Oven-dry Weight Research Articles

Properties of oriented strand boards made from two Indonesian bamboo species at different pressure levels and strand lengths

This study aimed to evaluate the effect of bamboo species, specific pressure, and strand length on the properties of oriented strand boards (OSBs). Laboratory scale OSBs were made from two Indonesian bamboo species [tali (Gigantochloa apus) and andong (Gigantochloa pseudoarundinacea)] with three different strand lengths (75, 100, and 150 mm). For each bamboo species and strand length, OSBs were fabricated by bonding bamboo strands with 7% phenol formaldehyde resin and 0.5% wax emulsion based on their oven-dry weight. The layer structure of the face, core, and back of the three-layer cross-oriented board were 25%, 50%, and 25%, respectively. A specific pressure of 25 or 30 kg/cm2 was applied for 6 min at 160 °C. The targeted OSB density was 0.75 g/cm3. The results showed that OSBs from andong bamboo had better dimensional stability and bending strength than those from tali bamboo. The bending strength of bamboo-based OSBs increased with increased bamboo strand length. A strong interaction was found between bamboo species, specific pressure, and strand length on the mechanical properties of OSBs. The properties of all bamboo-based OSBs produced in this study conform with the requirements of the Japanese Industrial Standard JIS A 5908 (2015) and British Standard BS EN 300 (2006).

The effect of NPK fertiliser on oil palm coefficient as a baseline water management during the nursery phase

The Indonesian government views the oil palm industry as a promising sector for poverty alleviation. The germination process of seeds is influenced by water, requiring careful management. This study investigated the impact of NPK application and NPK fertiliser on the crop coefficient value of Tenera variety oil palm seedlings. The entisol soil used had a sandy clay texture, with sand comprising 81.00% of the soil composition. The soil texture, organic matter, bulk density, particle density, porosity, evapotranspiration, potential evaporation, percolation, moisture content at field capacity, and oven-dried root weight were measured with and without fertiliser to 50 oil palm trees at 3 to 6 months of age. The results show that NPK application has affected oil palm’s crop coefficient and growth. The highest dry root weight and plant coefficient obtained without fertiliser and with fertilisers at six months were 24.76 gr and 33.89 gr, 0.626 and 0.65, respectively. Root biomass, a sign of plant health and nutrient uptake, shows fertilization’s long-term effects. Six-month-old plants, especially fertiliser ones, have more extensive root dry weights, indicating persistent nutrition uptake and long-term resistance. Nutrient management is crucial to agricultural productivity, affecting the current crop and future growth phases.

Durability to Natural Weathering of Methylene Diphenyl Diisocyanate-Bonded Bamboo Oriented Strand Board

This study aimed to examine the qualities of bamboo-oriented strand board (BOSB) made from Dendrocalamus asper bamboo strands, both with and without steam treatment. Furthermore, the effect of exposure length to natural weathering on the physical and mechanical characteristics of BOSB was examined. The steam treatment lasted one hour at 126°C and a pressure of 0.14 MPa. Methylene diphenyl diisocyanate (MDI) and paraffin were utilized as adhesives and additives, with concentrations of 5% and 1%, respectively, based on oven-dried weight. The BOSB was exposed to natural weathering in different exposure durations (0, 1, and 3 months) in Bukit Bogor Raya Pajajaran, West Java, Indonesia. Subsequently, the BOSB was tested for its physical and mechanical properties and retention value. The result showed that steam treatment improved the dimensional stability and mechanical properties of BOSB bonded with MDI adhesive more than untreated BOSB. However, steam treatment has a better protection level against natural degradation than untreated samples. These confirm that BOSB with steam treatment is a durable and sustainable construction material. Keywords: bamboo, methylene diphenyl diisocyanate, natural weathering, oriented strand board, steam treatment

The initiation of smouldering peat fire by a glowing firebrand

Background Wildfires represent a significant threat to peatlands globally, but whether peat fires can be initiated by a lofted firebrand is still unknown. Aims We investigated the ignition threshold of peat fires by a glowing firebrand through laboratory-scale experiments. Methods The oven-dried weight (ODW) moisture content (MC) of peat samples varied from 5% ODW to 100% ODW, and external wind (ν) with velocities up to 1 m/s was provided in a wind tunnel. Key results and conclusions When MC < 35%, ignition is always achieved, regardless of wind velocity. However, if MC is between 35 and 85%, an external wind (increasing with peat moisture) is required to increase the reaction rate of the firebrand and thus heating to the peat sample. Further increasing the MC to be higher than 85%, no ignition could be achieved by a single laboratory firebrand. Finally, derived from the experimental results, a 90% ignition probability curve was produced by a logistic regression model. Implications This work indicates the importance of maintaining a high moisture content of peat to prevent ignition by firebrands and helps us better understand the progression of large peat fires.

Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia

Abstract. Anna N, Siregar IZ, Supriyanto, Sudrajat DJ, Karlinasari L. 2023. Physical, mechanical, and anatomical properties of 12 jabon (Neolamarckia cadamba) provenances wood in Indonesia. Biodiversitas 24: 5895-5904. Jabon is a raw wood material for paper industries and has a fast-growing ability. Comprehensive information on the fundamental qualities of wood from the 12 provenances of jabon (Neolamarckia cadamba (Roxb.) Bosser) is a critical aspect of understanding their superior properties. The age of the samples at the trial was 42 months old, and the number of trees tested was 12, representing one provenance. Wood samples for physical (disk samples), mechanical, and anatomical properties were sampled at a height and length of 1.3 m and 35 cm. The logs were divided into 5 cm and 30 cm for wood samples with anatomical and mechanical properties. The physical and mechanical properties were tested according to ASTM D 4442, ASTM D 2395, and ASTM D 143 standards. The physical (density, specific gravity, and moisture content), mechanical properties (MOE and MOR), and anatomical properties (fiber length and microfibril angle) were carried out on wood from 12 provenances. Physical and anatomical properties were tested, from the pith to the outer bark. The average green wood density was 0.94 gcm-3, while the highest was obtained in the Rimbo Panti, Nusakambangan, Kapuas Tengah, and Batu Hijau provenances. The average specific gravity value from the 12 provenances of jabon was 0.46 in Batu Licin and Batu Hijau provenances; the average moisture content on oven-dry weight was 105.13%; and the highest value was in the Kuala Kencana provenance. The average MOE and MOR values were 51,039.93 kgcm-² and 488.37 kgcm-², with a dry air moisture content of 13.62%. The highest MOE and MOR values were in the Batu Licin and Gowa provenance, with MFA testing varied at 11.54°. The fiber length from the pith to the outer bark tended to increase, with an average of 1183.28 ?m. Based on the value of physical, mechanical, and anatomical properties, 12 provenances of jabon can only be used as non-structural raw materials. The Batu Hijau provenances have the highest density and specific gravity. However, the highest fiber length was found in Gowa provenance.

Combined influence of ash and poultry manure on soil reaction and performance of maize (<i>Zea mays</i>) in a coarse-textured acid soil of South-East, Nigeria

Crop production can be limited by soil acidity. A two-factor factorial experiment involving three levels each of ash and poultry manure (PM) was conducted to determine the effects of ash and PM on soil reaction and performance of maize in an acid soil. The ash comprised of mixture of ash from wood, cocoa husk and palm bunch. The levels of ash (0.00, 3.00, 6.00 t ha–1 ) and PM (0.00, 4.00, 8.00 t ha–1 ) were combined to obtain nine treatment combinations (control, 3.00 ash and 0.00 PM, 3.00 ash and 4.00 PM, 3.00 ash and 8.00 PM, 0.00 ash and 4.00 PM, 3.00 ash and 0.00 PM) which were replicated thrice. The experiment was laid out in a randomized complete block design. Soil samples were collected at 3, 6, 9 and 12 weeks after planting (WAP), plant height measured at 3, 5, 7, and 9 WAP while cob oven-dry weight was measured after oven-drying harvested cobs at maturity. Analysis of variance was conducted on the data collected using GenStat version 14. The highest plant height of 132.50 cm at 12 WAP and the highest oven-dry cob weight of 7.15 t ha–1 were obtained from plots treated with 6.00 and 8.00 t ha-1 of ash and PM, respectively, and these were significantly (p ≤ 0.05) different from the other treatments. The lowest exchangeable acidity of 1.33 cmol kg–1 which varied significantly (p ≤ 0.05) from the other values observed at the other plots was obtained at the plot treated with the combination of 6.00 and 4.00 t ha–1 of ash and PM, respectively at 12 WAP. The combination of ash and PM at 3.00 and 8.00 t ha–1 gave the highest pH of 6.80, and this was significantly (p ≤ 0.05) different from the other treatments. Therefore, ash and PM at varying levels of combination can simultaneously ameliorate soil acidity and improve maize performance; however, the best combination of ash and PM application which showed the potential to produce optimum effect in simultaneously ameliorating soil acidity and increasing maize performance was the combination of 6.00 tonnes of ash and 8.00 tonnes of PM.

Evaluation of the biomass, carbon sequestered and microbiota in a naturally-growing Bambusa vulgaris. Schrad. Ex J.C. Wendl stand

The world is increasingly facing the conflicting pressures of economic growth and environmental protection, and forests have the capacity to sequester carbon from the atmosphere in large amounts. This study evaluated the biomass, carbon content and microbial activities of a naturally growing Bambusa vulgaris stand at the Forestry Research Institute of Nigeria (FRIN), Ibadan, Oyo state. Three clumps were randomly selected for the study and analyzed to obtain the biomass, carbon content and microbial population. After harvesting, the culm samples were divided into leaf, branch and culm components and their respective fresh weights were taken. All the sub-samples were then oven-dried at 65 °C for 48 h and to get the oven-dried weight, a ratio of oven-dry to fresh weight was calculated. The total stand biomass for B. vulgaris was then determined and computed on a per hectare basis, while the microbiota were determined using standard methods. The B. vulgaris stand stored in total 59.37 t/ha carbon of which 30.55 t/ha were stored in the above-ground biomass (culms, branches and leaves), 1.53 t/ha in the below ground biomass and 24.29 t/ha in the soils. The total biomass stored by the stand was 59.42 t/ha, of which 56.59 t/ha was stored above ground and 2.83 t/ha in the below-ground biomass. Total biomass carbon content in B. vulgaris was 32.08 t/ha. The aboveground carbon storage was much higher in culms (16.69 t/ha) than in branches (8.52 t/ha), leaves (5.32 t/ha), in litter fall (0.02 t/ha) or rhizomes (1.53 t/ha). The total soil carbon content was 24.29 t/ha, of which 8.48 t/ha occurred at 0–15 cm depth, 8.19 t/ha at 15–30 cm, and 7.62 t/ha at 30–45 cm depth. A regression model was developed for future predictions of carbon content of B. vulgaris. About 16 microorganisms were identified in the study (10 bacteria and 6 fungi species) with populations ranging with soil depth. The amount of carbon sequestered and the short time needed for bamboo to grow makes it a good carbon sink, thereby helping to mitigate climate change issues.

Pengaruh Pupuk Organonitrofos dan Volume Irigasi Terhadap Pertumbuhan Mint (Mentha piperita L.) Organik

Mint (Mentha piperita L.) is one of the aromatic herbs. The aim of this research was to investigate the effect of organonitrophos (organic fertizer) and irrigation water volume on the growth and yield of organically cultivated mint. The experiment was conducted in a completely randomized design (CRD) with two factors, namely the dose of organonitrophos consisting of 4 levels: D0 (0%), D1 (10%), D2 (30%), and D3 (50%) of the total weight of the media, and irrigation volume consisting of I1 (20-40%), I2 (50-70%), and I3 (80-100%) of the field capacity. The results showed that the dose of organonitrophos fertilizer and irrigation water volume affected the growth and yield of mint. The treatment that statistically produced the highest oven-dried weight (18.67 grams per plant) was D3I2 (50% compost fertilizer and 50-70% irrigation water). The treatment that produced the highest fresh weight (104.7 grams per plant) and was the most efficient was D2I1 (30% compost dose and 20-40% irrigation water). However, as a consequence, the choice of D2I1 significantly reduced the weight of oven-dried yield to 13.33 grams per plant. Keywords: Organic, Mentha, Piperita, Organonitrofos, Irrigation

Effect of Lignin-Rich Microfiber on Handsheet Strength

This study explores the effects of using lignin-rich microfibers as a reinforcing material to enhance paper strength. The microfibers prepared by alkaline kneading of organosolv pulp for 1 to 3 hours were characterized in terms of fiber dimensions, residual lignin content, freeness, and water retention value. Longer alkaline kneading times were more effective for improved fiber micronization. In addition, freeness decreased and water retention value increased as a result of the kneading treatment. The microfibers were added at increasing amounts (1%, 3%, and 5% based on oven-dry weight) to commercial bleached kraft pulp to evaluate the effect of microfiber content on handsheet strength. The results showed that microfibers at a level of 5% increased the tensile index of the handsheet by up to 8%, indicating that lignin-rich microfibers have a high potential for use as paper strength additives.

Influence of Isocyanate Content and Hot-Pressing Temperatures on the Physical–Mechanical Properties of Particleboard Bonded with a Hybrid Urea–Formaldehyde/Isocyanate Adhesive

Particleboard (PB) is mainly produced using urea–formaldehyde (UF) adhesive. However, the low hydrolytic stability of UF leads to poor water resistance by the PB. This research aimed to analyze the effect of hot-pressing temperatures and the addition of methylene diphenyl diisocyanate (MDI) in UF adhesive on the physical and mechanical properties of PB. The first experiment focused on pressing temperature treatments including 130, 140, 150, and 160 °C. The particles were bonded using a combination of UF and MDI resin at a ratio of 70/30 (%w/w). Furthermore, the second experiment focused on UF/MDI ratio treatment, including 100/0, 85/15, 70/30, and 55/45 (%w/w), and the particles were pressed at 140°C. All of the single-layer particleboard in this research were produced in 250 × 250 mm, with a target thickness and density of 10 mm and 750 kg/m3, respectively. This research used 12% resin content based on oven-dry weight wood shaving. The pressing time and pressing pressure were determined to be 10 min and 2.5 N/mm2, respectively. Before the tests, the board was conditioned for 7 days. When studying the effect of treatment temperature, good physical properties (thickness swelling and water absorption) and mechanical properties (MOR and MOE) were obtained at 140 °C. However, no significant difference was observed in the UF/MDI ratio between 85/15 and 55/45 using the same temperature. The increase in the MDI adhesive ratio improves the MOE and MOR values. However, the internal bond was the contrary. This study suggests that a combination of UF/MDI at a ratio of 85/15 and hot-pressing temperature at 140 °C could produce a PB panel that meets a type 8 particleboard according to the JIS A5908-2003 standard and type P2 according to the EN 312-2010 standard.

The Effect of Compost and Biochar Fertilizers on The Growth and Yield of Shallots

This study aims to determine the effect of compost and biochar doses and their interactions on the growth and yield of shallots. This research was conducted at the Local Waste Processing Site (TOSS), Kusamba Village, Dawan District, Klungkung Regency, Bali Province. The design used in this study was a factorial randomized block design (RAK) consisting of 2 factors. The first factor is the treatment of compost dose (K) which consists of 3 levels, namely: K1 = 5 tons ha-1, K2 = 10 tons ha-1, and K3 = 15 tons ha-1. While the second factor is the dose of biochar (B) which consists of 3 levels, namely: B1 = 5 tons ha-1, B2 = 10 tons ha-1, and B3 = 15 tons ha-1. The interaction between compost treatment with biochar had a significant (P<0.05) effect on the fresh weight of tubers per clump and fresh weight of rhizomes per clump, and a very significant effect (P<0.01) on the number of tubers per clump, but not significant (P≥0.05) to other variables. The compost dose treatment had no significant effect (P≥0.05) on all observed variables except for the maximum number of leaves. Biochar dose treatment had a significant to a very significant effect on the variables of maximum leaf number, fresh weight of tubers per clump, the oven-dry weight of tubers per clump, and oven-dry weight of tubers per clump, and had no significant effect (P≥0.05) on other variables. The interaction between compost 5 tons ha-1 and biochar 10 tons ha-1 (K1B2) gave the highest fresh weight of tubers per clump of 100.00 g which was significantly different or increased by 38.60% compared to the lowest fresh weight of tubers per clump at the interaction of compost 5 tons ha-1 with biochar 15 tons ha-1 (K1B3) is 72.15 g.

Pengaruh Residu Pemberian Abu Vulkanis Gunung Agung dan Pupuk Kompos terhadap Tanah dan Tanaman Kacang Tanah (Arachis hypogaea L.)

Residual Effect of Mount Agung Volcanic Ash and Compost on Soil and Peanut Plants (Arachis hypogaea L.). Research on the application of Mount Agung volcanic ash and compost has been carried out with cowpea as an indicator plant, but volcanic ash has not shown any effect. The volcanic ash of Mount Agung is in the form of material that has not been weathered, so to accelerate weathering it is necessary to add organic matter. The purpose of this study was to determine the residual effect of giving volcanic ash and compost on soil and peanut plant. The design used was a factorial randomized block design with 3 replications. The volcanic ash factor consists of 3 levels, namely A0 = no volcanic ash, A1 = 10% volcanic ash and A2 = 30% volcanic ash. The compost factor consists of 3 levels, namely K0 = without compost, K1 = 10 tons of compost ha-1, and K2 = 20 tons of compost ha-1. Parameters of soil properties observed were : total porosity, nitrogen, phosphorus and potassium content and C-organic matter content. Observation of peanut plants included : plant height, number of pods, weight of oven-dried pods, weight of oven-dried seeds and weight of oven-dried peanut stem. The results of research showed that there was no interaction between the treatment of volcanic ash residue and compost residue on the soil and peanut plants, while the single treatment of compost residue had a significant effect on peanut plants. The treatment of volcanic ash residue has not shown a significant effect, both on the soil and on peanut plants.

"EFFECTS OF DIFFERENT RATIOS OF STARCH-CONTAINING AKD ON PAPER PROPERTIES IN INTERNAL SIZING OF VARIOUS PULP TYPES "

The main objective of this study is to determine the effects of different ratios of starch-containing AKD emulsion in various pulp types sizing processes on paper properties. A secondary objective of the study is to evaluate the influences of starch content in AKD emulsion and AKD dosage applied to pulps. Three different pulp types were sized: unbleached kraft, bleached kraft and chemithermomechanical pulps. In preparation of AKD emulsions, three different ratios of starch were used. AKD was applied to all pulps under the same conditions at four different dosages based on oven-dried fiber weight. Test papers were produced and Cobb values (water absorptiveness), some mechanical and optical properties of the papers were determined. In addition, SEM, XRD and contact angle analyses were applied to papers produced with optimal sizing parameters. As a result of the study, it was found that the effects of AKD cause different behaviors depending on the pulp types. AKD was highly efficient in sizing chemithermomechanical pulp, decreasing the Cobb value by 90.9%. Depending on the pulp type, the starch content used in the emulsion preparation and the AKD dosage applied to the papers have various effects on the paper properties.

Moisture Absorption Behavior of CP5 Composite Materials Used in Industry

In engineering practice, perhaps the most interesting aspect of woodworking deals with the relationship between wood and moisture. The plywood composite presents hygroscopicity characteristic, as the wood and reaction almost like a sponge, will gain or lose moisture from the air based upon the conditions of the surrounding environment. When the tree is in the green state, is first felled, it contains a very large amount of moisture existing in two different forms: as free water that is contained as liquid in the pores or vessels of the wood itself and as bound water, trapped within the cell walls. After that the wood is exposed to the air and immediately loose free water and the wood does not contract or otherwise change in dimension, it is in the state of drying and it is called the fiber saturation point. The moisture content in each piece of CP5 composite material is expressed as a percentage of the weight of the water and oven-dry weight of CP5 composite material. The moisture absorption depends on the wood type, density of wood and it is influenced by the environmental temperature, this is an aspect very important in the furniture industry. The moisture absorption test is generally used for quality control purposes and to measure the degradation of the quality for the wood and composite materials.

SOME PHYSICAL AND MECHANICAL PROPERTIES OF KATHBADAM (Terminalia catappa Linn.) WOOD OF BANGLADESH

The present study was undertaken to represent mainly some strength properties of kathbadam (Terminalia catappa Linn.) wood of Bangladesh along with finding out some relevant physical properties of the same. The research works were carried out following standard test methods comparing the findings with those of standard Chittagong teak (Tectona grandis L.f.) reported earlier. The longitudinal, radial, tangential and volumetric shrinkages of T. catappa wood from green to oven-dry conditions were found 0.64%, 2.71%, 5.08% and 8.43% respectively. The specific gravity of the wood species based on oven-dry weight by green volume and oven-dry weight by oven-dry volume were found 0.46 and 0.52 respectively. The green moisture content of T. catappa wood was found 92.51%. Regarding green mechanical properties, the fibre stress at elastic limit and modulus of rupture was found 408.61 and 666.16 kg cm-2 respectively. Similarly the revealed green compressive strength parallel to grain at elastic limit and at maximum load was 210.54 and 273.74 kg cm-2 respectively. The green tensile strength parallel to grain at maximum load was revealed 438.41 kg cm-2. At the same moisture conditions the screw withdrawal capacity was determined 187.16 kg at sawn face and 170.53 at edge. All these properties of T. catappa wood were found relatively and reasonably lower than those of Chittagong teak.

RESPON TANAMAN SELEDRI (APIUM GRAVIOLENS L.) TERHADAP PEMBERIAN PUPUK BOKASHI PADA UMUR BIBIT YANG BERBEDA

The purpose of this study was to determine the effect of bokashi fertilizer dose and seedling age and their interaction on the growth and yield of celery plants. This research was conducted in Banjar Candikuning 2, Candikuning Village, Baturiti District, Tabanan with an altitude of 1255 m above sea level. The study was conducted from November 22, 2021 to January 26, 2022. This research is a pot experiment using a basic design, namely Randomized Block Design with a factorial pattern. The treatments given were the dose of bokashi fertilizer and the age of the seedlings, each treatment was repeated three times.The interaction between bokashi fertilizer dose treatment and seedling age (N x U) had a very significant effect (P < 0.01) on most of the observed parameters, except for the oven dry weight of the top of the plant, oven dry weight of the bottom of the plant and oven dry weight. total plants that showed no significant effect (P 0.05). The highest total plant fresh weight was obtained at a dose of 1.0 kg of bokashi fertilizer at the age of 25 days after seedling (N2U1) of 7.40 g, an increase of 482.67% from the lowest yield of treatment with a dose of bokashi fertilizer without fertilizer at the age of 30 seeds. hss (N0U2) which is 1.27 g.Bokashi fertilizer treatment with a dose of 1.0 kg (N2) gave the highest total plant oven dry weight of 0.44 g, while the lowest was obtained in the treatment without fertilizer (N0) only 0.09 g or an increase in yield of 388.89 %. The seedling age treatment gave the highest total oven dry weight of the plant at the seedling age of 25 hss (U1) which was 0.35 g or an increase in yield of 45.83% compared to the 30 hss (U2) seedling age treatment which gave the total oven dry weight of the plant only. of 0.24 g

Representing vapour and capillary rise from the soil improves a leaf litter moisture model

• Soil water affects litter moisture predictions. • Vapour and capillary rise from the soil were represented to estimate litter moisture. • Models ignoring soil water effects underestimated litter moisture. • Hydraulic coupling between the litter and soil is important. Litter moisture content plays a critical role in fire danger rating systems and forest ecosystems. Soil moisture content has been proposed to affect litter moisture due to vapour flux and capillary rise from the soil. However, few models consider soil water content when predicting litter moisture, and to our knowledge, no model includes capillary fluxes. In this study, we represented soil moisture coupling in a physics-based litter moisture prediction model by describing the vapour and capillary fluxes from the soil to litter. We aimed to evaluate if litter moisture predictions can be improved by incorporating the hydrological process at the soil-litter interface and explored the possible role of soil moisture in litter moisture simulations. Three model versions were compared against observations at a dry and wet experimental site in Australia: the original physics-based model, a model version extended with soil vapour flux only, and a version that incorporates both soil vapour flux and capillary rise. The simulation results suggest that soil moisture considerably influences litter moisture through soil vapour flux and capillary rise, which can lead to more than 10% of oven-dried weight, particularly under wet soil conditions. The corresponding model showed the best performance in comparison with field observations. The contribution of upward soil moisture fluxes was small after long dry and warm periods but noticeable during more moist periods. Further research is needed to evaluate the revised model for a broader range of weather, soil and litter conditions.

How to take volume-based peat samples down to mineral soil?

Determination of soil organic carbon stocks in peat soils is of major importance for prioritization and evaluation of mitigation measures. This requires the accurate assessment of bulk density, which is commonly undertaken by measuring the oven-dry weight of a volume-based sample. Sample rings (steel cylinders) are widely used and have become the method of choice. If sample rings cannot be taken (e.g. in deep peat layer), sampling needs to be performed with other sampling devices. The aim of this study is to evaluate the accuracy and precision of different sampling devices in determining bulk density and total peat masses of the entire peat profiles down to mineral soil. Four sampling devices (driving hammer device with a sheath probe, gouge auger, Russian corer and Wardenaar corer) were compared with sample rings at one bog peat site and one fen peat site. The gouge auger and Russian corer – the only sampling devices in this study applicable for depths below approximately −1m – were also compared with one another.The results varied depending on peat type and horizon characteristics. Sample rings and the driving hammer were the only sampling devices that could be used to sample the amorphous or aggregated peat of the upper, unsaturated part of the profiles. However, samples taken with the driving hammer significantly underestimated bulk densities and thus caused a high systematic error of −0.068 g cm−3. In the sampling depths with slightly to moderately decomposed peat, bulk density values determined with the driving hammer, gouge auger and Wardenaar corer were not significantly different from the data acquired using sample rings. At these depths, all the sampling devices had low systematic errors, with −0.002 g cm−3 for the gouge auger, 0.005 g cm−3 for the driving hammer, −0.006 g cm−3 for the Wardenaar corer and 0.012 g cm−3 for the Russian corer. The Russian corer caused an overestimation of bulk density in the unsaturated sampling depths, whereas in the saturated sampling depths, the values were similar to those determined with the gouge auger. Total peat masses determined using the tested sampling devices differed only slightly. As those devices which can acquire samples from the amorphous or aggregated horizons are not suited for deep peat profiles, a combination of different devices will be necessary for determining bulk density and thus soil organic carbon stocks at many peatland sites. We could show that this is a reliable approach when considering site-specific conditions.

Arabica Coffee Growth Response on Composting Time Treatment and Coffee Skin Biochar Dosage

This study aims to determine the effect of composting time, biochar dose, and the interaction between composting time and biochar dose on the growth of Arabica coffee seedlings. This research was conducted at UPP Arabica Coffee Plantation. Catur Paramitha in Catur Village, Kintamani District, Bangli Regency, Bali Province. The altitude of the place is between 1,250 meters above sea level. The time of the research was carried out from September to December 2021. This study used a Randomized Block Design (RAK) with 2 factors arranged in a factorial manner. The first factor is the time of composting of wet coffee skin waste material which consists of 2 levels, namely P1 = 2 weeks of composting and P2 = 4 weeks of composting. The second factor is the dose of biochar as raw material for dried coffee cherries, consisting of 4 levels, namely, B0 = control, B1 = 5 tons/ha, B2 = 10 tons/ha and B3 = 15 tons/ha thus obtained 8 repeated combination treatments. 3 times so 24 plants are needed. The variables observed were plant height, number of leaves per plant, stem diameter, plant leaf area, root fresh weight per plant, stem fresh weight per plant, leaf fresh weight per plant, stem, and leaf fresh weight per plant, and total fresh weight per plant. and total oven-dry weight per plant. The treatment with 4 weeks of composting gave the highest total fresh weight per plant, which was 10.43 g, which increased by 11% when compared to the treatment with 2 weeks of composting, which was 9.44 g. The treatment with a dose of 15 tons/ha of biochar gave the highest total fresh weight per plant, which was 10.45 g, which increased by 13% when compared to the treatment without biochar, which was 9.27 g. The interaction of 4 weeks of composting with a dose of 15 tons/ha of biochar (P2B3) gave the highest total fresh weight yield per plant of 11.73 g which increased by 24% when compared to the interaction of 2 weeks of composting without biochar (P1B0) which was 9.4g.

Effect of Decomposed Fruit Waste on the Growth and Biomass Production of Red Amaranth (Amaranthus cruentus)

This study attempts to observe the effect of decomposed fruit waste on the growth and biomass production of red amaranth (Amaranthus cruentus). Decomposed fruit waste used as organic fertilizer to ensure soil health. Besides, the use of organic fertilizer instead of using toxic chemical fertilizer is an alternative eco-friendly approach. In this experiment, compost was prepared by using banana and orange peel wrapped in two different poly bags and kept them for 6 months under the soil. Here five treatments and three replications were used in which 1000 kg ha1 and 2000 kg ha-1 orange peel and banana peel composts were used as treatments. Red amaranth was grown as a test crop. After harvesting plants, different growth parameters such as shoot length, root length, leaf number, fresh weight, oven-dry weight and percent of moisture content were measured. The results exhibited that all growth parameters increased significantly by the application of decomposed fruit wastes. However, the application of 2000 kg ha-1 decomposed orange peel performed better in all respects. South Asian J. Agric., 8(1&2): 1-5