Carbonized Rice Hull Research Articles

Efficacy of Vermicast from Local Earthworms as Growing Media of Eggplant (Solanum melongena L.)

The study aimed to determine the effectiveness of vermicast from local earthworms as a growing medium for eggplant, with the goal of exploring the potential of organic fertilizers in boosting vegetable yields and promoting sustainable agriculture practices. It investigated the efficacy of vermicast derived from local earthworms in enhancing seed germination and seedling growth of eggplant using a randomized complete block design with four treatments and three replications. The experiment compared garden soil, vermicast, carbonized rice hull, and combinations of these growing media, evaluating germination percentage, seedling height, number of leaves, and leaf area. Results showed significant differences among treatments, with vermicast and carbonized rice hull exhibiting superior performance compared with garden soil. Carbonized rice hull showed the highest germination percentage in the second and third weeks, while vermicast from local earthworms led to the tallest seedlings and highest leaf area in subsequent weeks, suggesting its preference for cultivating eggplant seedlings. The study highlights the potential of vermicast from local earthworms as a sustainable and effective organic soil amendment for enhancing eggplant growth.

Botanical Leaf Extracts and Mulching Materials in Organic Eggplant (Solanum Melongena L.) Off Season Production

The extensive use of pesticides and the risk they pose to human and the environment requires safe alternatives in crop production hence the study on the efficacy of botanical leaf extracts and mulching materials in organic eggplant production. This study determined the best level combination of botanical leaf extracts that has repellent and knockdown effects on major eggplant insect pest, best level combination of botanical leaf extracts that produces the highest marketable yield; best mulching materials; best level combination of botanical leaf extracts and mulching; correlation of infestation to yield; profitability of eggplant production using botanical leaf extracts and mulching materials combined; and evaluate the effects of botanical leaf extracts and mulching materials on soil chemical properties. A Bioassay test on the botanical leaf extracts was conducted prior to field experiment. Mass rearing the test insects was done to ensure uniform number of insect in eggplant per treatment. A Split- plot in Factorial Design was used in the study with three blocks. The main plot were the leaf extracts of Neem, Madre de Cacao+ Guava at 1:1:1 ratio were: P0 – No Application, P1 –250 ml leaf extract/16 li water, P2 –500 ml leaf extract /16 li water, P3 –750 ml leaf extract /16 li water, P4 – 40 ml Commercial insecticide/16 li water. The sub-plot was: M1 – Black Plastic mulch, M2 – Carbonize Rice Hulls, and M3 – Saw Dust. Results of the bioassay showed highly significant knockdown effect in the application of 500-750ml leaf extract/16 li water on fruit and shoot borer, lady spotted beetle and white flies comparable to application of commercial insecticide/16 li water. Significant repellent effects on Fruit Shoot Borer and Lady spotted beetles but no repellent effects on white flies for an application of 250ml botanical leaf extracts/16li water. Results under field condition showed that plants applied with 750ml botanical leaf extracts/16 li water is more effective than commercial insecticide/16 li water in reducing damaged leaves during the early vegetative stage of development (2nd WAT) and at reproductive stage of development (10th WAT). Highly significant difference was obtained in terms in weight of non-marketable fruit. No significant interaction was registered between botanical leaf extracts and mulching materials. Regression correlation analysis revealed that there was a direct correlation between the numbers of damaged leaves to yield. Combined application of botanical leaf extracts at 750ml/16 li water + carbonized rice hulls obtained Php 797,635.15 net for organic off-season eggplant production. Soil pH, OM, P, and K were increased with application of sawdust, carbonized rice hulls and plastic mulch.

Actinomycete inoculant improves the growth and yield of rainfed lowland and upland rice under field conditions

This study aimed to assess the effectiveness of actinomycete inoculant in enhancing the growth and yield of rainfed lowland and upland rice across wet and dry seasons in real field conditions. This field assessment took place at four sites, comprising two rainfed lowland and two rainfed upland ecosystems, over two cropping seasons (dry and wet seasons). The experiments involved testing both soil-based and carbonized rice hull (CRH) inoculants. Actinomycetes were found to be effectively carried by CRH and soil, and evidence from field studies in rainfed lowland and upland conditions showed that the actinomycete inoculant significantly improved rice production even under stressful environmental conditions. Regarding plant height, root depth, and tiller number, the inoculated treatments outperformed both the control and the full fertilization rates. Rice yield significantly increased with the application of actinomycete inoculum in both lowland and upland experiments. Inoculation alone led to substantial improvements, with yield increases of up to 48% in Lowland Site 1, 50% in Lowland Site 2, 78% in Upland Site 1, and 43% in Upland Site 2. Similarly, growth was enhanced by inoculation alone, reaching up to 50% in Lowland Site 1, 75% in Lowland Site 2, 24% in Upland Site 1, and 26% in Upland Site 2. When added to the full rate of fertilization, the inoculant significantly boosted yield by up to 16% in Lowland Site 1, 82% in Upland Site 1, and 40% in Upland Site 2. Additionally, growth substantially improved with inoculation in conjunction with the full rate of fertilization, reaching as much as 50% in lowland site 1, and 24% in upland site 1. Actinomycete inoculant proves to be a valuable alternative and addition to agricultural fertilizer management, as it was found to significantly increase growth and yield even in adverse weather conditions.

Sustainable Water Management: Developing a Hydroponic-Watering System to Support Epiphytic Plant Growth

This study introduces an innovative hydroponic–epiphytic water system designed to address water conservation challenges in urban agriculture. The system involves repurposing water from a hydroponic setup to irrigate epiphytic plants, promoting sustainability and efficient water management. Expert opinions on the system's development and innovations were gathered using a structured evaluation based on key indicators. Notably, the mean scores were analyzed using an Inter-rater reliability assessment in order to determine the expert's opinion on the development and innovations of the hydroponic-epiphytic water system, and indicate strong acceptance in various aspects, including economic profitability, low initial cost, and compatibility with social values. However, identified areas for modification, such as time and effort savings and immediate benefits, offer valuable insights for refinement. The hydroponic–epiphytic system's components, meticulously detailed in the study, contribute to its structural integrity and water circulation efficiency. The chemical composition of the hydroponic solution, emphasizing nitrogen-rich urea, ensures precise nutrient delivery. The hydroponic growing medium, a blend of carbonized rice hull and coconut coir, provides an optimal environment for plant growth. The closed-loop water flow system minimizes wastage by recycling hydroponic water for epiphytic plants, aligning with sustainable gardening practices. In conclusion, the hydroponic–epiphytic water system proves effective in meeting its objectives of innovation and water conservation. Expert evaluations enhance its credibility, and the identified areas for improvement offer a roadmap for optimization. Recommendations include exploring alternative energy sources, conducting extended studies for long-term observations, and a more comprehensive expert opinion study. This study contributes to the advancement of urban-friendly, sustainable water management practices in agriculture.

Ensuring household food security through enhanced production of pechay (Brassica rapa L.) as influenced by different levels of carbonized rice hull integration

Household gardens have been a staple of many rural areas in the region. However, due to limited space, a need to intensify productivity while maintaining our natural resources has risen to the forefront of research innovativeness. The productivity and economic efficiency of pechay applied with varying rates of carbonized rice hull (CRH) were evaluated from February 2021 to April 2021. The study was laid out in Randomized Complete Block Design with five (5) growing media as treatments (T1 - garden soil with the recommended rate of NPK; T2 - growing media (GM) consisting of mixtures of garden soil, chicken dung, and coco peat; T3 - GM + 5% CRH; T4 - GM + 10% CRH; and T5 - GM + 15% CRH) with three (3) replications. Results revealed that the integration of 5% CRH with specialized mixed growing media (T3) significantly increased yield attaining 102.13 kg per 100 m2. Utilization of specialized growing media (T2, T3, T4, and T5) either with or without integration of CRH has higher dry matter yield which was significantly higher than plants harvested from plots grown with purely garden soil. Cost and return analysis revealed that pechay production utilizing the specialized growing media with the integration of 10% CRH obtained the highest return of expenses of Php 2.57 which was significantly higher than the rest of the treatments. The study concludes that the addition of 10% CRH to specialized mixed media is promising based on its yield performance and return on cost invested, thus, it is highly recommended.

Design and Development of a Biochar Pelletizer

Biochar’s potential value as a soil amendment is in continuous demand. However, as-produced biochar comes in different forms and sizes making its application and distribution challenging. Because there is a limited commercialized biochar pelletizer machine in the Philippines, a biochar pelletizer was developed to meet the requirements of the end-user and to produce a relatively efficient and comparatively inexpensive machine. The developed pelletizer was fabricated in local shops. The pelleting mechanism was composed of a horizontal die and two rollers. Pellet rollers were designed to press the biochar against the die. As the mixture passed the holes, pellets were formed and then fell to the catchment. The developed pelletizer was tested using three (3) different feedstocks, namely: carbonized rice hull (CRH), carbonized coconut shell (CCS), and carbonized wood chips (CWC). Cassava paste was utilized as the binder in levels of 10%, 15%, and 20%, respectively. The pellets produced in the study were 13 mm long with a range of 6.60 to 7.79% moisture content. Particle and bulk densities were highest with CRH at 764.22 and 343.67 kg-m3, respectively. The hardness and durability were highest with CWC with 1272.75 Pa and 87.48%, respectively. The highest actual capacity was observed with the CRH at 678.22 kg/day. An analysis of variance showed that the mean machine efficiency ranged from 67.86% to 71.02%, irrespective of the binder level. On the other hand, the binder level had a significant effect on the pelleting recovery with the highest recovery of 98.50%was achieved with a binder level of 20%. CCS and CWC could hold water up to 101 to 104% of their weight and could resist up to 806.66 to 1559.6 Pa of pressure. The study recommends the testing of pellets with other feedstock materials and other binder types and formulations.

Performance of Edible Mushroom Varieties Under Different Agricultural Substrates

The study was conducted at Dr. Emilio B. Espinosa, Sr. Memorial State College of Agriculture and Technology (DEBESMSCAT) Cabitan, Mandaon, Masbate. The experimental design used was 3 x 7 CRD factorial with three varieties of mushrooms (Pink Oyster, White Abalone, and Milky Mushroom), seven agricultural substrates as treatments, Treatment A (70% rice straw and 30% sawdust), Treatment B (70% rice straw and 30% corn cob), Treatment C (70% rice straw and 30% Carbonized Rice Hull), Treatment D (100% rice straw), Treatment E (100% sawdust), Treatment F (100% corn cob) and Treatment G (100% Carbonized Rice Hull). The experiment was replicated three times with a total of 945 fruiting bags. Height, fresh weight, and the number of fruiting bodies are the data that was observed in the study. The result showed that in terms of growth performance, a nonsignificant result was observed in the height performance of the mushroom varieties inoculated in substrates with 70% rice straw, 30% corn cob, and 100% carbonized rice hull. Similarly, the number of mushroom fruiting bodies produced differed among mushroom varieties inoculated. Mushrooms inoculated in 100% carbonized rice hull attained more fruiting bodies than other tested varieties. Mushrooms inoculated in 100% corn cob produced a significantly higher number of mushroom fruiting bodies than other treatments. Finally, the weight of mushroom fruiting bodies produced in 70% rice straw and 30% carbonized rice hull applications was statistically significant for all agricultural substrates inoculated. The researcher concluded that using agricultural substrates other than carbonized rice is effective in mushroom production.

DIFFERENT SUBSTRATES AND IRRIGATION DEPTHS ON PRODUCTION COMPONENTS OF THE ‘BIQUINHO’ PEPPER*

The present work had the primary objective of evaluating the production response and water use efficiency of the Biquinho pepper for different irrigation depths and substrates. The experiment was conducted in a greenhouse located at the Alegrete campus of the Federal University of Pampa. We performed an entirely randomized 2 x 5 two-factor experimental design (two substrate compositions and five irrigation depths). The substrate composition treatments used were a commercial substrate and the mixture of commercial substrate + carbonized rice hull. The treatments for the water replacement depths were 25, 50, 75, 100, and 125% of the water holding capacity for each substrate. At the end of the cycle, we assessed the following components: crop yield, production, water use efficiency, and fruit diameter, length, average weight, and number. The yield and water use efficiency components were more significant when using the commercial substrate + carbonized rice hull composition. The maximum technical production efficiency was obtained for an irrigation depth of 101.7% of the water holding capacity. On the other hand, the water use efficiency was higher when using a depth of 69.17%.

Inoculum source of Phytophthora palmivora jackfruit seedlings health in response to potting media porosity, sanitation, inoculation, and phosphonate application

Seedling dieback caused by <i>Phytophthora palmivora</i> (Butler) is a significant problem in jackfruit <i>(Artocarpus heterophyllus</i> Lam.) nurseries in Eastern Visayas, Philippines. It has been linked to insufficient knowledge of inoculum sources and possible factors contributing to seedlings’ health. This study was conducted to identify potential sources of <i>Phytophthora</i> inoculum in representative nurseries in Eastern Visayas and evaluate the effect of possible factors that contribute to seedling health. <i>Phytophthora</i> detection was conducted from random samples of potting media, irrigation water, germination beds, and roots of seedlings from representative nurseries supplying seedlings in the region. Detection was done through tissue baiting and the use of a <i>Phytophthora-</i>specific diagnostic kit. The effect of the air-filled porosity (AFP) of potting media, sanitation, pathogen inoculation, and phosphonate on plant growth and seedlings’ health was evaluated. <i>Phytophthora</i> propagules were positively detected in most samples, suggesting that seedlings most likely already harbor the pathogen when distributed to farms in the region. Among the factors, AFP of the potting medium had the most profound effect on seedlings’ growth and health. The tallest plants with the largest stem diameter, highest dry weight biomass, and least disease rating were grown in the most porous medium (21 <i>%</i> AFP) consisting of 20 <i>%</i> garden soil, 20 % carbonized rice hull, 20 % rice hull, 20 % coco coir dust, 10 % sand, and 10 <i>%</i> chicken dung. The benefit of a highly porous medium was, however, seen only when external fertilization was undertaken. Unsterilized media resulted in healthier seedlings compared to sterilized media. Sterilized potting media that were inoculated with the pathogen after sterilization resulted in more severe disease. Sterilized potting media was beneficial for jackfruit seedlings when supplied with adequate nutrients and as long as contamination with the pathogen does not occur. Sterile media, therefore, should be kept away from recontamination with the pathogen otherwise more severe disease may occur. The addition of the plant defense regulator phosphonate showed no effect on the growth and health of seedlings under the trial’s conditions.

Effect of Soil Organic Ameliorants with Carbonized Rice Hull on the Growth and Yield of Shallot Onion (Allium ascalonicum L) on Salt Affected Soil

A pot experiment was conducted to test the potential of different soil organic ameliorants in salt affected soils reclamation; to test the effect of soil organic ameliorants on the growth and yield of shallot onion (Allium ascalonicum L.) planted in salt affected soil; determine the most effective soil organic ameliorants on salt affected soil Treatments prepared were; T1- Control Salt affected soil (1.57 kg/pot-1), T2- Vermi-cast (197.40 g/pot-1) with CRH (30 grams/pot-1),T3- Guano dung (39.40 g pot-1 with CRH (30 grams/pot-1), T4- Dried Goat Manure (115.40 g/pot-1) with CRH (30 grams/pot-1), T5- Dried Chicken Dung (94.94 g pot-1) with CRH (30 grams/pot-1), T6- Dried Cattle Manure (214.30 g/pot-1) with CRH (30 grams/pot-1). The study was laid out using Randomized complete block design with treatments and three replications. All organic ameliorants applied to the salt affected soil significantly improved on average bulb diameter, average height, average number of leaves, average bulb fresh weight, average number of tillers and average yield per hectare. It can be concluded that application of organic ameliorants is effective means to address the problem in saline affected soils.

Inoculum source of Phytophthora palmivora jackfruit seedlings health in response to potting media porosity, sanitation, inoculation, and phosphonate application

Seedling dieback caused by <i>Phytophthora palmivora</i> (Butler) is a significant problem in jackfruit <i>(Artocarpus heterophyllus</i> Lam.) nurseries in Eastern Visayas, Philippines. It has been linked to insufficient knowledge of inoculum sources and possible factors contributing to seedlings’ health. This study was conducted to identify potential sources of <i>Phytophthora</i> inoculum in representative nurseries in Eastern Visayas and evaluate the effect of possible factors that contribute to seedling health. <i>Phytophthora</i> detection was conducted from random samples of potting media, irrigation water, germination beds, and roots of seedlings from representative nurseries supplying seedlings in the region. Detection was done through tissue baiting and the use of a <i>Phytophthora-</i>specific diagnostic kit. The effect of the air-filled porosity (AFP) of potting media, sanitation, pathogen inoculation, and phosphonate on plant growth and seedlings’ health was evaluated. <i>Phytophthora</i> propagules were positively detected in most samples, suggesting that seedlings most likely already harbor the pathogen when distributed to farms in the region. Among the factors, AFP of the potting medium had the most profound effect on seedlings’ growth and health. The tallest plants with the largest stem diameter, highest dry weight biomass, and least disease rating were grown in the most porous medium (21 <i>%</i> AFP) consisting of 20 <i>%</i> garden soil, 20 % carbonized rice hull, 20 % rice hull, 20 % coco coir dust, 10 % sand, and 10 <i>%</i> chicken dung. The benefit of a highly porous medium was, however, seen only when external fertilization was undertaken. Unsterilized media resulted in healthier seedlings compared to sterilized media. Sterilized potting media that were inoculated with the pathogen after sterilization resulted in more severe disease. Sterilized potting media was beneficial for jackfruit seedlings when supplied with adequate nutrients and as long as contamination with the pathogen does not occur. Sterile media, therefore, should be kept away from recontamination with the pathogen otherwise more severe disease may occur. The addition of the plant defense regulator phosphonate showed no effect on the growth and health of seedlings under the trial’s conditions.

Effects of Seed Storage Duration and Matriconditioning Materials on Germination and Seedling Characteristics of Maize

Matriconditioning treatments have been reported to improve seed and seedling qualities of many crops after certain storage periods. The research was conducted to evaluate different matriconditioning substances on seedlings characteristics of seeds that previously stored in different periods. The research was carried out from October 2015 to April 2016 at the Indonesian Cereal Research Institute (ICERI). The experiment was arranged in factorial completely randomized design to facilitate the combination of two factors. The first factor was seed storage period, i.e. 4, 36 and 72 months, while the second factor dealt with matriconditioning subtances, i.e without matriconditioning, sawdust, carbonized rice hull and rice straw. The results showed that matriconditioning treatments improved seed and seedling qualities of the maize seeds derived from different storage periods. Shorter seed storage period produced seedlings with higher percentage of germination, germination rate, seedling dry weight, shoots and roots lenghts and lower EC. Among the tested matriconditioning substances, carbonized rice hull provided more suitable condition to improve seedling qualities in any seed storage period than saw dust and rice straw.

How do clonal plantlets of mate respond to different substrate compositions and shading levels?

Mate (Ilex paraguariensis A. St.-Hil) is an arboreal species of great economic and socio-environmental importance in South American countries. This specie presents several difficulties during seminal propagation, and studies related to plantlet production by vegetative propagation are fundamental for obtaining homogenous mate plantations with high leaf productivity. Therefore, the present study aimed to evaluate the effects of substrate and shading levels on the morphophysiological quality of mate plantlets produced by mini-cuttings. Rooted mini-cuttings of four mate clones were cultivated on commercial substrate, subsurface soil and vermiculite (2:1:1 v/v/v), commercial substrate and subsurface soil (2:1 v/v) or subsurface soil, cattle manure and carbonized rice hulls (2:1:1 v/v/v). After 120 days, the plantlets were randomly distributed on benches to evaluate the effects of 50 and 80% shading screens. Regardless of the clone, the commercial substrate and subsurface soil composition allowed plantlet production with satisfactory development of both aerial part and root system at 120 days of cultivation. Clone 06SM17 produced plantlets with high averages of stem diameter, shoot height, number of leaves, total length, surface area, total volume of roots, and number of root tips. Both shade levels resulted in similar stem diameters, shoot heights, numbers of leaves, and a, b, and total chlorophyll indices. Clonal mate plantlets with satisfactory morphophysiological quality are produced in commercial substrate and subsurface soil (2:1 v/v) under 50 and 80% shading.

STUDY ON THE REMOVAL OF AMMONIA IN WASTEWATER USING ADSORBENT PREPARED FROM RICE HULL WITH MAGNESIUM OXIDE MODIFICATION

This study is aimed to evaluate the ability of magnesium oxide-coated carbonized rice hull (MCRH) material for ammonium removal in synthetic and real domestic wastewater. The MCRH material was prepared using waste rice hull from a household rice-processing factory and magnesium chloride salt via a simple mixing and annealing method. The material was then characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effects of magnesium chloride modification and environmental condition such as initial ammonium concentration (20 – 100 mg/L), amount of adsorbent (0.8 –2.0 g/L), and adsorption time (0 –32 h) on the ammonium removal efficiency and adsorption capacity were investigated. Adsorption kinetic and isotherms were also studied for MCRH material. Results showed that magnesium oxide was successfully coated on carbonized rice hull with Mg/C molar ratio of 0.22. Ammonium adsorption isotherm fitted well to Langmuir model with maximum adsorption capacity of 65.36 mg/g. The adsorption was physical process and adsorption kinetic was best described by intra-particle diffusion model with the correlation coefficients ranged from 0.942 – 0.979. Ammonium removal feasibility of MCRH was proved through the treatment of real domestic wastewater containing 80.7±1.6 mg/L initial ammonia concentration with removal efficiency reached 86.8% and the effluent concentration met the allowable value (10 mg/L) as given by QCVN 14 : 2008/BTNMT (column B) - National technical regulation on domestic wastewater. Hence MCRH is potential as a cheap and abundant material in Vietnam and the material after adsorption accumulated ammonium would be the source of fertilizer for soil quality improvement.

ROOTING OF Ficus enormis MINI-CUTTINGS WITH DIFFERENT LENGTHS

Ficus enormis is a native species with great ecological potential, especially for ecosystems restoration. The present study aimed to evaluate the rooting, root and vegetative vigor of Ficus enormis mini-cuttings and to determine its best length for the formation of seedlings. Mini-cuttings were collected from clonal mini-garden, prepared with 2 ± 0.2 cm, 4 ± 0.2 cm, 6 ± 0.2 cm, 8 ± 0.2 cm and 10 ± 0.2 cm of length and diameter of 0.5 ± 0.2 cm. The planting was carried out in plastic boxes filled with commercial substrate based on carbonized rice hulls and coconut fiber, conditioned in a greenhouse. After 45 days, were avaluated the rooting percentage, original leaf maintenance, mini-cuttings with roots and callus percentage, length of the three largest roots/mini-cutting, shoot emission percentage, number of root/mini-cutting and mortality percentage. The results showed that the mini-cuting length did not influenced the rooting percentage, callus and root formation, and root length mean. However, shoot emission, number of root and mortality were influenced by the mini-cutting length.

Silicon Added to Common Bean Seeds: Physiologic and Sanitary Effects

The objective of this study was to evaluate the effect of the of common bean seeds coating with different doses of Si, supplied by the carbonized rice hulls, in its physic, physiologic and sanitary attributes, as well determine the amount of this element absorbed in plants. The experiment was conducted in Laboratory of Seed Analysis belonging to the Universidade Federal de Pelotas-Brazil, during the crop season 2014/2015. For this, common bean seeds of cultivar BRS Expedito were treated at doses of 0, 45, 90, 135 and 180 grams of Si 100 kg-1 of seeds, using a completely randomized experimental design with four replicates The use of different doses of carbonized rice hulls in the seed coat does not alter the physical quality and does not negatively affect the physiological quality of the seeds. Crescent doses of carbonized rice hulls up to 101 g of Si 100 kg-1 of seeds increase the seedlings vigor evaluated by the total dry mass and length of shoot at 21 days after seeding, as well as the Si amount in roots. The root dry mass at 21 days after seeding presents growth reduction with the increase of doses until 104 g of Si 100 kg-1 of seeds, although, without compromising the shoot development and the element accumulation. The different Si doses supplied by the carbonized rice hulls do not control pathogens associated to seeds.

The properties of rice hull in soilless agriculture technique and the effect of plant development parameters in lettuce (Lactuca sativa var. crispa) cultivation

The properties of media used in soilless agriculture technique in plant production affect plant development directly. Media have different properties in order to provide support for the plant in the root part, and also are influential on root development, as well as its water and nutrients intake. Peat, coco-peat and perlite media are the most commonly used materials in the world. However, the high cost of peat aggregate and the limited peat reserve led to the need for seeking alternative media. Rice hull, which will be one of these alternative media, is a material that comes off during rice processing and poses an environmental problem in the form of waste management. Nowadays, minimizing the rice hull waste management problem on the environmental level gains even more importance especially in sustainable agricultural system. Therefore, the evaluation of rice hull, which is considered a renewable source of energy, in the soilless agriculture system has gained great importance. This material can be used not only without being processed but also in ground and carbonized forms. Available studies on the potential of using rice hull as an aggregate are not adequate. In this study, in addition to using peat, coco-peat and perlite media which are commonly used in soilless agriculture, we used fresh, ground and carbonized rice hull in lettuce cultivation. Bulk density (g cm(‑3)), aeration capacity (%), easily available water (%), water buffering capacity (%), porosity (%), moisture (%), organic matter (%), pH and electrical conductivity values were determined in six different media. In addition to this, by cultivating lettuce in soilless mediums, some vegetal data were also collected. Our results showed that rice hull waste can be used as an aggregate. Therefore further studies are needed to overcome the deficiencies on this subject.

Substrates on the cuttings rooting of black pepper genotypes

The soil in the production of clonal seedlings of black pepper (Piper nigrum L.) contributes to fusarium and nematodes infestation in commercial crops, and thus the usage of alternative substrates might be a preventive control measure against these pathogens. The aim of this study was to investigate the rhizogenic behavior of the cultivars Bragantina, Iaçará and Guajarina of black pepper in different substrates. The experimental design was in randomized blocks in a 3x4 factorial design (cultivars: Bragantina, Iaçará and Guajarina x substrates: soil + organic compound (18%), vermiculite, carbonized rice hulls and commercial substrate), with four replications of 16 cuttings each. The evaluated characteristics were: survival (%); rooting (basal or nodal) (%); nodal rooting (%); basal rooting (%); number of nodal roots; number of basal roots; total number of roots; length of the largest nodal root (cm); basal root length (cm); nodal root volume (cm3); basal root volume (cm3); Total root volume (cm3); nodal root dry mass (mg); basal root dry mass (mg) and the total root dry mass (mg). There are differences within black pepper cultivars as to the characteristics related to the root system. The vermiculite substrate was the most suitable, and carbonized rice hull is not recommended for the adventitious rooting of cuttings of cultivars Bragantina, Iaçará and Guajarina.

Germinação e desenvolvimento de plântulas de girassol ornamental em substratos

The ornamental sunflower is a growing crop in recent years due to its rapid return on investment and expressive representation in the flower market, and research on the ideal substrate for seedling production is essential to maximize information for the crop. Thus, the objective was to evaluate the germination and development of ornamental sunflower seedlings in different substrates compositions. The experiment was installed in a greenhouse, where they were put to germinate, seeds of sunflower type “Vincent’s Choice” in poliestileno trays on substrates with or without addition Slow Release Fertilizer (SRF) at the dose 2 g L-1. The experimental design was completely randomized with 4 treatments [T1- Charcoal + pine bark + peat + expanded vermiculite (1:1:1:1), T2- Coconut fiber + carbonized rice hull + peat + expanded vermiculite (1:1:1:1), T3- Charcoal + pine bark + peat + expanded vermiculite (1:1:1:1) + SRF, T4- Coconut fiber + Carbonized rice hull + peat + expanded vermiculite (1:1:1:1) + SRF] with 8 replicates of 8 seeds, totaling 64 seeds per substrate. It was evaluated: the percentage, index and average germination time, chlorophyll content, length, fresh and dry mass of shoot and root. It was observed that there was no difference in the percentage of germination, but T2 and T4 promoted emergency in the lowest mean time (3.19 and 3.46 days, respectively) with a higher rate of velocity (2.43 and 2.25 respectively), still, T4 presented increments with more than 50% of fresh and dry mass. Thus, it is concluded that the T4 substrate is recommended for germination and development of ornamental sunflower type “Vicent’s Choice”.

Comparison between Carbon Nanotube-Based, Graphite-Based, and Rice Hull Carbon-Based Electrodes with Rice Hull Silica as Catalyst for Electrochemical Detection of Copper

This study aimed to determine the copper ion-sensing ability of a carbon nanotube (CNT)-based sensor with carbonized rice hull (CRH) as catalyst. The 50:50 CNT-CRH electrode was compared to 100% graphite, 100% CRH, 100% CNT, 50:50 graphite-CRH, and 70:30 graphite-CRH electrodes. Copper chloride (CuCl2) concentrations of 0.01M, 0.02M, 0.03M, 0.04M, 0.04M, 0.05M, 0.06, 0.07M, 0.08M, 0.09M, and 0.1M were used to test the response of the electrodes. Five trials were done for each concentration. The 50:50 CNT-CRH electrode exhibited good sensor characteristics such as high sensitivity, low resolution, and high correlation in concentration-voltage relationship. Electrical characterization using three-electrode system showed a linear relationship between the concentrations and voltage response. The 50:50 CNT-CRH electrode exhibited a sensitivity of 0.0619 V/0.01M or 9.7 mV/100ppm and a resolution of 10 ppm/1mV. The electrode also exhibited a high correlation R2 value of 0.933.