Optimal Plant Growth Research Articles

Analysis of Soil Viability Monitoring System for In-House Plantation Growth Using an Internet of Things Approach

Houseplant cultivation has become increasingly popular, allowing individuals to bring nature into their homes. However, successful indoor gardening requires careful monitoring of soil parameters to ensure optimal plant growth. To address this need, sensor technology and Internet of Things (IoT) devices are utilized to monitor soil temperature and moisture levels, which play crucial roles in plant growth. Various soil factors are sensed and collected using an IoT-based microcontroller, with data transmission facilitated by a Message Queue Telemetry Transport (MQTT) broker. Visualization of the data is achieved through the Node-RED programming tool, simplifying dashboard creation for easy monitoring. Furthermore, the collected data is stored in a MySQL server, enabling further analysis through SQL queries. The day is divided into four quarters with six-hour intervals, allowing for soil data collection using temperature and moisture sensors. The resulting information on the dashboard facilitates informed decision-making to enhance soil conditions for optimal indoor plant growth. Experimentation has revealed a reduction in soil temperature of 3°C during daytime due to air conditioning operation, while soil moisture content remains consistently between 60 to 65% during early mornings and late evenings. Additionally, emphasis is placed on remote management using IoT systems, enabling monitoring of plant growth even when access is limited. Overall, monitoring soil factors using IoT technology offers a promising approach to optimizing indoor gardening practices and minimizing environmental resource consumption.

Biology and host specificity of the stem-boring weevil Gasteroclisus tricostalis, a candidate agent for the biological control of fireweed (Senecio madagascariensis) in Australia

ABSTRACT Senecio madagascariensis Poiret (Asteraceae) is a target for biological control in Australia, due to substantial impacts on agriculture and native environments. Studies in the plant’s native range in South Africa prioritised the stem-boring weevil Gasteroclisus tricostalis (Thunberg) (Curculionidae) as a candidate agent. In this study, we assessed the biology and host specificity of G. tricostalis during laboratory trials conducted in both South Africa and Australia. No-choice trials in South Africa revealed that, despite oviposition on 15 non-target Senecio species (seven Australian and eight South African), there was significantly lower oviposition relative to S. madagascariensis, with no survival to pupation or adulthood on any non-target species. In contrast, no-choice tests in quarantine in Australia, recorded oviposition on 12 non-target Australian native Senecio species, with oviposition on two species not significantly different to that on S. madagascariensis. Furthermore in Australia, larvae developed to adulthood on five non-target species, in numbers that were not significantly different to S. madagascariensis. These discrepancies can mostly be explained by the lower phylogenetic distance from S. madagascariensis to the susceptible non-target species tested in Australia and, likely, optimal plant growth conditions in quarantine in two cases. Although no-choice tests are renowned for their conservative nature, preliminary paired-choice trials in both South Africa and Australia failed to demonstrate clear oviposition preferences for S. madagascariensis. These results suggest that, given the high diversity of the genus Senecio in Australia, the weevil is likely unsuitable for release and further trials were suspended.

OPDA signaling channels resource (e-) allocations from photosynthetic ETC to plastid cysteine biosynthesis in defense activations.

A primary precursor of jasmonates 12-oxo-phytodienoic acid (OPDA) is an autonomous hormone signal that activates and fine-tunes plant defense responses, as well as growth and development. However, the architecture of its signaling circuits remains largely elusive. Here we describe that OPDA signaling drives photosynthetic reductant powers toward the plastid sulfur assimilations, incorporating sulfide into cysteine. Under stressed states, OPDA -accumulated in the chloroplasts- binds and promotes cyclophilin 20-3, an OPDA receptor, to transfer electrons from thioredoxin F2, an electron carrier in the photosynthesis reaction, to serine acetyltransferase 1 (SAT1). The charge carrier (H+, e-) then splits dimeric SAT1 trimers in half to signal the recruitment of dimeric O-acetylserine(thiol)lyase B, forming a hetero-oligomeric cysteine synthase complex (CSC). The CSC formation and its metabolic products (esp., glutathione) then coordinate redox-resolved retrograde signaling from the chloroplasts to the nucleus in adjusting OPDA-responsive gene expressions such as GLUTAREDOXIN 480 and CYTOCHROME P450, and actuating defense responses against various ecological constraints such as salinity and excess oxidants, as well as mechanical wounding. We thus conclude that OPDA signaling regulates a unique metabolic switch in channeling light input into outputs that fuel/shape a multitude of physiological processes, optimizing plant growth fitness and survival capacity under a range of environmental stress cues.

Assessing the impact of leachate irrigation on Medicago sativa (alfalfa) growth, enzymatic responses, and heavy metal accumulation.

In light of the increasing water scarcity and the need for sustainable waste management, the use of landfill leachate for irrigation has emerged as both a solution and a concern, posing potential risks to soil health and plant vitality. This study examined the multifaceted impacts of leachate irrigation on the soil characteristics, plant growth, and enzymatic activities of Medicago sativa (M. sativa). By exposing alfalfa to different concentrations of leachate, we assessed the influence on heavy metal accumulation, physiological parameters, and enzyme functions. The physicochemical profile of the leachate indicated that the pH was within acceptable limits, but the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and concentrations of lead (Pb) and aluminum (Al) exceeded regulatory standards. Morphological parameters exhibited dual effects: stimulation at lower leachate doses and inhibition at higher leachate doses. Our findings show that soil acts as a buffer, reducing heavy metal uptake by plants. Enzymatic activities, including catalase, peroxidase, and succinate dehydrogenase, fluctuated significantly at higher leachate concentrations, indicating stress responses. This research underscores the interplay between leachate irrigation, plant physiology, and soil health, emphasizing sustainable management to optimize plant growth and minimize environmental impacts. It also stresses refining leachate application protocols to preserve soil and ecosystem health.

Efficacy of nano urea in replacing conventional nitrogen application and its effect on fruit quality in strawberry

In a study conducted on strawberry cv. Winter Dawn, the combined application of nano urea and Azotobacter was investigated for its impact on quality and biochemical attributes under protected cultivation. The findings revealed a noteworthy response of strawberry plants to foliar nano applications compared to conventional soil application of urea. Despite the lower nitrogen dosage associated with nanoparticle supplementation, strawberries with nanoparticles exhibited significant improvements in qualitative and biochemical parameters. These results underscore the potential of urea nanoparticles as a viable nitrogen source, advocating for alternative approaches to nitrogen fertilization. By fine-tuning the dosage ratio, this strategy shows promise in fostering a more environmentally friendly, sustainable and modern method for cultivating strawberries. The enhanced quality and biochemical attributes observed in strawberries treated with nano urea highlight the efficacy of this innovative approach in optimizing plant growth and productivity. Furthermore, the utilization of nano urea in combination with Azotobacter demonstrates synergistic effects, potentially enhancing nutrient uptake and utilization efficiency in plants. This holistic approach improves crop quality and reduces the environmental impact associated with traditional fertilization methods. In conclusion, the findings of this study support the adoption of urea nanoparticles as a valuable tool in strawberry cultivation, offering a pathway towards sustainable agricultural practices. Future research efforts should focus on optimizing application protocols and assessing long-term effects to fully exploit the potential of nano-based fertilizers for strawberry.

Construction of Greenhouse for Horticultural Cultivation with Soil Media and Hydroponics

Theneral background greenhouse technology is increasingly recognized as an efficient solution for sustainable agricultural practices, especially in regions with limited fertile land. Specific background In Kedungpeluk Village, where the majority of residents work as fish farmers, there are also unused and arid lands. These underutilized spaces provide an opportunity for greenhouse-based horticultural cultivation using soil media and hydroponic technology. Knowledge gap however, limited knowledge and infrastructure have prevented local farmers from effectively utilizing these lands for sustainable crop production. Aims this community engagement project aims to build and utilize a greenhouse system to cultivate horticultural plants, focusing on optimizing both soil and hydroponic methods. Results the project successfully transformed barren land into productive greenhouses that facilitate the growth of tomatoes, chilies, eggplants, pak choy, and water spinach. The greenhouse structure, designed with transparent roofing, enhances sunlight exposure, promoting optimal plant growth. Both soil and hydroponic methods showed potential for increasing crop yields, with soil cultivation being more flexible but requiring extra care for pests, while hydroponics provided faster results with minimal weed and pest interference. Novelty this project introduces a dual-method approach combining traditional soil cultivation with modern hydroponic technology in a controlled greenhouse environment. Implications the findings highlight that greenhouse farming is a viable, modern agricultural solution for rural communities, offering increased productivity and quality crops, while also addressing the challenges of limited fertile land and changing climate conditions. This project serves as a model for sustainable agriculture in similar settings. Highlights: Dual-method approach: Combining soil and hydroponic techniques in a greenhouse. Efficient land use: Transforming unused arid land for productive horticulture. Controlled environment: Optimizing plant growth through sunlight, temperature, and humidity control. Keywords: Greenhouse, Horticulture, Soil Media, Hydroponics, Sustainable Agriculture

Growth, Ecophysiological Responses, and Leaf Mineral Composition of Lettuce and Curly Endive in Hydroponic and Aquaponic Systems.

Against the backdrop of climate change, soil loss, and water scarcity, sustainable food production is a pivotal challenge for humanity. As the global population grows and urbanization intensifies, innovative agricultural methods are crucial to meet rising food demand, while mitigating environmental degradation. Hydroponic and aquaponic systems, has emerged as one of these solutions by minimizing land use, reducing water consumption, and enabling year-round crop production in urban areas. This study aimed at assessing the yield, ecophysiological performance, and nutritional content of Lactuca sativa L. and Cichorium endivia L. var. crispum grown in hydroponic and aquaponic floating raft systems, with Oreochromis niloticus L. integrated into the aquaponic system. Both species exhibited higher fresh biomass and canopy/root ratios in hydroponics compared to aquaponics. Additionally, hydroponics increased the leaf number in curly endive by 18%. Ecophysiological parameters, such as the leaf net photosynthesis rate, actual yield of PSII, and linear electron transport rate, were also higher in hydroponics for both species. However, the nutritional profiles varied between the two cultivation systems and between the two species. Given that standard fish feed often lacks sufficient potassium levels for optimal plant growth, potassium supplementation could be a viable strategy to enhance plant development in aquaponic systems. In conclusion, although aquaponic systems may demonstrate lower productivity compared to hydroponics, they offer a more sustainable and potentially healthier product with fewer harmful compounds due to the reduced use of synthetic fertilizers, pesticides, and the absence of chemical residue accumulation. However, careful system management and monitoring are crucial to minimize potential contaminants.

Partial replacement of inorganic fertilizer with organic inputs for enhanced nitrogen use efficiency, grain yield, and decreased nitrogen losses under rice-based systems of mid-latitudes

In the rice-based system of mid-latitudes, mineral nitrogen (N) fertilizer serves as the largest source of the N cycle due to an insufficient supply of N from organic sources causing higher N losses due to varying soil and environmental factors. However, aiming to improve soil organic matter (OM) and nutrients availability using the best environmentally, socially, and economically sustainable cultural and agronomic management practices are necessary. This study aimed to enhance nitrogen use efficiency (NUE) and grain yield in rice-based systems of mid-latitudes by partially replacing inorganic N fertilizer with organic inputs. A randomized complete block design (RCBD) was employed to evaluate the effects of sole mineral N fertilizer (urea) and its combinations with organic sources—farmyard manure (FYM) and poultry compost—on different elite green super rice (GSR) genotypes and were named as NUYT-1, NUYT-2, NUYT-3, NUYT-4, NUYT-5, and NUYT-6. The study was conducted during the 2022 and 2023 rice growing seasons at the Rice Research Program, Crop Sciences Institute (CSI), National Agricultural Research Centre (NARC), Islamabad, one of the mid-latitudes of Pakistan. The key objective was to determine the most effective N management strategy for optimizing plant growth, N content in soil and plants, and overall crop productivity. The results revealed that the combined application of poultry compost and mineral urea significantly enhanced soil and leaf N content (1.36 g kg− 1 and 3.06 mg cm− 2, respectively) and plant morphophysiological traits compared to sole urea application. Maximum shoot dry weight (SDW) and root dry weight (RDW) were observed in compost-applied treatment with the values of 77.62 g hill− 1 and 8.36 g hill− 1, respectively. The two-year mean data indicated that applying 150 kg N ha⁻1, with half provided by organic sources (10 tons ha⁻1 FYM or poultry compost) and the remainder by mineral urea, resulted in the highest N uptake, utilization, and plant productivity. Thus, integrated management of organic carbon sources and inorganic fertilizers may sustain the productivity of rice-based systems more eco-efficiently. Further research is recommended to explore root and shoot morphophysiological, molecular, and biochemical responses under varying N regimes, aiming to develop N-efficient rice varieties through advanced breeding programs.

Is Tea Waste A Promising Co-substrate for Optimizing The Cultivation, Growth, and Yield of Charleston Pepper (Capsicum annuum L.)?

To address growing concerns about sustainable agriculture and waste management, this study aimed to explore the viability of tea waste as an eco-friendly alternative substrate for cultivating Charleston peppers (Capsicum annuum), with the goal of optimizing plant growth and yield while reducing soil dependence, lowering cultivation costs, and repurposing agro-industrial waste. Six different substrate combinations were evaluated: 1) Tea waste, 2) Tea waste + Manure, 3) Tea waste + Soil, 4) Manure + Soil, 5) Tea waste + Manure + Soil, and 6) Tea waste + Manure + Soil + Perlite. Data were analyzed using both multivariate and univariate analyses to assess significant differences among treatments. Notably, significant differences in stem diameter were observed among plants grown on different substrates (one-way MANOVA, p <.05). However, plant height and chlorophyll content remained unaffected by substrate type. Although leaf structure exhibited considerable variation across treatments, no significant difference in dry matter content was observed. These results demonstrate that tea waste, especially when combined with other materials, is a promising sustainable substrate for Charleston pepper cultivation, potentially reducing soil dependence and agro-industrial waste.

Multi-scale hybrid modeling of plant growth in response to environmental conditions and soil nutrients availability

Crop modeling plays a crucial role in agriculture, aiding our understanding and prediction of crop growth and yield in diverse environmental conditions. This study aims to develop a comprehensive mathematical model describing plant growth in response to environmental conditions and soil nutrient availability. To achieve this, we relied on a field experiment with lettuce plants under varying environmental conditions. Employing growth models such as logistic, Gompertz, Aikman & Scaife, and Scaife, Cox & Morris, we assessed the influence of time, day-degrees, and effective-day-degrees across different plant densities and during distinct periods throughout the year. In general, describing plant growth in terms of day-degrees or effective-day-degrees yielded an improved model fit and more precise estimations of growth parameters. As a result, we described the growth of plant length in terms of effective-day-degrees instead of time in the equations of the Bessonov-Volpert system. Additionally, we modified the equation describing plant length growth using previously fitted functions. By incorporating these adjustments, we characterized the one-dimensional growth of plant weight under varying environmental conditions without branching, using the Bessonov-Volpert model. This study contributes valuable insights into crop modeling techniques, refining our understanding of optimizing plant growth under different environmental conditions.

Efficient Plantlet Regeneration from Branches in Mangifera indica L.

Mango (Mangifera indica L.) is one of the most significant tropical and subtropical fruit species, with high ecological and economic value. However, research on the in vitro culture of mangoes is relatively weak, so establishing an efficient and stable mango plant regeneration system is of great significance. In this study, a preliminary mango regeneration system was established with Mangifera indica L. cv. Keitt from young branches as the starting explants. The results showed that the optimal plant growth regulator (PGR) formula for direct adventitious shoot induction on the branches was 1 mg/L 6-benzylaminopurine (6-BA) + 0.1 mg/L a-naphthaleneacetic acid (NAA), with an adventitious shoot induction rate of 73.63% and an average of 6.76 adventitious shoots. The optimal basal medium for adventitious shoot induction was wood plant medium (WPM), with an adventitious shoot induction rate of 63.87% and an average of 5.21 adventitious shoots. The optimal culture medium for adventitious shoot elongation was WPM + 1 mg/L 6-BA + 0.5 mg/L NAA, with an adventitious shoot elongation rate of 89.33% and an average length of 5.17 cm. The optimal formula for the induction of mango rooting was Douglas fir cotyledon revised medium (DCR) + 3 mg/L indole-3-butyric acid (IBA), with a maximum rooting rate of 66.13% and an average rooting quantity of 6.43. The genetic fidelity of the in vitro-regenerated plants was evaluated using inter-simple sequence repeat (ISSR) molecular markers. There was no difference between the in vitro-regenerated plants and the parent plant. This study provides an efficient and stable propagation system for Mangifera indica L., laying the foundation for its rapid propagation and genetic improvement.

Automated vs. Semi-Automated Hydroponics

The issue of hydroponic farming is the ongoing requirement to maintain and control the artificial growing environment to enable optimal plant growth. The quality of the plants growing on the farm can be significantly impacted by changes in the climate, natural light, and fertilizer solution at any time during the plant's growth cycle. According to studies, every 3°C increase in ambient temperature from the optimal range reduces crop productivity by 10 to 40%. Therefore, by automatically supplying ideal growth conditions throughout the growing cycle, IoT-based automation is crucial to achieving optimal plant growth. In this work, lettuce is grown simultaneously in two distinct hydroponic Nutrient Film Technique (NFT) systems, one of which is fully automated and the other semi-automated. In terms of plant growth metrics, such as plant elevation, maximum plant length, maximum plant breadth, and weight of both fresh and dry-farmed lettuce, this paper compared a fully automated farm and a semi-automated NFT farm for growing lettuce. The outcomes demonstrate that the ariel weight of fresh and dry lettuce and root weight of fresh and dry lettuce had average improvements of 10.4 gm, 0.7 gm, 0.11 gm, 0.7 gm, and 3, respectively in the fully automated setup. Findings also demonstrated that IoT-based automation enhances the growth of lettuce plants on farms when comparing a completely automatic hydroponic farm to a semi-automatic hydroponic farm, in terms of plant height, width, and total leaf count.

Evaluating the Efficacy of Selected Plant Growth-Promoting Microorganisms in Optimizing Plant Growth and Soil Health in Diverse Soil Types

Evaluating the Efficacy of Selected Plant Growth-Promoting Microorganisms in Optimizing Plant Growth and Soil Health in Diverse Soil Types

Constitutive BoHAK5 expression and early robust induction of salicylic acid biosynthesis genes as candidates to explain the tolerance of broccoli to limiting potassium

Potassium (K+) is vital for optimum plant growth and crop yield, and it is an important component of fertilizers. However, our knowledge of the physiological and molecular response to limiting K+ conditions is incomplete. Despite their close phylogenetic relationship, we observed that broccoli is more tolerant to limiting K+ conditions than Arabidopsis. For this reason, we performed a detailed physiological and transcriptomic analysis to compare and contrast their response to this abiotic stress. Our results show that the K+ content of broccoli roots decreases at a slower rate than Arabidopsis. Both species exhibited characteristic responses observed in other plants, such as those related to oxidative stress, hypoxia and jasmonic and abscisic acid signaling. However, we observed notable differences in their responses, especially in the expression of BoHAK5 and the early and strong induction of isoforms of salicylic acid (SA) biosynthesis genes in broccoli, which was reflected in the increased SA accumulation in broccoli leaves. We also observed alterations in the gene expression patterns of enzymes and in the levels of intermediates involved in the biosynthesis of glucosinolates, which are important molecules contributing to the added nutritional value of broccoli. Lastly, we provide evidence for concomitant alterations in the expression patterns of genes encoding transporters of several other ions, such as Fe2+, PO43− and NO3−. Our data provide insight into the possible mechanisms of broccoli’s tolerance to limiting K+ conditions and identify specific targets for the development of crop plants with reduced fertilization requirements.

Artificial intelligence can regulate light and climate systems to reduce energy use in plant factories and support sustainable food production.

Plant factories with artificial lighting (PFALs) can boost food production per unit area but require resources such as carbon dioxide and energy to maintain optimal plant growth conditions. Here we use computational modelling and artificial intelligence (AI) to examine plant-environment interactions across ten diverse global locations with distinct climates. AI reduces energy use by optimizing lighting and climate regulation systems, with energy use in PFALs ranging from 6.42 kWh kg-1 in cooler climates to 7.26 kWh kg-1 in warmer climates, compared to 9.5-10.5 kWh kg-1 in PFALs using existing, non-AI-based technology. Outdoor temperatures between 0 °C and 25 °C favour ventilation-related energy use reduction, with outdoor humidity showing no clear pattern or effect on energy use. Ventilation-related energy savings negatively impact other resource utilization such as carbon dioxide use. AI can substantially enhance energy savings in PFALs and support sustainable food production.

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.

Impact of Smart Greenhouse Using IoT for Enhanced Quality of Plant Growth

Greenhouses play a crucial role in manipulating environmental conditions for optimal plant growth. While existing greenhouses enhance control over environmental factors, manual controls such as watering and humidity regulation often lead to suboptimal production and increased costs. This study proposes the development of a smart greenhouse with an automatic control system using fuzzy logic, specifically fuzzy Sugeno, to regulate watering and lighting based on soil moisture, temperature, and light intensity. The system's architecture involves sensor inputs, microcontroller processing, and the activation of actuators, such as UV lights and water pumps. Fuzzy logic is applied to interpret soil moisture and temperature inputs and determine optimal irrigation durations. The system's functionality is tested and validated through functional testing, Blynk application testing, and fuzzy Sugeno testing. Results indicate the successful implementation of the proposed smart greenhouse system. Functional testing demonstrates accurate sensor readings, including temperature and soil moisture. The Blynk application enables real-time monitoring and control of environmental conditions. Fuzzy Sugeno testing validates the irrigation control system, with an average error rate of 1.3%, affirming the system's alignment with desired specifications. Plant testing in different conditions showcases the effectiveness of the smart greenhouse in supporting plant growth and development.

Molecular characterization and validation of zinc solubilization potential of bacteria isolated from onion (Allium cepa L.) rhizosphere

Zinc (Zn) is essential for optimal plant growth and nutrition, while zinc-solubilizing bacteria (ZSB) enhance plant accessibility to zinc by converting its insoluble forms into usable ones. The primary objective of this research was to isolate and identify Zn-solubilizing strains from the onion rhizosphere and evaluate their ability to solubilize different insoluble Zn compounds, including ZnO, ZnCO3, and Zn3(PO4)2. Of the nineteen bacterial isolates retrieved, fifteen demonstrated the ability to solubilize inorganic Zn compounds based on plate assay techniques. The Zn-solubilizing bacterial strains, selected for their qualitative properties, underwent quantitative testing in broth culture using atomic absorption spectrophotometry (AAS) and Field Emission-Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (FE-SEM-EDS). Seven bacterial isolates with a high capacity to solubilize Zn were identified based on 16S rRNA gene amplification and sequence analysis. These isolates were affiliated with Pantoea eucrina, Pantoea dispersa, Pseudomonas aeruginosa, Bacillus velezensis, and Pseudomonas fluorescens. Notably, this study is the first to report the potential of Pantoea eucrina as a ZSB. The strain Pantoea eucrina ZSC9 exhibited the maximum Zn solubilization index (8.85) and the highest soluble Zn content (624 mg L−1) among the three insoluble Zn compounds, with ZnO being the most effectively solubilized on the 10th day of incubation in ZnO-enriched basal medium. All bacterial isolates were more effective at solubilizing ZnO than ZnCO3 and Zn3(PO4)2, and this solubilization led to a significant drop in the pH of the broth. Pantoea eucrina ZSC9 showed the maximum pH reduction (3.82) in a ZnO-supplemented medium, indicating a negative correlation between broth pH and Zn solubilization. Seven selected ZSB strains were assessed for their potential to enhance onion growth under pot house conditions. The results showed that inoculating onion seedlings with these ZSB strains significantly improved their growth. Among the strains tested, ZSC9, ZSC10, and ZSC17 were the most effective, enhancing growth attributes such as plant height, bulb diameter, fresh and dry weight of bulbs, Zn uptake by the plant, and overall bulb yield compared to other strains. These findings suggest that these ZSB isolates have great potential as biofertilizers to enhance plant growth and development.

Nutrient Dynamics and Resource-Use Efficiency in Greenhouse Strawberries: Effects of Control Variables in Closed-Loop Hydroponics

The importance of implementing recirculating drainage for greenhouse strawberries is often overlooked because of the low electrical conductivity (EC) of drainage and transpiration despite the large area of cultivation in Korea. In this study, we analyzed the growth of strawberry crops and their water and individual nutrient use efficiency when using closed-loop hydroponics in greenhouses. The study consisted of two parts: Experiment (Exp) 1 and Exp 2, each of which employed a different closed-loop hydroponic control method. In Exp 1, the system was controlled solely based on the EC of the drainage mixed with raw water. In Exp 2, the nutrient solution (NS) was corrected according to the ion concentrations in the drainage, with correction intervals of 2 weeks, 4 weeks, and no correction, while the control treatment was open-loop. In Exp 1, a prolonged increase in drainage EC resulted in an imbalance in NS ion composition and reduced fruit yield. In Exp 2, the NS composition was stabilized through periodic nutrient correction, and the fruit yield of the closed-loop treatments did not differ from the open-loop treatment. However, the closed-loop with 2- and 4-week correction in Exp 2 showed 94% and 88% higher nutrient use efficiency (NUE), respectively, than an open-loop system. Among the closed-loop treatments, the 2- and 4-week correction intervals had 36% and 32% higher NUE than the no-correction treatment. Furthermore, the 2-week correction interval showed a 3% improvement in NUE compared to the 4-week interval. These findings highlight the importance of considering a shorter ion correction interval for optimal NUE and normal plant growth in recirculating hydroponic systems of strawberry cultivation.

Development of Smart Hydroponics System using AI-based Sensing

This paper proposes a smart hydroponic system that operates automatically using a fuzzy logic algorithm, integrating IoT functionalities to support smart agriculture. The system allows for remote monitoring and control via the internet, providing real-time data on water levels, pH levels, temperature, and nutrient solution temperature. Precise dosing and temperature control are critical for optimal plant growth, and the system schedules temperature measurements to ensure stability. Unstable temperature can affect pH levels, thereby impacting nutrient absorption. The proposed system employs sensors to continuously monitor the electrical conductivity (EC) and pH levels of the nutrient solution. Fuzzy control is utilized to regulate the nutrient solution pump, automatically adjusting EC and pH levels to promote optimal plant growth. This approach reduces the time burden on producers and provides more precise control over the nutrient solution, resulting in improved growth outcomes. The main contributions of this work are as follows: the development and implementation of an AI-based system integrating a controller, IoT environment, fuzzy logic algorithm, and NFT (nutrient film technology) hydroponics; the creation of a user-friendly interface for farmers through the Smart-Hydroponic application, enabling hybrid monitoring and control of hydroponic farms; the establishment of an IoT-based cloud environment for sensor data monitoring; the implementation of a smart hydroponic system for nutrient sensing, monitoring, and control; and a comparative analysis between smart and conventional hydroponics based on morphological results.