Evaluation of an automatic drainage recirculation system in rose crop in terms of S, Na+, and Cl-

In the soilless system crop of Colombian floriculture, the carnation cut flower is one of the most representative. The aim of this study was to determine the content of N, P, and K in the substrates based on burned rice husk (BRH) and coconut fiber (CF), in leachates, and in the tissue of the whole carnation plant, with three percentages of recycling. The study was carried out under greenhouse conditions, with standard carnation cv. Delphi planted at a density of 24.3 plants/m2, fertigated through a computerized system and an automatic drainage recycling system. A randomized complete block experimental design in a split-plot with nine treatments and three replications was used. The concentration of nitrate in the leachate was influenced by recycling levels, and that of the ammonium ion by the substrate with the highest BRH content; the percentage of N in the substrate decreased significantly with the increase in the BRH content. Phosphate content in the leachate was significantly higher in the treatment with 100% recycling and with the increase in the percentage of CF in the substrate; in the substrate, the P content also increased as a function of the increase in the percentage of CF. The concentration of the K in the leachate was significantly higher in the treatments without recycling and with a higher percentage of BRH; a significantly higher content of K is highlighted in the substrates with higher CF content.

In recent years, rice husk and coconut fibre started to have substantial commercial value in the industry due to the research being conducted on these agricultural wastes as a new raw material consisting of high fibres and abundant resources. Therefore, this investigation determines the suitability of producing cushion packaging from rice husk and coconut fibre while reducing the amount of pulping material required from virgin wood and the usage of petroleum for making Polystyrene. This study aims to design cushion packaging from rice husk and coconut fibre using the lean concept while studying the compatibility of these cushions as primary packaging. The cushion is designed using AutoCAD software. Three types of cushion packaging models are created using different compositions of rice husk (RH) and coconut fibre (CF): Model 1 (100% RH 0% CF), Model 2 (50% RH 50% CF), and Model 3 (0% RH 100% CF). Each composition is combined with 450g of latex adhesive and 50g of water. The impact performances of cushions from different compositions are conducted using the Drop Tester Model AD-100 Design Series 4410 based on the Standard ASTM D 5276 (Drop Test of Loaded Containers by Free Fall 1998). Model 2 (50% RH 50% CF) gave the best performance in the capability to withstand the impact at a fixed height of 92 cm in the drop test compared to Model 1 (100% RH 0% CF) and Model 3 (0% RH 100% CF). Thus, the composition of rice husk and coconut fibre is the most suitable as packaging cushioning compared to the cushion with a single composition of rice husk or coconut fibre.

This study focuses on the stabilization of soft soil, which has a low bearing capacity and is prone to significant deformations and high moisture content. Soft soil is one type of soil with a poor bearing capacity, and when loaded, it significantly reduces the likelihood of a nonuniform decline. The aim of this study is to determine the physical properties of soft soil and to determine the mechanical properties of soft soil mixture with rice husk and coconut fibre with curing days of 14, and 21 days. The significance of this study lies in its contribution to establish a strong foundation and stabilizing soil, which plays a crucial role in constructing solid and durable structures, ensuring their stability and longevity. By utilizing rice husk and coconut fiber as soil stabilizers, the study also addresses environmental concerns by substituting natural resources with unwanted or discarded materials. Furthermore, this approach offers an economically viable solution for soft soil stabilization. The study involved two types of soil samples. The first type served as a control sample without any rice husk or coconut fiber, while the second type included rice husk and coconut fiber. The second type of sample was further divided into two ratios, with curing durations of 14 days and 21 days. A soil sample was collected from a paddy field in Sg Balang, Muar, Johor. The rice husk was burned at temperatures below 800 °C, resulting in silica-rich ash. The physical and mechanical properties of the soft soil mixture with rice husk and coconut fiber were determined through various tests. The preliminary tests were conducted to assess the physical qualities of the soil, including the Atterberg Limit Method, Compaction Test, and Direct Shear Test. The results showed that the Liquid Limit (LL) was 20.1%, with moisture content ranging from 15.56% to 27.38%. The compaction test indicated that a ratio of 2 with a 21-day curing duration achieved a maximum dry density of 0.56 and an optimum moisture content of 47.8%. The Direct Shear Test demonstrated that a ratio of 1 with a 21-day curing period exhibited the highest shear strength and shear stress at 3.25 kg and 10.45 kPa, respectively. Moreover, the cohesive and friction angle increased with longer curing days, with the mixture of ratio 1 and 21 days showing the highest values at 4.7 kPa and 35.03°, respectively. In summary, the presence of rice hush and coconut fibre significantly improve the soft soil stabilization. The study suggests that further research should explore longer curing periods of 30 days and 60 days to enhance shear strength.

Seedling formation is one of the most important phases for the eggplant crop cycle. One of the decisive factors for obtaining quality seedlings and the consequent increase in productivity is the type of substrate used. The objective of this research was to evaluate the growth of eggplant seedlings grown in alternative substrates with increasing levels of “moinha” (residue from the coffee dry milling process) replacing the commercial substrate. The experiment was carried out in a completely randomized design, with six treatments and ten replicates. The treatments were: T1: commercial substrate (control); T2: 0% moinha (MO) + 40% burnt rice husk (BRH) + 15% coconut fiber (CF) + 5% eggshell (ES) + 40% commercial substrate (CS); T3: 10% MO + 40% BRH + 15% CF + 5% ES + 30% CS; T4: 20% MO + 40% BRH + 15% CF + 5% ES + 20% CS ; T5: 30% MO + 40% BRH + 15% CF + 5% ES + 10% CS; T6: 40% MO + 40% BRH + 15% CF + 5% ES + 0% CS. The electrical conductivity of the substrates and the seedling total dry mass, plant height and stem diameter were evaluated. It is recommended to use the substrate containing 20% MO + 40% BRH + 15% CF + 5% ES + 20% CS.

Soilless culture systems with drainage recycling require continuous monitoring of electrical conductivity (EC) and pH, which are basic indicators of the chemical state of the solution that determine the extent to which recycling of nutrients is possible. These indicators are influenced by the physical, chemical, and microbiological properties of the substrates, as well as evapotranspiration, substrate temperature, and the stage of plant development. A rose crop cv. ‘Charlotte’ was established in three different substrates composed of mixtures of coconut fiber (CF) and burned rice husk (BRH). An automatic drainage recycling system was implemented with three percentages of nutrient recycling (0, 50, and 100%) to record the changes in EC and pH over 8 weeks of cultivation. This bifactorial experiment was carried out under a split-plot design in randomized complete blocks, where the main plot corresponded to the recycling percentage factor and the subplot to the substrate factor. The EC was significantly higher when recycling the nutrient solution in the following substrates: 35% BRH and 65% CF (35BRH) and 65% BRH and 35% CF (65BRH) at 1, 2, and 3 weeks after pruning (WAP). It was also higher for 100% BRH (100BRH) and 65BRH at 7 and 8 WAP. At 6 WAP, recycling at 50% and 100% had a significant effect on the EC values independent of the substrate. This could be caused by the release of ions and higher water retention, typical of CF, and the high adsorption of ions by the BRH. For pH, the trend was acidification, which was significant for the 100BRH treatment without recycling between 0 and 4 WAP. This could be related to changes in the absorption of ions such as NO3- and the activity of nitrifying microorganisms facilitated by the properties of the CF.

Adding natural fibers to concrete is a modern technique in construction industry. The aim of conducting the research is to compare the load carrying capacity of Reinforced Cement Concrete (RCC) columns by adding natural fibers in it. Total 30 columns were casted for observing the compressive strength of the column. Natural fibers like Rice husk, wheat husk, coconut fiber and wood fiber were added in 1 % and 3 % by weight of cement. On varying the percentage of replacement from 1% to 3%, rice husk was having the most positive impact on loading capacity as its load carrying capacity raises 1.67 times of normal column. On considering the all tests performed, rice husk fiber was found to be the best in replacement in concrete. The strength of the Fiber Reinforced columns (FRC) varies from 0.76 to 1.67 times in comparison to plain column. Adding fibers to the concrete raised the strength of column in the range of 1.5 to 3 times of design load. Coconut fiber columns showed poor ductility as compared to the other natural fibers i.e. wheat husk, rice husk and wood fiber. The coconut fiber column showed debonding between fibers and concrete at the time of ultimate loading. Failure of FRC column was nearly same as plain column. Hence natural fiber concrete is one of the environment friendly and economic option, which is used to construct low rise building

Scientific investigations on the non-chemical modification of lignocellulosic fibers are important for engineers when they design green wood-plastic composites. Two types of lignocellulosic fibers, namely rice husk and rice straw fibers, were studied. The physicochemical and thermal properties of the fibers with and without seawater modification were compared. The results suggested that seawater modification improved the physicochemical and thermal properties of the fibers, and that it specifically increased the surface roughness, crystallinity, and pyrolysis temperature at 5% weight loss, and decreased the silicon, hemicellulose, and lignin content of the fibers. Compared with rice husk fibers, rice straw fibers exhibited a high growth ratio of crystallinity and pyrolysis temperature at 5% weight loss, and a high loss ratio of silicon. Seawater modification of rice husk and rice straw fibers could improve fiber–polymer compatibility.

Particle boards are one of the primary products used in buildings and furniture sectors. These materials are manufactured under pressure, by combining wood particles and other lignocellulosic fibrous materials by using an adhesive. The extensive use of particle boards can add to the economic advantage of low-cost wood raw material, inexpensive agents and, simple processing. For the manufacturing of particle boards based on renewable resources, the search for lignocellulosic substitutes for wood is one of the biggest challenges that the wood industry is facing. In this project, particle boards were made using rice husk and coconut fibre, as a substitute for wood. Rice husk is the hard-protective shell of grains, obtained from rice mill. Coconut fibre is the natural fibre extracted from the coconut husk. Three boards of different coconut fibre content (15%,20%, and 25%) were casted. The coconut fibre and rice huskwere exposed to Alkali Treatment to make the fibre free from hydrophobic substances. They were then processed into particle board using poly-ester resin as binder. The effect of fibre content on Density, Water Absorption (WA), Thickness Swelling (TS), Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) were analyzed. This investigation appears as a better solution for environmental problems associated with wastes and it is economical to use for the manufacturing of composite fibre boards.

13 - The use of rice straw and husk fibers as reinforcements in composites

This study focuses on surface modification of local made fibres for use as reinforcement in the area of polymer matrix composite. Modified oil palm and Rice husk fibres were prepared by using alkaline treatment and the samples were investigated by using Helium pycnometry, Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray fluorescence (ED-XRF) and Field emission scanning electron microscope (FESEM). The oil palm fruit bunch and rice husk fibres were treated with 6.0 w.t % Sodium Hydroxide (NaOH). In order for the treated fibre to be compared, fibres without alkaline treatment were prepared. All the prepared samples were crushed and a sieving machine was used to prepare 100μm particles sizes. The changes in composition of the both fibres due to leakage of original elements as well as the changes in density have been successfully determined by these techniques. Density for both oil palm (OP) and rice husk (RH) fibres decreased after treated. A series of FT-IR spectra confirmed the reduction of the Hemicelluloses and Lignin content after the treatment. The significant changes between untreated and treated fibres were also discussed, whereby the rough surface of fibres becomes smooth due to elimination of impurities. ED-XRF analysis confirmed the percentage of Silica (Si) content for both fibres and proved the reduction of elements present in the composition.

Burned rice husk is produced from the rice husk which is processed using a certain method to produce burned rice husk. The process of changing the rice husk into burned rice husk is aimed to increase the carbon content. With the increase in carbon content, the ability to absorb the micro wave increases. We choose the rice husk material because Indonesia produces 15 tons of rice husks for every rice harvest annually. Therefore, it is possible to explore the potential of rice husk and/or burned rice husk into a microwave absorber material. The material containing carbon is chosen because carbon can cause the material to become a good conductor, with low density, and low elasticity. This characteristic causes the rice husk to influence the reflection and absorption of waves. In addition, carbon also functions as a resistive material that converts the current into heat and evenly spreads around it. The assessment of rice husk as an absorber has been conducted and resulted in a conclusion that the rice husk serves as a good absorber of micro wave. With higher carbon content, it enables the burned rice husks to have much better absorber ability than the rice husk. This paper presents the measurement and simulation of burned rice husk material as microwave absorber. By comparing the ability of rice husk and burned rice husks, it is concluded that burned rice husk has better ability to absorb.

The acreage of cut flowers grown on soilless substrates in Colombia has increased substantially over recent years. However, the know-how regarding substrate properties is too empirical, and few studies have been carried out on their physical characteristics. The present paper studies the hydro-physical characteristics of burnt rice husks, coconut fiber and mixtures of both, in proportions of 35:65 and 65:35. Particle size distribution, solid and bulk density, total porosity, air and water distribution (easily, heavily, and reserve water, and saturated hydraulic conductivity) were analyzed for each substrate at several phenological stages of rose crops. The results showed values for solid density similar to those previously reported, ranging between 0.77 g·cm -3 for burnt rice husks and 0.81 g·cm -3 for the 65:35 mixture. Bulk density is highest on burnt rice husks (0.26 g·cm -3 ) and lowest on coconut fiber (0.13 g·cm -3 ), mixtures show proportional intermediate values. Coconut fiber displayed bigger particle size (from >2.5 to 0.63 mm), whereas burnt rice husk has higher values of fine particle size (0.63 to <0.08 mm), and that fraction will increase with the crop's age. These differences in particle size affect the water retention curve and the water types for each substrate type. Air content and easily available water might help us to define adequate water management and efficiency on different substrates, and will be predicted by single linear regression of the mixtures. Production and quality of rose stems were affected by the substrate type.

In the hydroponic growing systems of the Bogota plateau, excess amounts of ions have been found in the leachate. The aim of the study was to determine the Ca, Mg and S contents in the substrate, leachate and tissue of the entire plant of the standard carnation cv. Delphi, with three leachate recirculation percentages and in different phenological development stages. A randomized complete block experimental design in split plots with nine treatments and three replications was used. The calcium concentration in the leachate on the basis of recirculation was significantly higher without recirculating the leachate, whereas, on the basis of the substrates, it tended to be higher in the substrate with a lower percentage of burned rice husk (BRH). For magnesium, the concentration in the leachate increased with crop development, regardless of the factors, and was significantly greater as the recirculation percentage increased. The calcium and magnesium contents were significantly lower in the substrate with higher BRH content. The sulfate concentration in the leachate increased as the recirculation percentage increased, and the highest concentrations occurred under the influence of the substrate with higher coconut fiber (CF) content. In closed systems the magnesium and sulfur concentrations in the fertigation formulas must be adjusted. Furthermore, when CF percentages are maintained in the substrate, it is necessary to consider the retention of the calcium and magnesium ions.

Improper disposal of agricultural waste is causing problems in the world today. Since it was seen that using rice husk and coconut fiber can help humans and their environment, this study investigated if coconut fiber and risk husks are potential alternative ingredients in making cement boards. With this, a quantitative experimental design was used to answer the questions this study sought. After the experiment, it was found that rice husk-coconut fiber is not feasible enough in terms of its flexural strength; however, using the rice husk-coconut fiber cement board for interior purposes is recommended. With the limitations of the study, it is also recommended for future researchers to survey rice husk-coconut fiber cement board to use variations with higher water, rice husk, coconut fiber, and cement ratio that can improve the strength and durability of the rice husk-coconut fiber cement board.

A greenhouse experiment was conducted for 130 days to assess the effect of application of uncoated urea (UA) and 3,4-dimethylpyrazole phosphate–coated urea (UDMPP) on mineral nitrogen (N) content [ammonium (NH4 +)-N and nitrate (NO3 −)-N] in leachates and growing media. Charlotte rose plants grafted on Natal Briar were cultivated in four different media [soil, 100% burnt rice husks (100BRH), a mixture of 65% burnt rice husks and 35% coconut fiber (65BRH), and 100% coconut fiber (100CF)] and fertigated with UA or UDMPP at rate of 170 mg N·L−1. Results showed that fertilizer induced slight acidity in the leachate collected in all growing media. The use of DMPP diminished cumulative nitrate losses by ˜65 and ˜60%, in soil and coconut fiber leachates, respectively, as compared to the plots with UA. The UDMPP did not have any effect on nitrate losses in BRH media.