Initial Moisture Content Research Articles

Adsorption layer of complex oil components in organic-rich shale: A molecular dynamics simulation study

Shale oil is enriched in organic-rich shale, and its reservoir is mainly composed of micro-nano pore throats. The fluid adsorption layer in nano-confined channels complicates the fluid properties and transport patterns. In this study, equilibrium molecular dynamics was used to study the distribution states and diffusion patterns of complex oil components in organic matter represented by kerogen and four inorganic minerals represented by illite, quartz, calcite, and albite. The thickness and proportion of adsorption layers with different pores are quantitatively calculated. The adsorption capacity is in the following order: kerogen > illite > albite > calcite > quartz. According to the interaction energy, the adsorption stability of oil on surfaces with different pores is in the following order: illite > albite > calcite > kerogen > quartz, and the main forces of adsorption with different pores are obtained. With the increase in pore size, the proportion of light components in the adsorption layer increases, and the proportion of heavy components decreases. The oil components in quartz, calcite, and albite gradually desorb with the increase of pore size, while the oil components in illite are the opposite. The adsorption proportion of other components except for toluene in the kerogen pore increased. The diffusion rate of components in kerogen, quartz, and calcite is related to their relative atomic mass. The diffusion coefficient of components in illite is related to the polarity of components. The diffusion rate of components in small pore sizes of albite minerals is related to the polarity of components, and the diffusion rate of components in large pore sizes is related to the relative atomic mass of components. The effect of temperature and initial moisture content on pores is related to the type of pores.

A review of test Methods, issues and challenges of Large-Scale fire testing of concrete tunnel linings

This article provides a summary of substantial aspects pertaining to the design of concrete tunnel linings subjected to serious fire exposure. Compared to building fires, the air temperature rise of tunnel fires is more significant within a few minutes due to the confined space. This is of concern to tunnel designers as rapid temperature rise has shown to be a dominant factor in relation to concrete spalling. The dramatic European tunnel fires that occurred in 1999 and 2001 led to the development of new regulations and recommendations, including new guidelines recommended by the European Federation of National Associations Representing producers and applicators of specialist building products for Concrete (EFNARC 132F r3:2006) and Efectis R0695:2020. These regulations were intended to offer tunnel designers some scope on how to test for concrete spalling with particular focus on explosive spalling of concrete given that, in general, tunnels are at greater risk than other structures. This is principally due to the high heating rate and the high initial moisture content present. To date, full scale experimental works have been limited and not as extensive as those of small to medium scale unloaded specimens exposed to elevated temperatures. This paper summarizes recent research on large scale concrete tunnel lining tests exposed to fire conditions. The methodologies, questions, and challenges regarding large-scale fire tests on tunnel lining concrete and the current design guidelines are highlighted. First, this review examines published large-scale testing including unloaded and loaded applications. Secondly, a discussion surrounding the issues faced in testing, including the effects of loading, size reduction, boundary conditions, inclusion of polypyrene fibers and steel reinforcement is presented. Finally, current design guidelines for tunnel fire safety are reviewed and recommendations for future structural fire testing of full-scale tunnel elements was presented.

Exploring the efficacy of natural convection in a cabinet type solar dryer for drying gooseberries: An experimental analysis

A study was conducted to evaluate the efficiency of a cabinet-type solar dryer with naturally convection drying specifically for Indian gooseberries. One notable advantage of utilizing a passive solar dryer is its reliance on natural energy sources, such as solar heat and radiation. By harnessing and utilizing solar energy, the dryer significantly reduces the need for external energy inputs, resulting in lower operational costs and a reduced environmental footprint. This eco-friendly approach contributes to the adoption of sustainable and resource-efficient drying practices. The study involved testing Indian gooseberries in both sliced and unsliced forms within a direct-type passive solar dryer. The aim was to assess their moisture ratio, drying rate, and moisture transport phenomena. Over the drying process, the moisture content of 4.2 kg of Indian gooseberries decreased from an initial moisture content of 78% wet basis (w.b.) to a safe moisture content of 5% w.b. The moisture transport phenomena greatly influenced the shape and size of the drying product, which in turn affected the drying rate. It was observed that sliced gooseberries exhibited a higher effective moisture diffusivity compared to unsliced ones during the drying process. In the solar cabinet dryer, sliced gooseberries dried at a faster rate than unsliced gooseberries. Additionally, the study revealed that the quality of the dried gooseberries produced in the solar dryer surpassed those dried in open sun conditions. In conclusion, passive solar dryer operating at higher temperatures facilitate quicker moisture removal. The findings highlight the potential of utilizing solar dryer for efficient and superior drying of gooseberries, leading to improved product quality.

Monitoring Temperature Profile and Drying Kinetics of Thin-Layer Banana Slices under Controlled Forced Convection Conditions

The drying kinetics of banana slices were examined in a forced convection dryer using an infrared camera to monitor the temperature profile and drying kinetics under control conditions. The air temperature was tested at 40 °C, 50 °C, 60 °C, and 70 °C and the air velocity at 0.2 m/s, 0.5 m/s, and 0.75 m/s, with initial moisture contents of the banana ranging from 76–80% wet basis. The thicknesses of the banana slices being dried were 2, 4, 6, and 8 mm. The optimum drying conditions for the highest drying rate and best color were found to be a temperature of 70 °C, an air velocity of 0.75 m/s, a low relative humidity of 5 to 7%, and banana slices with a thickness of 2 mm. As the air temperature increased, the drying rate and shrinkage also increased. Shrinkage varies concerning moisture loss, and the reduction in radial dimension of banana slices was around 17–23% from the original slice before drying. An empirical mathematical equation was derived by applying the technique of multiple linear regression analysis to the whole dataset of the many experiments of the experimental work. The moisture diffusivity was between 7.88 × 10−10 to 1.04 × 10−10 m2/s, and the average activated energy of the banana was 34.29 kJ/mol. The experimental data were used to fit the drying models. The Midilli model was predicted to produce the closest results to the experimental data.

Moisture-Induced Effects on Lignocellulosic and Humification Fractions in Aerobically Composted Straw and Manure

Humic substances affect compost stability and maturation. However, the intricate structure of lignocellulosic materials hinders the biodegradation of cellulose, hemicellulose, and lignin, often promoting the use of synthetic additives which results in microbial inactivation and death. Therefore, this study examined the effects of optimal moisture levels (MC1 = 45%, MC2 = 55%, and MC3 = 65%) on lignocellulosic and humification fractions in aerobically composted straw and manure. The study showed that 65% moisture content was more efficient in decomposing cellulose, hemicellulose, and lignin, with hemicellulose (115.3% w/w ≈ 47.1%) degrading more than cellulose (76.0% w/w ≈ 39.5%) and lignin (39.9% w/w ≈ 25.9%). However, in compost heaps with 45% moisture, the humic acid concentration increased significantly by 12.4% (3.1% w/w) and 17.3% (4.3% w/w) compared with 55% and 65% moisture, respectively. All moisture levels increased the mineralization of humic substances, but the index measured was highest at 65% MC (23.8% w/w) and lowest at 45% MC (18% w/w). In addition, the humification rate showed the trend: 0.083% w/w > 0.087% w/w > 0.100% w/w for MC1, MC2, and MC3, respectively. Overall, the results indicate that an initial moisture content of 65% is aerobically efficient for the conversion of corn straw and cow manure into stable and mature compost.

Evaluation of the frost resistance of concrete under a sign-alternate temperature load

One of the most important characteristics of building materials is their frost resistance. At the same time, the standard method for determining it, based on fixing the number of cycles of alternate freezing and thawing, does not always meet the requirements for the production of building materials, in particular those for the durability of buildings and structures, and has a number of significant drawbacks. A detailed comparison of the results of laboratory tests of concrete frost resistance and service life in real structures does not allow, in the general case, to establish a direct correspondence between them. In this regard, studies devoted to the development of accelerated methods for determining frost resistance are becoming extremely relevant. New methods should eliminate the main difficulty of this problem, which is the discrepancy between the conditions of laboratory studies and the real conditions in which this material is located in the constructions and buildings in operation. To obtain information about the frost resistance of concrete under real operating conditions, a combined conductometric method for independent measurement of the kinetics of moisture diffusion and ice formation in the process of one-sided freezing of samples is proposed. It is shown that in concrete samples that are subjected to one-sided freezing, that is, they are in conditions as close as possible to the actual operating conditions in building structures, intense mass transfer processes take place. The rates of propagation of the front of ice formation and diffusion of moisture and the corresponding depth of freezing of concrete samples depending on the capillary-porous structure and initial storage conditions are established. In general, the conducted studies made it possible to obtain a more reliable picture of the behaviour of concrete under sign-alternating temperature loads and conditions of different initial moisture content (including in hydraulic structures) than is provided for by the current regulatory documents. The rapidity of measurements makes it possible to use the proposed method for assessing the frost resistance of materials with one-sided freezing under real operating conditions and to effectively control the technology for manufacturing building materials with desired properties.

Tray drying of medical cannabis inflorescences at industrial scale: Kinetics measurement and modeling towards the implementation of statistical process control

The production of medical cannabis in compliance with the guidelines of Good Manufacturing Practice requires a science-based control strategy for the process. In this work, we hypothesized that industrial tray drying process of cannabis inflorescences can be achieved through an accurate selection and fitting of mechanistic models. In total, three industrial runs were measured and modeled from an initial moisture content of 70–72 wt% to a final content of ≤12 wt%. The temperature, relative humidity, and flow rate of convection air were kept constant at 20 °C, 50 %, and 9800 m3h−1. A two-period model based on external resistance and intraparticle diffusion (FUMM+SPPM) was the best to describe the process, with a fitting error of 16.9 %. A control chart was conceived using FUMM+SPPM and a non-linear relation for the standard deviation along time. The suitability of the FUMM+SPPM was demonstrated with a validation run, resulting in a prediction error of 11.5 %; and where the upper and lower control limits of the control chart were respected. A sensitivity analysis showed that the initial moisture uncertainty can offset by 11.6 % the duration of the drying process. A deeper analysis on the fitted intraparticle diffusion coefficients points the migration of water to resemble osmotic movement. Globally, this study validates the adopted pathway to launch and improve a statistical process control for the tray drying of medical cannabis inflorescences.

Soil Moisture Content from Spectral Reflectance Using Visible, Near-Infrared, and Short-Wave Infrared Light

Quantification of soil moisture content is important for understanding physical processes that occur on and within the earth. The methods that are currently used for the determination of soil moisture content are point-based (gravimetry, time-domain reflectometry, neutron scattering, or gamma ray scanning). Remote sensing methods exist but have several disadvantages (poor resolution and dependence on local meteorological conditions). The objective of the study described herein was to determine soil moisture content by means of remote sensing from hyperspectral imagery. Reflectance values obtained from optical remote sensing (wavelengths from 350 nm to 2,500 nm) were acquired from materials with different moisture content levels. Reflectance values, obtained from a spectroradiometer, were obtained for three soils and two commercial sands and then correlated with the initial soil moisture content obtained from gravimetric methods. The correlations were based on the collected reflectance values at prescribed wavelengths and a continuum analysis across all wavelengths. For all investigated materials, the reflectance values decreased with increasing moisture content. The best results were obtained when 1,900 nm was considered (coefficients of determination greater than 0.94, indices of agreement greater than 0.97, coefficients of efficiency greater than 0.41, mean absolute error less than 1.2 percent, and root mean square error less than 1.6 percent). With the continuum analysis, 1,450 nm was the best wavelength. Based on these results, a correlation was observed to exist between soil moisture content and the spectral reflectance values. Using this technique, the determination of soil moisture content can be rapidly obtained (within seconds).

Mechanical characterization of bamboo pole for building engineering: A review

Bamboo is a sustainable and cost-effective alternative to traditional construction materials. Despite the fact that three species are well known for structural applications, namely Dendrocalamus asper, Gigantochloa scortechinii, and Gigantochloa levis, the scientific data for their mechanical characterization is scarcely available and widely dispersed. In addition, a systematic literature review appraising the study advancement of mechanical characterization of bamboo had been unavailable. This paper bridges this gap by conducting a systematic literature review (SLR) of the available literature of mechanical characterization of bamboo pole. A total of 54 relevant articles were retrieved from Scopus and snowballing and then put forward through bibliometric analysis using VOSviewer. The results showed that the distribution of data for physical and mechanical characterization of aforementioned species was scattered due to the different location (origin), age, and initial moisture content recorded during empirical work among the researchers. This review’s importance and distinctiveness lie in its synthesis of the existing literature on bamboo mechanical characterization. The findings provide a point of reference for both academia and industry by bridging the scarcity of current bamboo engineering data and outlining future possibilities for bamboo research in the building and construction domain.

Mass transfer and color change kinetics of infrared drying of rose petals and its impact on physico‐chemical properties

AbstractThe present study investigated the effects of infrared and forced convective air at different infrared power levels (300, 400, and 500 W) and hot air temperatures (50, 57, and 65°C) on thin layer drying of rose petals. Infrared drying requires 50%–52% less time as compared with forced convective drying. The initial and final moisture content of rose petals were 84% (w.b.) and 4.5% (w.b.) respectively. The Midilli–Kucuk model gives a superior fit for both the drying methods followed by Avhad and Marchetti, and the Page model. The zero‐order, followed by the first‐order color kinetics model gives the best fitting for L*, a*, and b* values. Moisture diffusivity was increased by infrared power (1.7308 × 10−8 to 4.1495 × 10−8 m2/s) and hot air temperature (9.3715 × 10−9 to 1.1709 × 10−8 m2/s). The activation energy obtained for rose petals in hot air dryers and infrared dryers was 51.09 kJ/mol and 6.50 kW/kg, respectively. Samples dried at 500 W infrared drying for 18 min demonstrated higher retention of color, ascorbic acid (61.03 ± 2.6 mg/100 g), and anthocyanin content (295.75 ± 65.70 mg/100 g) in the rose petals.Practical ApplicationsSeveral drying techniques are available, though continuous efforts have been made to improve drying methods in terms of energy efficiency and product quality attributes. The present work has been carried out considering the dearth of information on the influence of infrared power/intensity on drying behavior and product quality of rose petals. Mass and color kinetics has been studied for a better understanding of the process along with rehydration, ascorbic acid and anthocyanin content. Our results showed that the infrared drying has significant industrial importance as it provides an efficient way to dry flowers, preserving their quality and extending their shelf life.

Computational modeling of spatial variation in moisture content and temperature distribution in corn at different superheated steam temperatures

The Superheated steam has been shown to be more effective than hot air for drying corn. Modeling studies have been carried out in fluidized bed dryers to determine the moisture and heat transfer characteristics of corn, but there are no modeling studies for a single corn kernel. Knowledge of heat and mass transfer characteristics in a single kernel would produce a better understanding of steam characteristics needed for specific drying rates. The study sought to determine the influence of steam temperature and velocity on the drying rate of a corn kernel. It used computational fluid dynamics (CFD) to model the transfer of heat and moisture between the corn kernel and superheated steam. The simulation used cone geometry to represent the corn kernel. The kernel had characteristic dimensions and 20% initial moisture content. The condition of the steam, which was typical of that found in industry, had temperatures of 120–200°C and velocities of 0.5–1.5 m/s. There was a decrease in the duration of the initial condensation phase as the temperature of superheated steam increased from 120°C to 200°C. The highest steam temperature and velocity resulted in the shortest duration for steam condensation. Contrary to what has been reported, there was no moisture loss from the corn kernel when exposed to superheated steam at 120°C, which may be due to how heat was retained in the drying chamber. Thus, the processes of tapping steam and retaining heat are important elements in the operation of industrial steam driers.

Box-Behnken design optimization of xylanase and cellulase production by Aspergillus fumigatus on Stipa tenacissima biomass

ABSTRACT Optimization of xylanase and cellulase production by a newly isolated Aspergillus fumigatus strain grown on Stipa tenacissima (alfa grass) biomass without pretreatment was carried out using a Box-Behnken design. First, the polysaccharides of dried and ground alfa grass were characterized using chemical methods (strong and diluted acid). The effect of substrate particle size on xylanase and carboxymethylcellulase (CMCase) production by the selected and identified strain was then investigated. Thereafter, experiments were statistically planned with a Box-Behnken design to optimize initial pH, cultivation temperature, moisture content, and incubation period using alfa as sole carbon source. The effect of these parameters on the two enzyme production was evaluated using the response surface method. Analysis of variance was also carried out, and production of the enzymes was expressed using a mathematical equation depending on the influencing factors. The effects of individual, interaction, and square terms on production of both enzymes were represented using the nonlinear regression equations with significant R 2 and P-values. Xylanase and CMCase production levels were enhanced by 25% and 27%, respectively. Thus, this study demonstrated for the first time the potential of alfa as a raw material to produce enzymes without any pretreatment. A set of parameter combinations was found to be effective for the production of xylanase and CMCase by A. fumigatus in an alfa-based solid-state fermentation.

Effects of pre-dynamic loading on hydraulic properties and microstructure of undisturbed loess

The frequent earthquakes in the loess area and the geological disasters induced by them have caused huge threats to the safety and property of the local residents, and most disasters are highly dependent on moisture in the soils. In this study, the effects of pre-dynamic loading on the hydraulic properties of loess are investigated through the variation of soil water characteristic curves, which control the interaction between soil and moisture. The results are analyzed based on the combination of mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) tests, which reveal the influence of pre-dynamic loads on microstructure, for a more comprehensive understanding. It is found that both the initial water content of soil samples and the magnitude of applied pre-dynamic loads have impacts on soil water characteristic curve (SWCC). When initial moisture content is low, the dynamic load causes the loess structure to form a seismic damage zone, resulting in downward movement of SWCC and a reduction in the air entry value. When the moisture content is high, the soil structure gets denser after vibration, leading to reversed influence. For both cases, the effect increases as the PGA amplitude increases. The outcomes of different experiments have achieved good agreement.

Heat and Mass Transfer, Quality, Performance Analysis, and Modeling of Thin Layer Drying Kinetics of Banana Slices

Abstract In this study, experimental works were carried out in three different drying methods named heat exchanger-evacuated tube-assisted drying system (HE-ETADS), greenhouse solar dryer (GHSD), and open sun drying (OSD) to compare thin-layer drying kinetics, concept of mass transfer, and quality assessment of banana slices. Initial moisture content (MC) of banana slices was obtained as 78 ± 2.0% (wb), which decreased to 23.2 ± 2.0% (wb), 25.6 ± 2.0% (wb), and 28.8 ± 2.0% (wb) in all three drying systems, respectively, in 9 h of drying time. Average drying rate was evaluated as 7.89, 7.65, and 7.25 g water/g solid h in HE-ETADS, GHSD, and OSD, respectively. Weibull model (WM) defines thin-layer drying kinetics of banana slices in all three drying processes. Maximum hardness and shrinkage factor of dried banana slices were obtained as 373.6 g and 75%, respectively, in HE-ETADS. Effective moisture diffusivity, activation energy, and mass transfer coefficient were computed as 1.11–2.48 × 10−07 m2 s−1, 30.25 kJ/mole, and 3.21–1.0 × 10−04 m/s, in HE-ETADS. Similarly, in GHSD and OSD, these factors were observed as 1.21–2.34 × 10−07 m2 s−1, 41.25 kJ/mole, 3.15–1.0 × 10−04 m/s and 1.3–2.21 × 10−07 m2 s−1, 56.89 kJ/mole, 3.01–1.0 × 10−04 m/s. Maximum total color changes were noted in OSD. Hence, HE-ETADS can potentially dry high moisture content crops effectively within a minimum drying period.

Assessment of Drying Temperature and Initial Moisture on Beans and Corn Seeds Drying Kinetics and Transport Properties

The purpose of this study is to assess the drying temperature and initial moisture content on beans and corn seeds drying kinetics and transport properties. It was verified that the best empirical lumped models fitting whereas obtained by Approximation of Diffusion and Hii, Law and Cloke models. This was expected because the fitting tends to improve as the model has more parameters. However, despite having only two parameters, the Page model showed good fitting in all conditions analyzed, therefore, this generalized model could predict experimental data with a maximum global deviation of around 10.0 %. The distributed parameter model assessed moisture content distribution inside the grain, which could predict experimental data with an overall deviation of around 10.0 %. Results indicated that both drying temperature and initial moisture have a significant influence on drying rates and mass transfer coefficients and verified that it is not advisable to neglect the influence of the initial moisture content and its distribution along the position inside the material for beans and corn seeds drying studies.

A New Mode of a Natural Convection Solar Greenhouse Dryer for Domestic Usage: Performance Assessment for Grape Drying

It is known that the natural convection (NC) solar drying process is a simple and cheap method for drying foodstuffs, but it is not preferable for common users in the case of drying high-moisture content agro-products due to the slow rate of drying. Meanwhile, the forced convection (FC) drying process is most appropriate for such products, but its economic feasibility may be affected due to high initial and maintenance costs. Therefore, the present study proposed a controlled natural convection (CNC) drying mode using a solar greenhouse dryer (SGD) for drying grapes with two types of cover materials, glass and Plexiglas, through intermittent operation with a PV system to save energy as a simple and inexpensive domestic dryer instead of the common forced convection SGD and the conventional natural convection SGD. The obtained results of the new CNC drying mode using a Plexiglas SGD showed a higher drying rate than the NC drying mode and are close to the FC drying mode using the same cover material. The initial moisture content of the grapes was reduced from 5.91 g water/g dry matter to the final moisture content of 0.15 g water/g dry matter within 12 h and 15 h for the CNC and NC drying modes, respectively, using the Plexiglas SGD. Moreover, the thermal drying efficiency for the two mentioned drying modes was 12.5 and 9.7%, respectively. The Page model was found to be the most appropriate model to predict the kinetics of the SGD in all drying modes, regardless of the cover type. The new CNC drying mode using the Plexiglas SGD achieved the lowest cost per kg of dried grapes (1.26 USD/kg), the highest total saved costs over the lifespan of the dryer (USD 245.46) and the shortest payback period (1.08 years) compared to the other two dryers, NC-SGD and FC-SGD. Generally, the CNC-SGD had good performance over the NC-SGD because it is not affected by the fluctuation in the volume, velocity and direction of the inlet ambient air/wind during drying grapes as a high-moisture content product without external heating sources or complicated parts. Thus, the proposed drying system has the advantage in terms of simplicity, cheapness and saving energy compared to FC-SGD.

Qualitative, energy and economic analysis of forced convective solar drying of tomatoes slices

Solar drying is a thermodynamic method of controlling moisture content that uses a non-depletable free renewable energy source. This work discussed a qualitative and economic analysis of a forced convection drying system for tomato slices in an agricultural greenhouse under Tunisian climatic conditions. Then an exergy and energy balances of the drying system were presented. The tomato’s thin layer was dried in a mixed convection solar drier for 79 h and 127 h in a conventional sun drying process from an initial moisture content of 20.27 to 0.36 kg H2O per kg of dry matter. Energy and exergy analyses of the tomato’s drying process were investigated. It was also discovered that the exergy efficiency of the drying chamber ranged from 16.44 percent to 70.47 percent. The overall efficiency of the greenhouse and the solar air collector were calculated to be 42 percent and 62 percent, respectively. To determine the quality of fresh and dried tomatoes, color analysis was performed. A cost-benefit analysis was performed, and the payback period for the system was estimated to be 1.82 years.

Evaluation of Thin Layer Models for Simulating Drying Kinetics of Black Nightshade Seeds in a Solar-Exhaust Gas Greenhouse Dryer

The current study aimed to use, besides solar, waste heat from exhaust gas of a diesel engine operated for milling of grain, to dry black nightshade seeds. Assessment of thin layer models for simulating drying kinetics of black nightshade seeds was performed in a solar-exhaust gas greenhouse dryer operated on solar; solar-exhaust gas; and exhaust gas modes. In solar mode, seeds took 11 hours to reach a final moisture content of 7.13% (db) from an initial one of 89.34% (db). In solar-exhaust gas mode seeds were dried from an initial moisture content of 92.57% (db) to a final one of 6.07% (db) in 10 hours. In exhaust gas mode it took 14 hours to dry black nightshade seeds from an initial moisture content of 88.84% (db) to a final one of 9.42% (db). Newton, Page, Logarithmic, and Henderson and Pabis thin layer drying models were fitted to experimental data and the best model was selected based on low root mean squared error (RMSE) and interpretation of residual plots. To best explain the prediction of thin layer drying of black nightshade seeds, based on the lowest value of RMSE, Page model was found suitable for solar mode with RMSE of 0.01147206, Logarithmic model was found suitable for both solar-exhaust gas and exhaust gas modes of drying with RMSE of 0.0172098 and 0.02315325 respectively. In conclusion, the thin layer modeling approach can be used to provide design data for a solar-exhaust gas greenhouse dryer.

Effect of pre-germination treatments on seed germination of Passiflora setacea DC (Passifloraceae)


 setacea seeds without aril, were submitted to pre-germination treatments: T1(control); T2 (pre-soaking in Promalin® solution [gibberellin (GA4+7) + N-(phenylmethyl)-1H-purine 6-amine (6-benzyladenine) both at a concentration of 18.8 g.L-1] in bainMarie, 45 °C/20 min.; T3 (osmopriming with KNO3 at a concentration of 2.6g.L-1 H2O, 25 °C/1 day, with aeration); T4 (osmopriming with KNO3 at a concentration of 2.6g.L- 1 H2O, 25 °C/2 days, with aeration); T5 (T3 followed by T2) and T6 (T4 followed by T2). The initial moisture contents, ranging from 6.7% to 8% did not differ from each other (α 0.05). The highest fresh mass increment at 168h and the highest moisture content at the end of the germination test were achieved by T2, 40.9% and 44.3%, respectively. The lowest fresh mass increment at 168h was T1 (13.1%). Osmopriming with KNO3 and aeration contributed to better water absorption in T3 and T4 than in T1, but did not stimulate the germination performance of the seeds. The highest germination percentages and germination speed indexes were obtained from T2 seeds (92% and 8, 4595), T5 (96% and 11.7438) and T6 (94% and 11.6728) as well as the lowest mean germination times T2 (11.73 days), T5 (9.49 days) and T6 (8 .81 days), which did not differ statistically from each other (α 0.05). However, the germination process took less time for T2 seeds, 21 days. The combination of aryl removal and phytohormone solution in a bain-marie at 45 °C/20min. with or without osmopriming with KNO3 stimulated the germination process of P. setacea seeds.

Asystasia intrusa: Cover crop and water balance dynamics in oil palm plantation

Cultivation of A. intrusa as cover crops in oil palm plantation plays a role in reducing water deficit as much as 90% on condition of higher water deficit occurred. The present study aimed to examine the roles of A. intrusa as land cover crop on water balance in oil palm plantation in Bireuen Regency, Aceh Province, Indonesia during the year of 2020. The initial soil moisture content during the experiment were measured at various depths and conducted using a sensor connected to multimeter. The hydrological variables observed were included rainfall, interception of oil palm plants, water interception of A. intrusa, A. intrusa evapotranspiration, initial soil water content, soil water content during the experiment at each predetermined soil depth and percolation. This study showed that with A. intrusa as cover crop, positively affected soil water content especially during dry season and on months when rainfall are moderate. A. intrusa as cover crops in oil palm plantation played an important role in affecting water balance by reducing ground water deficit during dry season or months with lower rainfall.