration during storage. The growing need for extending shelf-life while enhancing the overall quality of perishable ...fruits has generated increasing interest in the development of novel preservation technologies. This study used electrostatic spraying (ES) technology as an innovative and efficient technique for the application of edible alginate coating enriched with carvacrol and methyl cinnamate (natural antimicrobials) on fresh strawberries. The efficiency of the electrostatic technology was compared to non-electrostatic (conventional) spray (NES) technology in terms of transfer efficiency and coating evenness. Furthermore, physicochemical and textural parameters (such as weight loss, visible decay, firmness, surface color, total soluble phenolic content, and antioxidant capacity) of ES and NES coated fruits were studied and compared to uncoated controls. ES technology demonstrated higher transfer efficiency and evenness than NES, which led to a significant reduction of visible decay over uncoated controls. The delay in microbial spoilage by ES (11 days) was greater than by NES (10 days) and uncoated strawberries (7 days). ES coating significantly inhibited strawberry decay with only 5.6 % of infected fruits, compared to 16.6 and 8.3 % for control and NES fruits after 13 days of storage, respectively. At the end of 13 days of storage, ES coating demonstrated superior performance on strawberry firmness, color retention, and weight loss reduction. Additionally, no differences were observed between uncoated and coated fruits with regard to their antioxidant and total soluble phenolics.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Two selenium (Se) fertilization methods were tested for their effects on levels of anticarcinogenic selenocompounds in radish (Raphanus sativus), as well as other nutraceuticals. First, radish was ...grown on soil and foliar selenate applied 7 days before harvest at 0, 5, 10, and 20 mg Se per plant. Selenium levels were up to 1200 mg Se/kg DW in leaves and 120 mg Se/kg DW in roots. The thiols cysteine and glutathione were present at 2-3-fold higher levels in roots of Se treated plants, and total glucosinolate levels were 35% higher, due to increases in glucoraphanin. The only seleno-aminoacid detected in Se treated plants was Se-methyl-SeCys (100 mg/kg FW in leaves, 33 mg/kg FW in roots). The levels of phenolic aminoacids increased with selenate treatment, as did root total nitrogen and protein content, while the level of several polyphenols decreased. Second, radish was grown in hydroponics and supplied with 0, 5, 10, 20, or 40 μM selenate for 1 week. Selenate treatment led to a 20-30% increase in biomass. Selenium concentration was 242 mg Se/kg DW in leaves and 85 mg Se/kg DW in roots. Cysteine levels decreased with Se in leaves but increased in roots; glutatione levels decreased in both. Total glucosinolate levels in leaves decreased with Se treatment due to repression of genes involved in glucosinolates metabolism. Se-methyl-SeCys concentration ranged from 7-15 mg/kg FW. Aminoacid concentration increased with Se treatment in leaves but decreased in roots. Roots of Se treated plants contained elevated transcript levels of sulfate transporters (Sultr) and ATP sulfurylase, a key enzyme of S/Se assimilation. No effects on polyphenols were observed. In conclusion, Se biofortification of radish roots may be achieved via foliar spray or hydroponic supply. One to ten radishes could fulfill the daily human requirement (70 μg) after a single foliar spray of 5 mg selenate per plant or 1 week of 5-10 μM selenate supply in hydroponics. The radishes metabolized selenate to the anticarcinogenic compound Se-methyl-selenocysteine. Selenate treatment enhanced levels of other nutraceuticals in radish roots, including glucoraphanin. Therefore, Se biofortification can produce plants with superior health benefits.
Soilless cultivation is one of the best examples of the sustainable intensification concept due to the high use efficiency of its inputs. Managing the nutrient solution through a closed cycle system ...represents a crucial objective to be pursued, but the recovery of the nutrient solution requires chemical correction and sanitization. The application of non-thermal plasma (NTP) in agriculture promotes the safety of the nutrient solution, decreasing the use of chemicals. The aim of this study was to evaluate the effects of cold plasma on the nutrient depletion, yield, and qualitative traits of lettuce. A closed soilless system (nutrient film technique) was used to compare different NTP treatments: control, low ionization (LI), and high ionization (HI) in two successive lettuce cycles. No significant differences within the nutrient depletion trends were observed. The treated lettuce’s yield was 12% higher than that of the control, characterized by a higher total soluble solid content and a significantly higher electrical conductivity and titratable acidity than the control. The ion content was higher in HI plants, as were the contents of nitrogen, phosphorous, and potassium. In HI plants, the leaf pigments were higher, but no significant changes were observed for the antioxidant content. Cold plasma is a promising strategy that brings benefits to the crop.
Sub-optimal nitrogen (N) conditions reduce maize yield due to a decrease in two sink components: kernel set and potential kernel weight. Both components are established during the lag phase, ...suggesting that they could compete for resources during this critical period. However, whether this competition occurs or whether different genotypic strategies exist to optimize photoassimilate use during the lag phase is not clear and requires further investigation. We have addressed this knowledge gap by conducting a nutrient solution culture experiment that allows abrupt changes in N level and light intensity during the lag phase. We investigated plant growth, dry matter partitioning, non-structural carbohydrate concentration, N concentration, and
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N distribution (applied 4 days before silking) in plant organs at the beginning and the end of the lag phase in two maize hybrids that differ in grain yield under N-limited conditions: one is a nitrogen-use-efficient (EFFI) genotype and the other is a control (GREEN) genotype that does not display high N use efficiency. We found that the two genotypes used different mechanisms to regulate kernel set. The GREEN genotype showed a reduction in kernel set associated with reduced dry matter allocation to the ear during the lag phase, indicating that the reduced kernel set under N-limited conditions was related to sink restrictions. This idea was supported by a negative correlation between kernel set and sucrose/total sugar ratios in the kernels, indicating that the capacity for sucrose cleavage might be a key factor defining kernel set in the GREEN genotype. By contrast, the kernel set of the EFFI genotype was not correlated with dry matter allocation to the ear or to a higher capacity for sucrose cleavage; rather, it showed a relationship with the different EFFI ear morphology with bigger kernels at the apex of the ear than in the GREEN genotype. The potential kernel weight was independent of carbohydrate availability but was related to the N flux per kernel in both genotypes. In conclusion, kernel set and potential kernel weight are regulated independently, suggesting the possibility of simultaneously increasing both sink components in maize.
► The AOA increased from CT1 to CT2 (+62.4%), then decreased in CT3. ► Rosmarinic acid increased from CT1 to CT2 (+74.8%) to decrease again in CT3. ► First cuts are suitable for industrial food ...processing, CT3 for oil extraction.
In Italy basil (Ocimum basilicum L.) is mainly used to make a sauce called “pesto” and in order to produce this sauce industrially, the cultivated basil is cut several times during the growing cycle. This study was conducted to evaluate the effect of three cuts timing (CT1–CT3) on biomass productivity, oil content and chemical composition of three basil cultivars (CV1–CV3) in order to check the most suitable techniques to produce high quality pesto sauce. The production of the cultivars differed, with CV3 giving the lowest production (15.3tha−1), whereas CV1 and CV2 were not significantly different with quantities over 18tha−1. The essential oil content in CV1 differed from CV2, with 14.95 and 11.89Lha−1 for each cut respectively. However, the highest oil content (%) was recorded in CV3 with values 7.4% and 17.0% higher than CV1 and CV2 respectively.
The highest antioxidant activity (AOA) was recorded in CV3 with almost 20,000mg Fe2+Ekg−1fw followed by CV2 and CV1, where values did not exceed 7500mg Fe2+Ekg−1fw. In terms of cuts, the AOA increased from CT1 to CT2 (+62.4%), then decreased in CT3. Among phenolics, rosmarinic acid was the most important from a quantitative point of view and was higher in CV3 with more than 1000mgkg−1fw, followed by CV2 and CV1. It increased from CT1 to CT2 (+74.8%) to decrease again in CT3 (−36.7%). The most relevant content of caffeic and ferulic acid was observed in CV3 and also in CT3 due to the high stress caused by cuts.
Consequently, within the same crop cycle, basil could offer several options to the producer. The first two cuts are suitable for fresh consumption and industrial food processing, CT3 for essential oils extraction for cosmetic and pharmaceutical industries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The COVID-19 pandemic is causing many victims worldwide and has generated a serious economic crisis. Substantial changes have occurred in the food and ornamental production chains. The aim of the ...present review has been to summarize some of the main effects that the pandemic is having on horticulture and on the new habits of people. Infections and quarantine measures have prevented the regular flow of certain goods and of connected services. Cases of shortages and/or surpluses, a lack of the availability of labor, and a reduction in demand for some food products and flowers have occurred. New food production approaches have emerged and a reconnection between farmers and consumers has been spreading, thereby facilitating product distribution. Moreover, during the forced isolation, people have had to face periods of stress. The benefits that can be derived from leisure activities related to flowers and ornamental plants, and from access to nature and urban green spaces are increasingly being recognized as relevant. The seriousness of the pandemic will inevitably lead to lasting changes. Therefore, the vulnerability of the pre-COVID-19 distribution chains should be considered and a new food production chain should be drawn up, to increase the resilience of such systems.
The aim of this study was to evaluate the agronomical and environmental effects of digestate solid fraction (DSF) used as fertiliser in a vegetable crop succession (green bean, savoy cabbage, cabbage ...and cauliflower) in Northeast Italy (45°20’ N; 11°57’ E). Three fertilisation treatments were tested using DSF to substitute 0% (Tmin), 50% (T50) and 100% (T100) optimal level of mineral nitrogen fertilisation. The experiment was carried out from 22nd May 2014 (green bean sowing) to 3rd June 2015 (cabbage harvest). Summer and spring crops did not show significantly different marketable yield among fertilisation treatments with an average value (±standard error) of 9.0±0.5, 9.9±1.2 and 51.3±6.4 Mg ha–1 for green bean, cauliflower and cabbage, respectively. Lower DSF fertilisation effect was monitored on winter crop (savoy cabbage) with a marketable yield reduction of -35.1% than mineral fertilisation (25.9 Mg ha–1), whereas the T50 treatment was not significantly different compared to the two previous ones. Crop species significantly influenced the N use efficiencies with negative recovery and use efficiency indexes for the DSF fertilisation treatments. Soil CO2 emissions were not significantly influenced by fertilisation in all studied crops with median values always lower than 1 g m–2 h–1.
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