Soilless Culture Research Articles

The Impact of Nutrient Solution Electrical Conductivity on Leaf Transcriptome Contributing to the Fruit Quality of Cucumber Grown in Coir Cultivation

Soilless cultivation is increasingly utilized in supplying essential nutrients for greenhouse crops. However, the impact of coir cultivation under varying electrical conductivity (EC) conditions on cucumber growth and fruit quality, particularly through the regulation of gene expression during the vegetative stage, remains uncertain. In this study, we performed metabolic measurements on cucumber in both vegetative and reproductive stages under three different EC conditions and found metabolic products such as some primary metabolites (cellulose, many uncharged amino acids) and some secondary metabolites (rutin, cucurbitacin B) accumulated the most under EC of 5 dS·m−1. Next, we conducted transcriptome profiling in cucumber leaves, revealing that the function of genes significantly regulated by EC was associated with photosynthesis, many anabolic processes, and membrane transport. Finally, a set of genes contributed to metabolites related to the fruit quality of cucumber were identified by the Orthogonal Partial Least Squares (O2PLS) analysis, including genes involved in the biosynthesis of amino acids, polysaccharides, and many secondary metabolites. Taken together, these findings suggest that coir cultivation in greenhouses with moderate EC can induce a transcriptome-wide change in gene expression, thereby contributing to enhancing the abundance of metabolites associated with cucumber fruit quality.

Impacts of Light Exposure and Soil Covering on Sweet Potato Storage Roots in a Novel Soilless Culture System

Soilless culture systems, which promote plant growth and enable the precise control of the root-zone environment, have yet to be fully established for sweet potatoes. In this study, we developed a soilless culture system and examined the effects of soil covering and light exposure on the storage roots of sweet potatoes. Sweet potato seedlings with induced storage roots were transplanted into five systems: a previously developed pot-based hydroponics system (Pot), an improved version with storage roots enclosed in a plastic box and covered with a soil sheet (SS), the SS system without the soil sheet (SD), the SD system with light exposure to storage roots after 54 days (SL), and a deep flow technique (DFT) hydroponics system. Our study enabled the time-course observation of storage root enlargement in the SS, SD, and SL systems. In the SL system, light exposure suppressed the storage root enlargement and reduced epidermal redness. No storage root enlargement was observed in the DFT system, even at 151 days after transplantation. Light exposure in the SL system increased the chlorophyll and total phenolic contents in the cortex beneath the epidermis, while the starch content was the lowest in this system. These findings indicate that the developed system can induce normal storage root enlargement without soil. Additionally, the observed changes in growth and composition due to light exposure suggest that this system is effective for controlling the root-zone environment of sweet potatoes.

Effects of NH4 +-N: NO3 --N ratio on growth, nutrient uptake and production of blueberry (Vaccinium spp.) under soilless culture.

Blueberry (Vaccinium corymbosum) is a small pulp shrub, which prefers to grow on a soilless culture. For soilless culture, nutritional management remains typically vital for blueberry production. However, the effect of different nutritional treatments on blueberry growth and production is largely unknown. This study was designed to investigate to formulate a specific nutritional treatment for blueberry. The results showed that NH4 +-N: NO3 --N ratios significantly affected the growth, nutrient uptake, physiological characteristics, and flowering, as well as the fruiting characteristics of blueberry plants. The number of shoots and top projection area was increased considerably by 25:75 treatment. In contrast, 50:50 treatment promotes plant height, shoot length, and stem thickness, increasing chlorophyll contents, photosynthetic capacity, and P, Ca, and Mg in leaves. In contrast, 50:50 treatment promotes the flowering fruiting rate and prolongs the blueberry flowering period. The maximum soluble sugar contents were noted in 25:75, while maximum starch contents were reported in the 50:50 treatment. The treatments 100:0 and 75:25 promote early flowering and accelerate fruit set. Notably, NH4 +-N: NO3 --N ratios; 50:50 treatment significantly encourages plant growth, nutrient uptake, chlorophyll contents, photosynthetic capacity, and fruit setting rate in blueberry plants. These findings suggested that NH4 +-N: NO3 --N ratios 50:50 is the most appropriate treatment that significantly promotes vegetative growth and enhances production in blueberry plants. This study provides valuable information for improved blueberry production under a controlled environment.

Assessment of bioactive compounds, antioxidant properties and morphological parameters in selected microgreens cultivated in soilless media

The study investigated the effect of soilless media (burlap), on the morphological traits and antioxidant activities of microgreens from Brassicaceae, Amaranthaceae, and Linaceae families. The results revealed significant variations were observed in the selected morphological, biochemical composition, and antioxidant capacity of the microgreens. The radish sango and microgreens showed superior morphological characteristics compared to other microgreens. The elemental composition analysis revealed consistent moisture, ash, fat, fiber, and protein content across all families. The results revealed significant variations in the biochemical composition and antioxidant capacity of the microgreens, depending on the growing medium and between microgreens. Notably, microgreens differed in photosynthetic pigment profiles, with flaxseed and cabbage showing the highest chlorophyll content of 26.59 to 27.18 µg/g, FW and carotenoid content in a range of 3.74 to 6.39 µg/g, FW was observed in microgreens. The radish sango and beetroot microgreens exhibited elevated anthocyanin levels of 27.94–28.25 µmol/100 g, FW. Biochemical analysis indicated varying levels of ascorbic acid (177.58 to 256.46 mg/100 g, FW), total glucosinolate content (4.09 to 47.38 µmol/g, FW), phenolic content (131.44 to 298.56 mg GAE/100 g, FW), and flavonoid content (10.94 to 18.14 mg QUE/100 g, FW) were observed in selected microgreens families. Radish sango microgreens demonstrated the highest DPPH (76.82%, FW) and ABTS (88.49%, FW) radical scavenging activities, indicating superior antioxidant potential. The study showed that Brassicaceae microgreens are particularly rich in bioactive and antioxidant properties. Additionally, studies could assess the economic feasibility and scalability of soilless cultivation methods for microgreens to support their inclusion in sustainable agricultural practices and health-promoting diets.

A comparative study between the efficacy of fertigation and spraying procedures in terms of the content of Cadmium (Cd) and Arsenic (As) in greenhouse cucumber.

A comparative study between fertigation and spraying procedures in terms of the status of Cadmium (Cd) and Arsenic (As) in greenhouse cucumber was conducted as a two-factor split plot based on a randomized complete block design with three replications at the Soil and Water Research Institute, Karaj, Iran in 2023. The main and sub-factors were respectively fertigation and spraying that were used in two levels [the maximum permissible concentration of Cd and As in granular triple super phosphate fertilizer (25ppm Cd and 50ppm As) and the minimum permissible concentration of these metals in granular triple super phosphate fertilizer (5ppm Cd and 5ppm As)]. Spraying was done in three modes (spraying of leaves, leaves and fruit, and fruit). On average, the results showed that the order of the concentration of Cd in plant tissues (DW) was as leaf (0.284mg/kg) > fruit peel (0.102mg/kg) > fruit peel + flesh (0.054mg/kg) > fruit flesh (0.044mg/kg). This order for As was as leaf (0.608mg/kg) > fruit flesh (0.127mg/kg) > fruit peel + flesh (0.109mg/kg) > fruit peel (0.072mg/kg). Based on the measurements, the spraying procedure accumulated more amounts of Cd and As in the fruit (i.e., peel + flesh) than the fertigation procedure. In general, it is concluded that under soilless culture, the status of heavy metals in plant tissues of greenhouse cucumber is related to the nature of the metal, the organ exposed to the metal, and the fertilization procedure. Because there is the risk of contamination of vegetables grown in the areas fertigated and sprayed with poor-quality nutrient solutions in terms of the content of heavy metals, the frequency of fertigation and spraying needs to be monitored continuously for the quality of the vegetables cultivated in greenhouses.

Application and Development of Hydrogel in Soilless Culture

AbstractSoilless culture refers to the method of cultivating plants without soil as a growing medium, and the use of hydrogel in soilless culture overcomes many technical difficulties, but there are many applications that just stay at the experimental level, with fewer applications in fields. Although many new functionalized hydrogels may help to overcome the shortcomings of traditional media and give them more functionality, little research on hydrogels over the past decades has been reflected in soilless culture techniques. This paper details the concept and development of soilless culture, as well as several applications of hydrogels in soilless culture, including the use of hydrogels as soilless culture substrates and the application of hydrogel membranes. The important roles of different types of hydrogels in soilless culture, such as antimicrobial properties, salt tolerance and high water absorption, are highlighted, and these excellent properties largely overcome a series of drawbacks of traditional cultivation methods. The application of hydrogels in pest control is also discussed. Hydrogel applications to soilless culture have better prospects for the creation of more promising multifunctional composite hydrogel membranes and hydrogel substrates capable of supporting plants throughout their growth cycle.

Light emitting diodes for the improvement of postharvest quality of wild rocket in soilless and soil-bound cultivation systems

Wild rocket (Diplotaxis tenuifolia (L.) DC cv. Dallas) is a leafy green vegetable appreciated for its pungent taste and healthy properties, often consumed as a ready-to-eat product. The cultivation system is crucial in determining the overall quality, while postharvest storage is fundamental for preserving nutritional quality, phytochemicals, and vitamins. This study aimed to investigate the phytochemical content and microbiological quality of soilless (SS) and soil-bound (SB) wild rocket during cold postharvest storage under blue, red, and green Light Emitting Diode (LED). Blue LED increased chlorophylls and carotenoids in SB after two days of storage, and chlorophyll a in SS after seven days. Furthermore, it reduced H2O2 levels after two days (SS and SB) and lipid peroxidation in SB. Red LED increased phenols in both SS and SB but was detrimental to chlorophyll, carotenoids, and oxidative markers. Green LED had less significant effects. Microbiological growth varied with LED treatment: green light increased mesophilic bacteria in SB, and red light did so in SS by day four, while blue light reduced bacterial growth at the end of storage. Overall, Blue LED was the most effective LED in preserving postharvest quality. Soilless cultivation was particularly beneficial in reducing lipid peroxidation and maintaining cell membrane integrity during long-term storage, and it might also be more effective in preserving ascorbic acid. Conversely, soil-bound cultivation methods could enhance initial polyphenol content or better preserve it during early storage. This study highlights the complex interplay of pre-harvest conditions, postharvest quality, and shelf-life performance.

Construction waste as a filler of denitrification biofilter for nitrate utilization from wastewater: Characteristics, performance, microbial community and soilless culture

Construction waste (CW) is produced in large quantities, resulting in severe land occupation and resource depletion. This study utilized CW as fillers to construct a denitrification biofilter (DNBF-CW) for treating secondary effluent from wastewater plants. Performance and mechanism were analyzed by water quality, biomass and its distribution, physicochemical characteristics, microbial community structure, extracellular polymeric substances and protein secondary structure analysis. Results indicated that DNBF-CW achieve NO3−-N and chemical oxygen demand (COD) removal efficiencies (RE) of 97 % and 70 %. The β-sheet of DNBF-CW increased from 47 % to 58 %, accompanied by decrease in random curls from 22 % to 0. Post-use CW showed potential as soilless cultivation substrates, boosting germination rates by 42 ± 7 %. Mechanism investigations elucidated that ZX3 improved efficiency by modulating microbial community composition, with Pseudomonas reaching 37 %. This study shows the multiple use of construction waste, which presents a novel, efficient, and eco-friendly solution for water treatment.

A smart monitoring and observation framework for aquaponics ecosystem

Aquaponics is a sustainable and efficient agricultural system that integrates aquaculture with agriculture. This system integrates Internet of Things (IoT) technology in aquaponics systems with the potential to change sustainable agriculture by combining farming of fish (aquaculture) and soilless cultivation of plants (hydroponics) into a single, efficient ecosystem. This paper explores the design and development of a smart aquaponics system that allows aquaponic farming at commercial scale feasible, leveraging IoT to continuously gather data through various sensors, monitor environmental conditions, and automate control processes. The proposed system architecture is based on a three-tier model, ensuring scalability and maintainability. The proposed system consists of a three-layer architecture: the Perception Layer for measuring different environmental factors and controlling them, the Network Layer for data transmission, and the Application Layer for data storage, manipulation, and user interaction. The key components include sensors for monitoring pH, humidity, temperature, sunlight, oxygen levels, and water proximity; devices such as lights, water pumps, fans, and oxygen pumps for environmental control; and an ESP8266 microcontroller for system management. The system's software is developed using C# DOT NET CORE 8.0, React, MySQL, C, and Arduino. The system allows users the ability to maintain optimal conditions for fish and plant growth, notify users of irregularities, and allow remote control through a web application, proving it to be an intelligent, flexible, low-cost, and stable solution for large-scale aquaponics.

The influence of planting density on the oil and fatty acids content of soybean in hydroponic and soil conditions of the Ararat Valley

Background: Plant seed oils are major renewable resources from nature that can be used in multiple applications. Oils and fats are a vital component of human diets. About 1/3 of the daily energy requirements of a healthy diet come from fats. Each branch of the food industry has its own demands for the fatty acid composition of seed oils. High amounts of polyunsaturated fatty acids are a requirement of healthy diets. However, food manufacturers need highly saturated fatty acids because they need oil that is resistant to high temperatures and oxidation. Soybean oil is second only behind palm oil as the most commercially abundant plant oil globally. Soybean has been recognized for its agricultural importance and their various positive effects on human health. Objective: to identify the quantitative changes of soybean fatty acids depending on the planting density and growing conditions in the Ararat Valley of Armenia. Methods: Soybean was grown in hydroponic and soil conditions of the Ararat Valley. The seeds were sown in the middle of April. Experiments were carried out in hydroponic equipment and soil with different planting densities (30, 50, 70 and 90 plants/m2). The oil content was measured by using the pulsed nuclear magnetic resonance method. The composition of fatty acids in seed oil was analyzed by chromatographic method on "Chromatec Crystal 5000" GC. Results: Oil content ranged from 19.6% to 24.4% in all variants. The maximum content was registered in soil with 30 plant/m2 planting density. Linoleic acid content ranged from 46.35 to 51.28% of the total fatty acid content, regardless of planting density and growing media. The content of linolenic acid ranged from 4.13 to 5.11% in all variants. The maximum content of ω-3 and the minimal content of ω-9 was recorded in hydroponics at 30 plants/m2 planting density. The highest percentage of stearic acid was observed in the soil variant with a planting density of 30 plants/m2. Interestingly, the variants did not differ in the total content of the 5 main fatty acids (98.84-98.95%). Growing medium had no significant effect on the total saturated fatty acids content; in all variants it ranged from 14.29% to 14.83%. Total unsaturated fatty acids content ranged from 85.2% to 85.7%. The hydroponic variant with a planting density of 30 plants/m2 had the lowest ratio of ω-6 and ω-3 fatty acids (10:1). Conclusion: Planting density and growing media had a significant influence on the content of monounsaturated and polyunsaturated fatty acids. Under hydroponic conditions the lowest content of monounsaturated and the highest content of polyunsaturated fatty acids were observed at the lowest planting density (30 plants/m2), which can be used as a functional food for daily consumption. Keywords: Glycine max (L.) Merr., soilless culture, ω-3, ω-6, ω-9, saturated acids.

Biostimulants Enhance the Nutritional Quality of Soilless Greenhouse Tomatoes.

The application of biostimulants in vegetable cultivation has emerged as a promising approach to enhance the nutritional quality of crops, particularly in controlled environment agriculture and soilless culture systems. In this study, we employed a rigorous methodology, applying various biostimulants amino acids, Plant Growth-Promoting Rhizobacteria (PGPR), fulvic acid, chitosan, and vermicompost along with mineral fertilizers, both foliar and via the roots, to soilless greenhouse tomatoes during spring cultivation. The experiment, conducted in a coir pith medium using the 'Samyeli F1' tomato cultivar, demonstrated that plants treated with biostimulants performed better than control plants. Notable variations in nutritional components were observed across treatments. PGPR had the best effects on the physical properties of the tomato fruit, showing the highest fruit weight, fruit length, equatorial diameter, fruit volume, fruit skin elasticity, and fruit flesh hardness while maintaining high color parameters L, a, and b. PGPR and fulvic acid demonstrated significant enhancements in total phenolics and flavonoids, suggesting potential boosts in antioxidant properties. Amioacid and vermicompost notably elevated total soluble solids, indicating potential fruit sweetness and overall taste improvements. On the other hand, vermicompost stood out for its ability to elevate total phenolics and flavonoids while enhancing vitamin C content, indicating a comprehensive enhancement of nutritional quality. In addition, vermicompost had the most significant impact on plant growth parameters and total yield, achieving a 43% increase over the control with a total yield of 10.39 kg/m2. These findings underline the specific nutritional benefits of different biostimulants, offering valuable insights for optimizing tomato cultivation practices to yield produce with enhanced health-promoting properties.

Extracellular Fragmented Self-DNA Displays Biostimulation of Lettuce in Soilless Culture

Extracellular Fragmented Self-DNA Displays Biostimulation of Lettuce in Soilless Culture

SEED POTATO PRODUCTIVITY AS INFLUENCED BY ELECTRICAL CONDUCTIVITY OF THE NUTRIENT SOLUTION IN SOILLESS MEDIA DURING SPRING SEASON IN SUBTROPICAL REGIONS OF N- W INDIA

Soilless cultivation under controlled conditions is used for rapid multiplication of early generation virus-free potato seed using aeroponics and other mediums. The plant growth under these systems is affected by different factors like soilless media, nutrient solution concentration used, environment, genotype etc. Besides the composition of nutrient solution its electrical conductivity (EC) influences availability of nutrients and affects plant growth and yield. The two-factorial study on water source and EC was carried out on a cocopeat based medium for a nutrient efficient variety Kufri Gaurav. Well sprouted aeroponically produced minitubers of the variety were planted (at 30 x 15 cm planting density) in soilless medium filled troughs placed under net house. The water source Normal tap water was compared with RO (demineralized) water, while EC was considered at three levels 1.0, 1.5 and 2.0. The results indicated a proficient growth of the genotype at EC 2.0 (plant height, number of leaves, stem diameter, leaf length and number of stems). However, for the yield characters, EC 1.0 was found to produce both higher number of tubers, yield as well as harvest index per meter square. Based on the observations it can be inferred that at lower EC the partitioning of the photosynthates is towards the sink (tubers) as compared to the vegetative growth, which would be more desirable under the soilless systems, where limited/ managed canopy growth is more desirable, with higher productivity. The study also indicated virus free seed production in soilless medium during the spring season (seed plot period lasts up to December) in northwestern plains of India under net house, giving indication for successive/ multiple seed crops under soilless controlled conditions.

Impact of CO2 Enrichment on Growth, Yield and Fruit Quality of F1 Hybrid Strawberry Grown under Controlled Greenhouse Condition

Carbon dioxide enrichment inside a greenhouse is a sustainable approach to increasing crop production worldwide. Recently, the F1 hybrid strawberry became an alternative to runner-propagated cultivation as an innovative method to shorten the production period and increase strawberry production. This work aims to present CO2 enrichment as a sustainable tool that improves the yield in a controlled greenhouse and addresses the efficiency of three F1 hybrid strawberry varieties grown under Saudi Arabian conditions. A greenhouse experiment was conducted at the National Research and Development Center for Sustainable Agriculture (Estidamah), KSA, to study the impact of two CO2 levels (400 ppm (“ambient”) and 600 ppm (“enrichment”)) on the growth, photosynthesis traits, fruit yield and fruit quality of three F1 hybrid strawberry varieties grown under soilless culture conditions. The results show that CO2 enrichment significantly improved the phenotyping of strawberry growth traits at 60 days post-transplanting. The physiological response of the varieties to CO2 enrichment reveals a significant increase in the photosynthetic rate (129.7%) and intercellular CO2 (43.7%) in the leaves of strawberry exposed to CO2 enrichment rather than in ambient conditions, combined with a significant increase in the number of fruits per plant (27.5%) and total fruit yield (42.2%). A similar pattern was observed with varieties D and S in terms of fruit number, length and diameter. However, CO2 at 600 ppm promoted total soluble solid accumulation and vitamin C for the tested varieties. In contrast, CO2 enrichment significantly decreased nitrogen, phosphorus, potassium and magnesium accumulation in the leaves of the exposed plants in comparison to 400 ppm of CO2. These results suggest that increasing CO2 enrichment could contribute to an increase in strawberry yield and nutritional value and demonstrate that understanding the response of each variety to CO2 enrichment is important to support selecting suitable greenhouse strawberry varieties to improve crop yield.

Mechanisms of the effect of high-performance ester composite materials on plant growth under soilless conditions

The utilization of high-performance ester materials in addressing soil erosion and conserving water remains a crucial area of research in soil remediation. Currently, however, the mechanism underlying the role of these materials in vegetation restoration remains unclear, hampering the accurate determination of the optimal ratio of high-performance ester composite materials for soil enhancement. To address this issue, this study examines the mechanism of how high-performance ester composite materials affect the germination and growth of plant seeds through soilless cultivation experiments. The results revealed that the high-performance ester composite materials significantly enhanced seed germination ability and fostered plant seedling growth. Notably, the promotional effects of the ester adhesive and water-retaining materials within the high-performance ester composite varied. Specifically, the adhesive material significantly spurred radicle development, while the water-retaining material significantly accelerated germ growth. Varying concentrations of adhesive materials exerted distinct effects on plant growth. In particular, a small amount of adhesive materials enhanced seed germination, whereas excessive amounts exhibited inhibitory effects. Consequently, the optimal adhesive materials dosage conducive to plant growth and the optimal weight ratio of adhesive to water-retaining materials were ascertained. Additionally, the underlying mechanism of high-performance ester composite materials influence plant growth was elucidated. Overall, this research offers a theoretical foundation for the optimal ratio adjustment of high-performance ester composite materials to optimize soil improvement efforts.

Greenhouse farming: Hydroponic vertical farming- Internet of Things (IOT) Technologies: An updated review

This review paper of literature highlights the importance of greenhouse urban farming technology, hydroponics, aeroponics, aquaponics, vertical farming and applications of Internet of Things (IOT) technologies. The greenhouse farming is a well known modern agriculture technology for optimal plant growth. Hydroponics, a soilless cultivation technique using nutrient solutions under controlled conditions, is used for growing vegetables, high-value crops, and flowers. Vertical farming is a popular trend in hydroponics that involves stacking multiple layers of plants in a vertical arrangement. This farming method saves space, reduces water usage, and increases yields per square foot of growing area. In comparison to conventional greenhouse cultivation, hydroponics requires less fertilizer, pesticides, and water due to the precise control over their distribution. The term “Internet of Things (IOT)” is a system of interconnected computing devices, sensors, objects, microcontrollers, and cloud servers that can transmit data across a network and control other devices remotely without human intervention. A better management of nutrient solution in hydroponic systems requires optimum pH, electrical conductivity (EC), or ions concentration. The three main greenhouse farming gases (GHGs) emissions in hydroponics hi-tech urban farming are nitrous oxide, methane and carbon dioxide (CO2). To measure the levels of CO2 in hydroponics, the more intermediate to advanced grower can use a CO2 monitoring and controllers system. Hydroponic vertical farming is in infancy in India. Although hydroponic vertical farming units for production of crops like strawberry, lettuce and other leafy vegetables, foliage and flowers are functioning in major metros of India. However, the organized hydroponic vertical farms for production of food crops are not available in India. Therefore, only a few successful hydroponic vertical farms have been built in India mainly due to the initial high price tag on construction and the cost of maintaining them afterwards. Another disadvantage is carbon footprint of hydroponic vertical farming is very high, and discourages its applications.

Efficacy of slow sand filtration enriched with Trichoderma atroviride in the control of Rhizoctonia solani in soilless culture

Soilless cultivation is increasingly common, but the nutrient-rich drainage from substrate cultivation is often discarded. However, drainage can be safely reused if previously disinfected. Slow sand filtration (SSF) is a low-cost, ecological, and effective method for water disinfection, primarily through biological control. Enhancing SSF with antagonistic microorganisms is not well-studied. Additionally, SSF has not been tested to control Rhizoctonia solani, a phytopathogen that can be spread by irrigation water. Therefore, the objective of his work was to test the efficacy of a slow sand filter improved through the inoculation of the antagonistic fungus Trichoderma atroviride, evaluating its suppression capacity against Rhizoctonia solani spread by the irrigation water in a closed substrate cultivation of cucumber (Cucumis sativus). Five experiments were conducted, testing the presence and absence of a sand filter, T. atroviride, and R. solani in each trial. Median disease severity was expressed on a scale of 1–5. The improved SSF increased disease control percentage by 49% compared to SSF alone and by 86% compared to no disease control method. In some experiments, SSF with T. atroviride totally controlled R. solani. The results confirm that biologically enhanced SSF with T. atroviride can effectively disinfect drainage in closed soilless cultivation systems infected with R. solani.

Rapid Reduction of Phytotoxicity in Green Waste for Use as Peat Substitute: Optimization of Ammonium Incubation Process.

The rapid growth of the horticultural industry has increased demand for soilless cultivation substrates. Peat, valued for its physical and chemical properties, is widely used in soilless cultivation. However, peat is non-renewable, and over-extraction poses serious ecological risks. Therefore, sustainable alternatives are urgently needed. Ammonium incubation, a novel method to reduce phytotoxicity, offers the potential for green waste, a significant organic solid waste resource, to substitute peat. This study optimized the ammonium incubation process to reduce green waste phytotoxicity. It systematically examined different nitrogen salts (type and amount) and environmental conditions (temperature, aeration, duration) affecting detoxification efficiency. Results show a significant reduction in phytotoxicity with ammonium bicarbonate, carbonate, and sulfate, especially carbonate, at 1.5%. Optimal conditions were 30 °C for 5 days with regular aeration. Under these conditions, ammonium salt-treated green waste significantly reduced total phenolic content and stabilized germination index (GI) at a non-phytotoxic level (127%). Using treated green waste as a partial peat substitute in lettuce cultivation showed promising results. This low-cost, low-energy method effectively converts green waste into sustainable peat alternatives, promoting eco-friendly horticulture and environmental conservation.

Evaluating the Performance of Cocopeat and Volcanic Tuff in Soilless Cultivation of Roses.

Roses are increasingly being grown in soilless systems to increase productivity and reduce the challenges associated with soil-based cultivation. This study investigates the effects of using cocopeat and volcanic tuff substrates, the particle size of tuff, and substrate depth on the growth and flower quality of roses (Rosa hybrida L. cv. top secret) grown under greenhouse conditions. The treatments were cocopeat, tuff, cocopeat-tuff mixture, and tuff of particle size of 2 to 4 mm, 0 to 4 mm, and 0 to 8 mm at depths of 20 cm and 40 cm. The results showed that cocopeat had the highest water-holding capacity and photosynthetic rate. Tuff substrates had higher chlorophyll content throughout the growing season. Although flower numbers per plant in cocopeat and tuff from 0 to 8 mm at a depth of 20 cm were statistically similar, tuff from 0 to 8 mm had longer flowering stems and larger post-harvest flower diameters than cocopeat. An increase in the tuff depth from 20 to 40 cm decreased the flower number and main stem diameter. In conclusion, while cocopeat promotes rapid initial growth, volcanic tuff substrates, particularly tuff from 0 to 8 mm at a depth of 20 cm, provide long-term benefits for flower quality and plant health.

Effect of Substrates and Nutrient Solution Concentrations on Growth and Yield of Cardamom (Amomum testaceum Ridl.) in Soilless Culture

This research aimed to investigate the effects of the substrates and nutrient solutions on the growth and yield of cardamom in soilless culture. The experimental design was 2x3 Factorial in Completely Randomized Design with 5 replications. First factor consisted of coconut coir dust and coconut husk chips and the second factors were 3 nutrient solution concentrations; EC=1.00, 2.00 and 3.00 mS/cm. The experiment was carried out during July to December, 2021. The results showed that cardamom grown using coconut husk chips with nutrient solution concentration of EC= 3.00 mS/cm yielded the highest plant weight (256.00 g/plant) and the highest number of plants (21.30 plant/pot), respectively. For the analysis of interaction effect between substrates and nutrient solution concentrations, it was found that cardamom grown by using chopped coconut husks at EC 3.00 mS/cm gave the highest number of plants (23.60 plants/pot). Therefore, to produce shoots for sale, cardamom should be planted using coconut husk chips at EC 3.00 mS/cm in order to obtain the best cardamom growth and yield.