Small Scale Research Articles

Effect of a perforation on the flow characteristics of corrugated wall

The flow characteristics on a corrugated wall and the variations caused by a perforation are investigated experimentally based on two-dimensional particle image velocimetry (PIV), and the passive control mechanism of the perforation on the corrugated wall is studied. The corrugated wall has an amplitude-to-wavelength ratio 2a/λ = 0.1, with the wavelength Reynolds number Reλ = 14400 and bulk Reynolds number Reb = 17500. The perforation is located on the eleventh cycle of the corrugated wall. The results show that perforation increases the area of the recirculation zone, reduces the effect of frictional resistance, weakens the turbulence intensity and the Reynolds normal stress on the corrugated wall, but enhances the Reynolds shear stress. The POD and the Finite-Time Lyapunov Exponent(FTLE) are used to analyze the vortex structures. From the FTLE result, it can be seen that the perforation disturbs the original shear layer and redistributes the vortex structure of the flow field. The instantaneous fluctuating flow field of the first 50 % and the last 50 % of the energy content after POD mode decomposition is reconstructed to study the effect of perforation on on large and small scale structures in the flow field. It is found that the impact of perforation on small-scale structures is greater than that on large-scale structures.

Nonlinear saturation of the ion flow driven ion sound instability in a finite length plasma

The saturation mechanism and nonlinear evolution of the ion sound instability driven by the subsonic ion flow in a finite length plasma are studied by a one-dimensional hybrid model considering kinetic ions and Boltzmann electrons. Three regimes of the instability nonlinear behavior are identified as a function of the frequency of the ion-neutral charge exchange (CX) collision fcoll. In the first (collisionless-alike) regime when the CX frequency is low, the instability is saturated by ions trapping in wave potentials leading to the formation of phase space vortexes (PSVs). One of the PSVs subsequently expands and becomes system long in the steady state. The transition to the second (medium) regime occurs when fcoll≳vp/d, where vp is the PSV expansion velocity and d is the system length. In the second regime, CX collisions convert fraction of beam ions into slow ions that can be trapped in potentials of small scale ion sound eigenmodes fluctuations. The trapping of slow ions results in the formation of a chain of small scale PSVs and the disruption of the establishment of the single system long PSV. In the third (collision-dominated) regime when fcoll≳γ (γ is the instability growth rate), CX collisions transform all beam ions into slow ions and the instability is thereby eliminated.

Case Study Analysis on the Flood Mitigation Effects of Improving a Drainage System Using Low Impact Development Techniques

Low-impact development (LID) techniques aim to minimize the hydrological and environmental impacts associated with watershed development by preserving the natural state as much as possible, reducing impervious surfaces, managing stormwater on a small scale at the point of generation, and promoting decentralized stormwater management. In this study, the flood reduction effects of LID techniques were analyzed using PCSWMM by comparing traditional development methods in the Songsan Green City development project. In this process, the LID technique considers nonstructural methods of diversifying drainage directions and structural methods of introducing vegetated swales to improve the drainage system. The results showed that the LID approach, introduced to improve the drainage system, had a significant effect on reducing floods and inundation compared to traditional development methods. The results of this study suggest the potential of using LID techniques in structural and nonstructural approaches to improve urban flooding and inundation problems.

Artificial intelligence: how have Learning Developers engaged?

The ALDinHE Artificial Intelligence (AI) Community of Practice (CoP) was established in the summer of 2023. It has an international membership of over 200 Learning Developers. The CoP meets monthly to discuss an AI-related topic. Since its inception, topics have included organisational approaches to AI, AI in assessment, maths and statistics, and the use of AI in Learning Development tutorials. The group is keen to create an opportunity to share current projects, approaches, and thinking. This wildcard session replicated a world café-style event on a smaller scale. It required a large room. Tables were hosted by colleagues from Abertay University, Bournemouth University, De Montfort University, the University of Manchester, the University of Northampton, and Spurgeon’s College. Each host led a 15-minute session, sharing their AI-related project with delegates seated around the table, which included a short presentation followed by an opportunity for delegates to share their views and exchange ideas. After 15 minutes, the delegates moved to another table. Within the hour, the delegates rotated around three tables. It was hoped that delegates would attend the session to expand their understanding of AI. Delegates who use AI in their day-to-day work had an opportunity to share their experiences, while delegates who were less experienced could expand their understanding and discuss with their peers the challenges and opportunities that AI brings to Learning Development.

버나놀이를 활용한 초등 국악 수업의 연구와 실제

This study aims to help students understand the emotions embedded in Korean music and appreciate the intrinsic values of cultural arts by engaging them in specific activities and diverse experiences through gugak classes. To achieve this, an on-site research lesson utilizing beona-nori (a game of spinning with beona) from cultural heritage included in elementary school textbooks was conducted. The study proposes results and instructional strategies to facilitate the meaningful application of beona-nori in future lessons. Traditional Korean games are composed of songs, dances, and various tools, making them accessible to people of all ages. This broad applicability suggests that their integration into elementary education is highly feasible. Among these games, beona-nori is particularly suitable for elementary gugak education as it can stimulate students' interest and provide rich sensory experiences through its use as a cultural and artistic educational tool. However, it has been observed that many teachers still find gugak challenging. They often feel unsure about teaching it or perceive the content itself as difficult. Therefore, exploring various methods that enable teachers to actively engage with students through play is essential. Field-based research, in particular, captures practical examples of gugak classes, thus reducing the burden of lesson planning and offering direct assistance in applying these methods effectively. This study was conducted with 24 fifth-grade students at H Elementary School in Gyeonggi Province. Given that this research was conducted in an elementary school setting, the proposed teaching methods are deemed feasible for implementation, considering the context of each school. However, given the small scale of the study, generalizing the findings may be challenging.

Study on Crushed-Stone Cementation Properties and Bottom Stope Stability of Goaf by Open Stope Mining in Inclined Ore Bodies

The mining of the part of the inclined ore body below a goaf is crucial for improving resource extraction and safe production. In this study, the cementation properties of crushed stone during the mining of the inclined ore body were investigated by means of laboratory experiments, theoretical analysis, and numerical simulation. Additionally, orthogonal experiments were performed to assess how factors like water–cement ratio, crushed-stone particle size, and cement–sand ratio affect the strength of the grouting concretion body (GCB). Furthermore, the fluidity of the slurry under different ratios was also measured. Considering both the fluidity of the slurry and the strength of the GCB, the optimal ratios of the slurry were determined to be a water–cement ratio of 2.5:1 and a cement–sand ratio of 1:4. This ratio was then used for crushed-stone cementing under the poorest crushed-stone particle size conditions, based on which mechanical parameters were obtained from experiments. Theoretical analysis equated the problem of the grouting range to the width of the plastic zone of surrounding rock, and a conclusion was reached that the width of the GCB should be at least 29 m. The numerical simulation results reveal that among 30 mining rooms formed below the GCB, 24 mining rooms are in a stable state and 6 mining rooms are partially damaged on a small scale. As a whole, the GCB formed by grout filling into the goaf manages to effectively support the stope below, and it is verified that the theoretical calculation method of the width of the GCB is feasible.

Mechanisms Underlying Sensory Nerve-Predominant Damage by Methylmercury in the Peripheral Nervous System.

Sensory disturbances and central nervous system symptoms are important in patients with Minamata disease. In the peripheral nervous system of these patients, motor nerves are not strongly injured, whereas sensory nerves are predominantly affected. In this study, we investigated the mechanisms underlying the sensory-predominant impairment of the peripheral nervous system caused by methylmercury. We found that the types of cell death in rat dorsal root ganglion (DRG) neurons caused by methylmercury included apoptosis, necrosis, and necroptosis. Methylmercury induced apoptosis in cultured rat DRG neurons but not in anterior horn neurons or Schwann cells. Additionally, methylmercury activated both caspase 8 and caspase 3 in DRG neurons. It increased the expression of tumor necrosis factor (TNF) receptor-1 and the phosphorylation of receptor-interacting protein kinase 3 (RIP3) and mixed-lineage kinase domain-like pseudokinase (MLKL). The expression of TNF-α was increased in macrophage-like RAW264.7 cells by methylmercury. The increase was suggested to be mediated by the NF-κB pathway. Moreover, methylmercury induced neurological symptoms, evaluated by a hindlimb extension response, were significantly less severe in TNF-α knockout mice. Based on these results and our previous studies, we propose the following hypothesis regarding the pathogenesis of sensory nerve-predominant damage by methylmercury: First, methylmercury accumulates within sensory nerve neurons and initiates cell death mechanisms, such as apoptosis, on a small scale. Second, cell death triggers the infiltration of macrophages into the sensory fibers. Third, the macrophages are stimulated by methylmercury and secrete TNF-α through the NF-κB pathway. Fourth, TNF-α induces cell death mechanisms, including necrosis, apoptosis through the caspase 8/3 pathway, and necroptosis through the TNFR1-RIP1-RIP3-MLKL pathway, activated by methylmercury in sensory neurons. Consequently, methylmercury exhibits potent cytotoxicity specific to the DRG/sensory nerve cells in the peripheral nervous system. This chain of events caused by methylmercury may contribute to sensory disturbances in patients with Minamata disease.

How Do Primordial Black Holes Change the Halo Mass Function and Structure?

We examine the effects of massive primordial black holes (PBHs) on cosmic structure formation, employing both a semianalytical approach and cosmological simulations. Our simulations incorporate PBHs with a monochromatic mass distribution centered around 106 M ⊙, constituting a fraction of 10−2 to 10−4 of the dark matter (DM) in the Universe, with the remainder being collisionless particle DM. Additionally, we conduct a ΛCDM simulation for comparative analysis with runs that include PBHs. At smaller scales, halos containing PBHs exhibit similar density and velocity dispersion profiles to those without PBHs. Conversely, at larger scales, PBHs can expedite the formation of massive halos and reside at their centers owing to the “seed effect.” To analyze the relative distribution of PBH host halos compared to non-PBH halos, we apply nearest neighbor statistics. Our results suggest that PBH host halos, through gravitational influence, significantly impact the structure formation process, compared to the ΛCDM case, by attracting and engulfing nearby newly formed minihalos. Should PBHs constitute a fraction of DM significantly larger than ∼10−3, almost all newly formed halos will be absorbed by PBH-seeded halos. Consequently, our simulations predict a bimodal feature in the halo mass function, with most of the massive halos containing at least one PBH at their core and the rest being less massive non-PBH halos.

Solar Wind Turbulence and Complexity Probed with Rank-Ordered Multifractal Analysis (ROMA)

The Rank-Ordered Multifractal Analysis (ROMA) is a tool designed to characterize scale (in)variance and multifractality based on rank ordering the fluctuations in “groups” characterized by the same mono-fractal behavior (Hurst exponent). A range-limited structure-function analysis provides the mono-fractal index for each rank-ordered range of fluctuations. We discuss here two examples of multi-scale solar wind turbulence and complexity where ROMA is applied on the following: (a) data collected by Ulysses spacecraft in the fast solar wind, outside the ecliptic, between 25 and 31 January 2007, at roughly 2.5 Astronomical Units (AU) from the Sun, in the Southern heliosphere, at latitudes between −76.5 and −77.3 degrees, and (b) slow solar wind data collected in the ecliptic plane by Venus Express spacecraft, at 0.72 AU, on 28 January 2007. The ROMA spectrum of fast solar wind derived from ULYSSES data shows a scale-dependent structure of fluctuations: (1) at the smallest/kinetic range of scales (800 to 3200 km), persistent fluctuations are dominant, and (2) at the inertial range of scales (104 to 2 × 105 km), anti-persistent fluctuations are dominant, but less clearly developed and possibly indicative for the development of instabilities with cross-over behavior. The ROMA spectrum of the slow solar wind derived from Venus Express data, suggests a different structure of turbulence: (1) fully developed multifractal turbulence across scales between 5 × 104 and 4 × 105 km, with the Hurst index changing from anti-persistent to persistent values for the larger amplitude magnetic fluctuations; (2) at the smallest scales (400 to 6400 km), fluctuations are mainly anti-persistent, and the ROMA spectrum indicates a tendency towards mono-fractal behavior.

SMEs’ dependency on large corporations’ technology for sustainability in the United States

Introduction/Background: This study discusses how small and medium-sized firms (SMEs) depend on major corporations for key technology resources that support sustainability initiatives. While SMEs contribute considerably to economic development and innovation, they typically rely on bigger enterprises for access to new technology and market possibilities. This partnership gives SMEs benefits like greater operational efficiency and global market access but also creates obstacles such as budgetary limits and technical reliance. The essay explores techniques for SMEs to effectively exploit new technologies, balancing partnership with larger firms while retaining their autonomy and competitiveness in a quickly shifting business climate focused on sustainability. Materials and Methods: The materials used for this study were sourced from different databases which include scholarly journal articles, reports, and government gazette and policy papers in the areas of business, small and medium scale enterprises, entrepreneurship, management and economics. The inclusive criteria ensured that only those articles that investigated the merits and demerits of SMEs dependence on large corporation were utilised. The review of literature was conducted on 50 documents published between 2009 and 2024. Results: The findings as revealed from the reviewed literature revealed the different merits and demerits of SMEs dependence on large corporation. Case studies of Tesla, Microsoft, Walmart, and Amazon demonstrate the intricate reliance of SMEs on major firms in the United States. Tesla's reliance on SMEs for crucial components like batteries underlines the reciprocal advantages and dangers involved, since SMEs' stability rests on Tesla's performance. Microsoft helps SMEs through initiatives that stimulate innovation and technology adoption, boosting their capabilities. Walmart gives SMEs with access to huge distribution networks, enabling sales growth. Similarly, Amazon's platform gives SMEs tremendous market reach but also brings issues in competitiveness and price. Together, these instances show the potential and challenges SMEs confront in their relationships with bigger enterprises. Discussion: Encouraging supplier growth and enhancing supply chain resilience are vital for establishing a sustainable SME environment. Policymakers may promote SMEs through mentorship programs, financial aid, and tax incentives for partnership with large enterprises. Addressing financial impediments with targeted funding and boosting skills development through collaborations with educational institutions would help SMEs embrace new technology. Additionally, establishing technology-sharing activities and developing a legal framework that supports fair competition are vital. Fostering innovation among SMEs and supporting sustainable practices will eventually boost their competitiveness and contribute to broader economic and environmental goals, benefitting both SMEs and bigger organizations. Conclusion: The reliance of SMEs on big corporations provides noteworthy hurdles and possibilities that require for the adoption of effective government involvement. Through the elimination of financial obstacles, the upgrading of technical skills, the promotion of fair competition, and the encouragement of innovation and sustainability, governments may build a fair climate that enables SMEs to prosper alongside bigger firms. This approach not only allows SMEs access to resources and contemporary technology, but it also stimulates economic variety and creativity, which in turn contributes to continuous development and competitiveness in a dynamic market.

The role and value of professional membership for emergency nurses: What are the key elements?

Granovetter (1973) wrote on the ‘Strength of Weak Ties’, even though published all those years ago, there was value and recognition placed on the strength of smaller group interactions and how they can impact on more macro level patterns, the same sociological theory holds true today. There are strengths in professional memberships, whether they are conducted on a small or large scale. They are powerful vessels for nurses to have impactful interactions. We recognize that professional memberships for nursing are available globally, whether that is through a local, national, or international organization. They offer a broad range of opportunities including education, bursaries, conferences, networking, and leadership opportunities. They are seen to connect and engage with peers and in some countries professional organizations also drive change, politically lobby, or even offer professional indemnity insurance or union support. Despite a strong presence in nursing professional organizations, the evidence shows that membership is declining or staying stagnant, and it is growing more difficult to bring nurses together through these channels. So, the question must be asked, ‘Why do nurses not strongly engage with professional organizations?’ This study focuses on emergency nurses to gain a greater understanding of drivers for professional membership and engagement.

Performance Evaluation of a Power Rotary Slicing Machine

This paper presents the performance evaluation of a power operated rotary slicer capable of slicing plantain, cocoyam, cassava among others. The machine is designed and fabricated to aid production of chips in plantain, cassava, cocoyam and other related farm products for frying and as well drying for immediate consumption and storage purposes. The machine is made up of two blades cutter and operated at speed of 1440rpm to overcome drawbacks of existing hands or power operated slicer and to meet the demand of small scale processing industries. Samples was taken for plantain, cocoyam and cassava to evaluate the efficiency and capacity of the machine. The machine has 83% efficiency and capable of producing 22.9kg/h.

ENERGY EFFICIENT ROUTING PROTOCOL FOR SECURITY ANALYSIS SCHEME USING HOMOMORPHIC ENCRYPTION

Wireless Sensor Networks (WSNs) have gained widespread interest as a result of developments in IT technology and the electronics industry. This ground-breaking sensing technology consists of multiple sensor nodes or motes that are placed in an atmosphere to detect constantly changing physical phenomena. These compact sensor nodes gather and interpret data via radio waves. The tiny size of these sensors is advantageous since they may be readily incorporated into any system or system. This capability has prompted the adoption of WSNs, particularly for form monitoring and tracking; most notably, monitoring apps. However, this small scale of sensor nodes limits the capacity of resources. Usually, the WSNs are installed in environments of unsafe or difficult human interference. Critical decisions in emergency applications can require sensible knowledge. It is necessary to check the network security. To extend the network security using Homomorphic Encryption effectively, the available resources must be expanded to a full view. This refers to the development of energy-efficient routing protocol strategies to ensure low energy consumption of common routing protocols and improve the availability and security of WSNs. Homomorphic encryption is effective in improving the security of wireless sensor networks.

Updated state of small scale fisheries on the Romanian Black Sea area

Romanian small-scale fisheries are practiced along the Black Sea coast in five fishing ports (Sulina, Cape Midia, Tomis, Constanta and Mangalia) and 18 other small fishing stations, located between Sulina - Vama Veche, at depths ranging between 2 - 20 m and sometimes up to 50 m, when practicing specialized turbot fisheries. Of significant importance is fishing with divers for the Rapana venosa, the species with the greatest impact on the landed catches. In the coastal area, between Vama Veche and Sulina, which also represents an important area for the reproduction, feeding and rearing of some important fish species, the small-scale fishing is practiced with fixed and active gear, throughout the year, mainly using the following types of fishing gears: pound nets, gillnets, longlines, beach seines, cages/traps, handlines and from 2013 with beam trawl. Catch and fishery productivity vary yearly, depending on environmental conditions, fishing effort, status of main commercial species, and human factors. During the analyzed period (2019 - 2023), catches in shallow waters were between 7149 and 3127 tons, which has an increasing trend compared to the previous period (2012 – 2017).

Continuous surface-to-distributed acoustic sensor snapshots explain reactivation of individual natural fractures during an unconventional reservoir stimulation

Fiber-optic sensing technologies allow petroleum engineering teams to detect hydraulic fracture interaction with boreholes during unconventional reservoir stimulation. In combination with high-repeatability seismic sources, the same distributed acoustic sensors (DASs) enable vertical seismic profiling (VSP) of the fracture evolution away from the boreholes. We discovered clear signatures of seismic scattering on activated fractures during nine days of continuous seismic monitoring of the fracturing stages at the Austin Chalk/Eagle Ford Field Laboratory. The present study applies a novel approach for quantitative analysis of the scattering events in terms of the evolution of the geometry and elastic stiffness of individual fractures. Our characterization strategy sequentially refines the fracture models: from a stack of 1D soft layers to 3D rectangular inclusions. First, we estimate the number of fracture locations and reflectivity using a modified sparse-spike deconvolution of the stacked VSP traces. The fracture set consists of five fractures spaced by 15–30 m with a reflectivity of approximately 1%. Then, we develop a scattering integral method to refine these estimates along with an inversion of the fracture top and bottom for each monitoring vintage. We find that, initially, some of the fractures are located above the monitoring fiber with the height of approximately 100 m. Then we integrate the seismic interpretation with the low-frequency DAS and pressure and microseismic monitoring to reconstruct the activation process of the fractures. Most likely, some of the natural fractures slowly grew downward to the monitoring fiber as a result of fluid injections in the stimulated well. This led to bright strain anomalies but did not trigger seismicity. The top of the fractures remained almost constant and were limited by a lithologic boundary/stress barrier. To our knowledge, this is the first time VSP data enabled tracking of the fracture evolution with such high spatial and temporal resolution, which was previously only available for crosswell surveys and at a much smaller scale.

Complexity and synchronization of carbon and new energy markets based on multiscale entropy

AbstractThis study provides a comprehensive analysis of the dynamic evolution of complexity and synchrony between the carbon market and the new energy market from 2019 to 2023, employing multiscale sample entropy and cross‐sample entropy methods. The study shows that, both in the long term and short term, the complexity of the new energy market consistently exceeds that of the carbon market. Additionally, the carbon and new energy markets exhibit higher synchronization on smaller scales. As the time scale increases, interactions between the carbon and new energy markets become more complex and diverse. According to these findings, it is recommended that policymakers improve the transparency of the new energy market, optimize the operational mechanisms of the carbon market, and ensure that carbon reduction strategies and new energy policies are mutually coordinated. This holds significant importance for both carbon reduction targets and the development of new energy.

New Insights into Type-I Solar Noise Storms from High Angular Resolution Spectroscopic Imaging with the Upgraded Giant Metrewave Radio Telescope

Type-I solar noise storms are perhaps the most commonly observed active radio emissions from the Sun at meter-wavelengths. Noise storms have a long-lived and wideband continuum background with superposed islands of much brighter narrowband and short-lived emissions, known as type-I bursts. There is a serious paucity of studies focusing on the morphology of these two types of emissions, primarily because of the belief that coronal scattering will always wash out any features at small angular scales. However, it is important to investigate their spatial structures in detail to make a spatio-temporal connection with observations at extreme-ultraviolet/X-ray bands to understand the detailed nature of these emissions. In this work, we use high angular resolution observations from the upgraded Giant Metrewave Radio Telescope to demonstrate that it is possible to detect structures with angular scales as small as ∼9″, about three times smaller than the smallest structure reported to date from noise storms. Our observations also suggest that while the individual type-I bursts are narrowband in nature, the bursts are probably caused by traveling disturbance(s) inducing magnetic reconnections at different coronal heights, and thus leading to correlated change in the morphology of the type-I bursts observed at a wide range of frequencies.

Variations of Heat Flux and Elastic Thickness of Mercury From 3‐D Thermal Evolution Modeling

AbstractMercury's low obliquity and 3:2 spin‐orbit resonance create a surface temperature distribution with large latitudinal and longitudinal variations. These propagate via thermal conduction through the thin silicate shell influencing the interior temperature distribution. We use 3‐D thermal evolution models to investigate the effects of lateral variations of surface temperature and crustal thickness on the surface and core‐mantle boundary (CMB) heat fluxes, and elastic thickness distribution. Surface temperature variations cause a long‐wavelength perturbation of the heat fluxes, as well as of the elastic lithosphere thickness, while variations in crustal thickness affect these quantities at small spatial scales. Like the surface temperature, the present‐day CMB heat flux pattern is characterized primarily by spherical harmonics of degrees two and four, which could affect dynamo generation. Placing robust constraints on the thermal evolution based on the available estimates of the age and thickness of the elastic lithosphere remains challenging due to their large uncertainties.

A comprehensive assessment of gold leaching wastewater through pollution and water quality indices. Case study: Small scale extraction facilities in the department of Caldas—Colombia

This study introduced a comprehensive methodology (the Six-Indices method for Water Pollution Assessment) to evaluate the quality of gold leaching effluents. Sampling was conducted for 14 months in small-scale gold mining facilities in the department of Caldas, Colombia. 23 physicochemical parameters were selected based on environmental regulations, standards of use for agricultural purposes and WHO recommendations. They covered general characteristics of effluents and critical inputs of the leaching process. 15 (pH, COD, TSS, CN−, Cl−, SO42−, S2−, Cd, Zn, Cu, Cr, Fe, Ni, Ag, and Pb) of them exceeded permissible limits. Multivariate statistical analysis (Person's correlation and hierarchical clustering analysis) and six Wastewater Quality Indices (WWQIs: Arithmetic Weighted Water Quality Index, WAWQI, Synthetic Pollution Index, SPI, Index of Water Pollution, WPI, Comprehensive Pollution Index, CPI, Heavy Metal Pollution Index, HPI, and Degree of Pollution, Cd) were used to comprehensively assess the effluent contamination. Key pollutant interactions (hydrocarbons & fats and oils, Zn & CN−, Cu & Cl−, as well as CN− & COD & SO42−) were revealed guiding targeted mitigation strategies. CN− and heavy metals were the main pollutants, posing serious environmental risks due to their high levels. The calculated HPI value was above the critical level of 100, indicating that the artisanal gold leaching operations in the studied area could be hazardous to human health. This study provides a starting point for developing effective and sustainable strategies to manage wastewater in mining regions in Colombia and other areas with similar mining practices.

Cost of Productions and Partial Budget Analysis of Coffee (<i>Coffea arabica</i> L.) Seedling Across Various Pot Sizes and Biochar-Based Media Preparations

Coffee cultivation mainly lies in the production of coffee seedlings with desirable characteristics under the recommended nursery management operations. Any improper handling made at early stage would remain to cause poor field performances. Biochar is considered as a soil conditioner and a carrier for plant nutrients, which improve the different soil functions, as an amendment to improve soil fertility, soil pH, available phosphorus, organic carbon, and water retention. The experiment was conducted to provide detail information on production costs and gross net profits of reduced sizes poly bag and biochar application used for coffee seedling production under small scale farmers. Biochar to topsoil blended at 1:3 ratio was found to increase (SVI) over the local and standard practice by 66.50% and 7.50%, respectively. Hence, combined effects of reduced pot size (13x19cm) with biochar mixed topsoil 1:3 noticed to significantly improve soil chemical conditions and growth response of coffee seedlings under nursery conditions at the study area. Besides, the result of simple partial budget analysis indicated the cost effectiveness with reduced polybag sizes as compared to the conventional pot sizes, especially for production, transportation and early stage field transplanting of quality coffee seedlings in large quantities. However, it is imperative to assess the effects of the present promising pot size and pot media treatments under field performance by considering growth, yield, and quality performances and profitability to smallholder coffee farmers over locations and year in the study area and other similar agro ecological zones in the country.