Corg Content Research Articles

Biofertilizer gel contains Phosphate Solubilizing Microbes (PSMs) plus and its effect on phosphate dynamics in Inceptisols Jatinangor-Indonesia

Dependence on inorganic fertilizers is a major risk in today's food supply efforts, along with the increasing population. One of the efforts to reduce this risk is to apply biological fertilizers that are specially formulated on the suitable carrier material so that they are able to work effectively and efficiently in substituting the need for inorganic fertilizer inputs and increasing plant yield components. Inceptisol series Jatinangor has characteristic soil texture is dominated by clay fraction, neutral pH 7.01. Under neutral conditions, in general, nutrients in the soil tend to be more readily available, but the availability of P is actually very low at only 2.82 mg.kg-1 of soil. In this neutral to alkaline pH, the solubility of metal cations Ca and Mg increased, indicated by a high Ca2+ content of 12.60 cmol.kg-1 and Mg2+ which was also high at 4.91 cmol.kg-1. The nutrient imbalance is also due to the low C-organic content of the soil, namely 1.83%, so that the soil's support capacity is low. Low organic C causes the presence of indigenous microbes which is quite high, especially PSMs, namely 1 x 104 cfu.g-1, which is not able to increase the availability of soil nutrients, especially P due to lack of carbon sources. The experiment aimed to determine the compatibility and characteristics of inoculants in the biofertilizer gel contains PSMs plus (BG) and its effect on the dynamics of phosphate in Inceptisols Jatinangor. BG contains a consortium of phosphate solubilizing bacteria (PSB) and phosphate solubilizing fungi (PSF) which are packaged in hydrogel carriers and additives. The PSB used were Bacillus subtillis, Pseudomonas maleii, and Bulkholderia cepacea, while the PSF used was Trichoderma asperellum. The experiment were carried out in vitro at the Soil Biology Laboratory of Universitas Padjadjaran in collaboration with PT Agritek Tani Indonesia and at the Experimental Land of the Department of Soil Science of Universitas Padjadjaran. The experimental design used in this study was a single randomized block design (RBD) with 9 treatments and 3 replications, consisting of treatments (control: 0 BG + 0 P); (1 P); (1 BG); (1 BG + ½ P); (1 BG + ¾ P); (1 BG + 1 P); (½ BG + ¾ P); (¾ BG + ¾ P); and (1 ½ BG + ¾ P). The dose of fertilizer used was BG 50 kg. ha-1, SP-36 100 kg.ha-1, Urea 350 kg.ha-1, KCl 50 kg.ha-1, and sheep manure as basic fertilizer 2 t.ha-1.The results showed that each isolate had the ability to dissolved phosphate, produced IAA, and one of them was antagonistic against the fungal pathogen Fusarium sp.. The combination of fertilizers had an effect on regulate soil pH, and increasing phosphatase activity, soil available P, soil potential P, and PSMs population in the soil. The formulation of 1 BG + ¾ P consistently showed the best effect on soil phosphate dynamics in Inceptisols Jatinangor.

HUBUNGAN C-ORGANIK TANAH TERHADAP SIFAT FISIK TANAH PADA PERTANAMAN SAWI PAKCOY DI DESA WOLOFEO KECAMATAN DETUSOKO KABUPATEN ENDE

The production of mustard pakcoy (Brassica rapa L.) depends on the level of soil properties. Therefore, a study was conducted to determine the physical and chemical properties of the soil for mustard cultivation and its relationship. This research is quantitative descriptive. Observation variables in this study were C-organic soil, soil texture, soil moisture content, porosity, and bulk density. Laboratory data from soil physical properties and C-organic soil were matched with soil chemical criteria and evaluation of land suitability, After that, correlation analysis is used to see the relationship. The results showed that the C-organic content of the soil in Wolofeo Village was 3.01%-3.54% and was classified as high. While the physical properties of the soil in Wolofeo Village are for soil moisture content ranging from 39.77% -41.11%, Porosity ranges from 52.42% -61.33%, Fill Density ranges from 1.02 -1.26 g/ cm3, and the soil texture is sandy loam. These criteria are very suitable conditions for the cultivation of mustard greens. The relationship between C-organic soil and soil physical properties shows a significant relationship.

Loss of surficial sedimentary carbon stocks in seagrass meadows subjected to intensive clam harvesting

Seagrass carbon stocks are vulnerable to physical disturbance. We assessed the effect of clam harvesting on the organic carbon (Corg) stocks in surface sediments in four intertidal Zostera noltei meadows on the Iberian Atlantic coast (Spain and Portugal), by comparing undisturbed and harvested areas. We also monitored the spatial cover of the meadows throughout the growing season. Sedimentary Corg content and Corg stocks were about four times lower in intensively harvested areas than in control areas, but there were not differences between areas with low harvesting pressure and control areas. Reductions of 53–85% in sedimentary Corg stocks of Z. noltei meadows were caused by intensive clam harvesting. The effect of intensive clam harvesting on Corg stocks increased throughout the growing season, but the area covered by the seagrass increased from 21 to 37%, suggesting rapid recovery of seagrass canopies and potential recovery of sedimentary Corg stocks.

Cattle Manure Fermented with Biochar and Humic Substances Improve the Crop Biomass, Microbiological Properties and Nutrient Status of Soil

Co-composting of raw manure with other organic sources has recently gained the attention of the scientific community. In the present study, raw manure and manures enriched with humic substances (Humac) or biochar were co-composted to improve their physico-chemical properties. We conducted an experiment including variants consisting of soil amended with manure (M), manure + Humac (M + H), manure + biochar (M + B), and unamended (control). Soil physico-chemical, biological, and plant properties were assessed altogether. All matured manures differed from each other physico-chemically (nutrient content) and in microbial composition, and hence their effects on the observed parameters. Compared to control, the soil respiration and enzyme activities related to N and P mineralization were enhanced due to the amendment of either manure or enriched manures. The M + H treatment resulted in higher pH of the manures as compared to other treatments, whereas the M + B and M treatments revealed the highest Corg contents of the final product, which was negatively correlated with HA:FA. In the same manner, M + H and M + B were the most prominent treatments, causing higher variations in basal soil respiration. The same treatments resulted in the highest percent increase values of soil enzymes related to C, N, and P, which further show the potential of manure modification as a viable option to boost soil fertility and health.

ANALISIS KANDUNGAN UNSUR HARA MAKRO PADA MEDIA PERTUMBUHAN JAMBU BOL VARIETAS GONDANGMANIS (Syzygium malaccensei) DI DESA GONDANGMANIS KECAMATAN BANDARKEDUNGMULYO JOMBANG

Gondangmanis guava production has decreased every year, this is due to pests and plant diseases and due to decreased land quality, either due to soil fertility or the absence of cultivation techniques applied to Gondangmanis guava plants. This is caused by several factors, including the lack of supply of agricultural production inputs, the absence of development of guava cultivation technology, the absence of post-harvest technology assembly for guava, and the absence of wider marketing of guava production. soil organic matter, physical properties and macronutrients contained in the land of gondangmanis guava growth. The decline in land productivity will affect the productivity of crop production. Based on this, the author intends to examine how much macro nutrients are available in the Gondangmanis guava growth medium and the soil characteristics of the Gondangmanis guava growing media. The survey and sampling were carried out in the village of Gondangmanis Badarkedung, Mulyo, jombang. Anali This study used a qualitative research using a survey system followed by random sampling of soil at a depth of 0-20 cm. The soil sample is then analyzed in the Integrated Laboratory of the Department of Agriculture. Some of the parameters studied were soil pH determined by a pH meter, N-total was determined by the Kjeldahl method, P-total was determined using the Olsen method, C-organic was determined by the Walkley and black methods. The results of the analysis showed that the chemical content of the soil on the Gondangmanis guava media showed that the soil pH was neutral – alkaline, the C-organic content was very low, the N-total was very low, and the P-total was very high. The soil character of Gondangmanis guava growth media in Gondangmanis village is sandy loam and tends to be sandy.

PENGARUH DOSIS KOMPOS TONGKOL JAGUNG TERHADAP PERTUMBUHAN DAN PRODUKSI BAWANG MERAH (Allium ascalonicum (L.))

This study aims to determine the effect of the dose of corncob compost on the growth and production of shallots. The research was conducted in Pateguhan Village, Pasuruan Regency from January to April 2021. The soil used had a pH of 5.8 with a c-organic content of 2.41%, N-total 0.17%, P2O5 38.46 ppm, and K2O 0.80 ppm. This study was arranged in a one-factor randomized block design (RBD) with six replicates with the following treatment with doses of corncob compost: P0 = control, without corncob composting P1 = treatment with compost at a dose of 10 tons.ha-1 P2 = treatment giving compost at a dose of 15 tons.ha-1 P3 = treatment with compost at a dose of 20 tons.ha-1. The data obtained from the study were analyzed using analysis of variance (F test), if there was a significant effect, then continued with the 5% level BNT test. The results showed that the dose of corncob compost treatment had an effect on the growth and yield of shallots. Treatment of corn cobs compost at a dose of 20 tons.ha-1 gave the highest yield on the observation of growth components, growth analysis and yield components. Treatment of corncob compost at a dose of 20 tons.ha-1 produced a tuber weight of 8.74 tons.ha-1, at a dose of 15 tons.ha-1 corn cobs compost treatment produced a tuber weight of 6.49 tons.ha-1, at a dose of 10 ton.ha-1 corn cobs compost treatment yielded tuber weight of 5.26 ton.ha-1 and the lowest yield was found in the control treatment with yield of 4.17 ton.ha-1.

ANALISIS SIFAT KIMIA TANAH PADA LAHAN HORTIKULTURA DI DESA LADOGAHAR KABUPATEN SIKKA

Soil is one of the main components that affect agricultural productivity. Soil quality certainly needs to be considered as an effort to increase plant growth and production. One of the most influential components of soil quality is the chemical nature of the soil. Research on Analysis of Soil Chemical Content in Horticultural Farmers' Land in Ladogahar Village, Nita District, Sikka Regency has been carried out from October to December 2021. The purpose of this study was to determine the chemical content of the soil in Horticultural Farmers' Land in Ladogahar Village, Nita District, Sikka Regency. This research uses observation methods, literature studies, and laboratory tests. Composite soil sampling using the zigzag method. The results showed that the land had a low C-organic content (1.00-2.00%), a slightly acidic pH (5.6-65), a low phosphorus content (21-40), and a Potassium content in the soil. moderate range (21-40).

Methane Emissions From Nordic Seagrass Meadow Sediments

Shallow coastal soft bottoms are important carbon sinks. Submerged vegetation has been shown to sequester carbon, increase sedimentary organic carbon (Corg) and thus suppress greenhouse gas (GHG) emissions. The ongoing regression of seagrass cover in many areas of the world can therefore lead to accelerated emission of GHGs. In Nordic waters, seagrass meadows have a high capacity for carbon storage, with some areas being recognized as blue carbon hotspots. To what extent these carbon stocks lead to emission of methane (CH4) is not yet known. We investigated benthic CH4 emission (i.e., net release from the sediment) in relation to seagrass (i.e. Zostera marina) cover and sedimentary Corg content (%) during the warm summer period (when emissions are likely to be highest). Methane exchange was measured in situ with benthic chambers at nine sites distributed in three regions along a salinity gradient from ∼6 in the Baltic Sea (Finland) to ∼20 in Kattegat (Denmark) and ∼26 in Skagerrak (Sweden). The net release of CH4 from seagrass sediments and adjacent unvegetated areas was generally low compared to other coastal habitats in the region (such as mussel banks and wetlands) and to other seagrass areas worldwide. The lowest net release was found in Finland. We found a positive relationship between CH4 net release and sedimentary Corg content in both seagrass meadows and unvegetated areas, whereas no clear relationship between seagrass cover and CH4 net release was observed. Overall, the data suggest that Nordic Zostera marina meadows release average levels of CH4 ranging from 0.3 to 3.0 μg CH4 m–2 h–1, which is at least 12–78 times lower (CO2 equivalents) than their carbon accumulation rates previously estimated from seagrass meadows in the region, thereby not hampering their role as carbon sinks. Thus, the relatively weak CH4 emissions from Nordic Z. marina meadows will not outweigh their importance as carbon sinks under present environmental conditions.

Pengaruh Kadar Air dalam Tanah Terhadap Kadar C-Organik dan Keasaman (pH) Tanah

Pengaruh kadar air terhadap kandungan C-Organik tanah dan keasaman pH tanah dilakukan dengan mengukur kandungan C-Organik tanah menggunakan metode Walkley dan Black sedangkan penentuan keasaman pH tanah dilakukan dengan menggunakan pendekana analisis pH actual (H2O) dan pH pontesial (pH KCl). Kadar air dalam sampel tanah paling tinggi sebesar 20% dengan kadar C-Organik tanah 59,300%, keasamann pH H2O 3,114 dan pH KCl 1,759. Sedangkan kadar air dalam sampel tanah paling rendah sebesar 13% dengan kadar C-Organik tanah 48,640%, keasamann pH H2O 3,359 dan pH KCl 2,062. Kandungan air (kadar air) di dalam tanah mempengaruhi kadar C-Organik tanah dan keasaman pH tanah. Semakin besar kadar air maka semakin tinggi pula kadar C-Organik Tanah dan semakin masam keasaman pH tanah.

Addition of Tithonia Compost and Lime as Ultisol Soil Fertility Improvement for Oil Palm Sedling Media

Research to improve soil fertility, especially the chemical characteristics of Ultisol, has been carried out by adding compost and lime. The incubation method of soil plus compost at a dose of 0.5 kg/pot – 2 kg/pot and 1x exchanged Al lime was carried out for 2 weeks. The results of soil nutrient analysis after incubation were an increase in pH of 0.58 points, a decrease in exchanged Al to unmeasured, an increase in the C-organic content of the soil by 3.44%, an increase in the total N-value of the soil by 0.19%, an increase in the amount of soil organic matter. P-available was 5.81 ppm and exchanged K soil increased by 0.02 me/100 g soil. Likewise, the micro elements analyzed also increase. Thus there is a change in the chemical properties of the soil towards the better. The increase in nutrients N, P, K, Ca, and Mg clearly comes from tithonia, which is the result of decomposition of tithonia compost which is added containing high nutrients. In addition, tithonia compost produces organic acids that can dissolve previously insoluble nutrients into soluble ones. The improvement of the chemical properties of the soil towards a better direction is expected to be able to increase the growth of oil palm seedlings planted on the seedling medium growing.

Kajian C-Organik Gambut Pedalaman pada Berbagai Tutupan Lahan

The study aims to identify the C-organic content of inland peat in various land cover and soil layer depths. This study uses plot sampling methods with the creation of minipits on 4 (four) types of land cover. In each type of land cover, there are 3 (three) plot sampling, so the total plot sampling is 12 fields. Soil sampling is carried out at depths of 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, and 40-50 cm. The research site is in the Special Purpose Forest Area (KHDTK) of Nusa Natural Laboratory and Peat Forest (LAHG) Sebangau. The study was conducted from June to August 2021. Soil samples are analyzed at the UPT Laboratory. LLG-Cimtrop and UPT. Integrated Laboratory, Palangka Raya University. The parameters observed are C-organic, Ash content, Moisture content, Water content, and Fiber content. The data of the study results are analyzed statistically with regression and correlation analysis. The results showed that the land cover that has the highest C-organic content is land revegetation (RePeat) at a depth of 40-50 cm with a C-organic value of 57.81% and the lowest C-organic content in natural forest cover at a depth of 30-40 cm with a C-organic value of 52.2%. The highest ash content is in natural forest cover at a depth of 30-40 cm with an ash content value of 3.18% and the lowest ash content in land cover revegetation (RePeat) at a depth of 40-50 cm with an ash level value of 0.08%. The highest water content is in the revegetation of land cover (RePeat) at a depth of 40-50 cm with a water content value of 318.97% and the lowest water content in the burned land cover at a depth of 0-10 cm with a water content value of 92.56%.

Analysis of Biomass Content of Bottom Plants and Biomass Litter on Agroforestry Land with Slash and Buring System

In this land use, humans act as ecosystem regulators, namely by getting rid of components that he considers useless or by developing features that are expected to support their land use (Mather, 1986; Gandasasmita, 2018), which is a residue and others that can increase soil fertility levels such as soil organic matter, biomass, and necromass. This study aims to measure the biomass content of lower plants and litter biomass on agroforestry land with a slash and burn system. Before and after the combustion process, the ten soil samples showed more C-organic content before the combustion treatment, with a total C-organic of 8.16% - 7.8% = 0.36% C-organic released. The organic matter available before burning is more when compared to after burning, which is 14.05% - 13.43% = 0.62% of the organic matter released. Biomass litter contained wet weight 2500g – 3910g dry weight = -1410 grams of carbon emitted.

Penyuluhan Kesuburan Tanah, Pupuk Organik serta Hama dan Penyakit Tanaman bagi Kelompok Tani Baranuri

<p><em><strong>Counseling of Soil Fertility, Organic Fertilizers, Pests and Plant Diseases for Baranuri Farmers Group</strong>. </em>The Baranuri Farmers Group (KT. Baranuri) is one of the providers of vegetables for the people of Ende City. The results of interviews with farmers obtained several problems, namely, there is no data on soil fertility and lack of understanding of soil fertility, organic fertilizers, pests and plant diseases. The solution given is to analyze soil pH and organic-C to be used as a reference for soil fertility conditions as well as counseling about soil fertility, organic fertilizers, pests and plant diseases. This service activity aims to provide information on soil fertility, increase farmers' knowledge regarding soil fertility, organic fertilizers and plant pests and diseases. The counseling method used is a group approach. Purposive soil sampling, samples were taken diagonally. The organic-C content was analyzed in the laboratory by Walkley and Black method, while soil pH was measured directly on the field using 4 in 1 Soil Survey Instrument and then matching with the criteria of assessment of soil analysis results by the Indonesian Soil Research Institute. The results obtained were the soil pH was 4-5 (very acidic-acidic) and soil organic C was 2.03-2.37% (moderate). The extension activities were succeeded in increasing public knowledge from 46.7% to 86.7% (an increase of 85.7%). The recommendation from this activity is to create a demonstration field to apply an organic fertilizer that can be observed directly by farmer groups.</p>

PENGARUH PUPUK ORGANIK CAIR DARI BONGGOL PISANG TERHADAP KADAR HARA NITROGEN TOTAL DAN C-ORGANIK PADA BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.)

Suspension media is made of natural ingredients to multiply microorganisms that can accelerate the destruction of organic matter. Banana hump contains water, iron, phosphorus, calcium, carbohydrates, calories and protein, which are potential as organic fertilizers. Application of banana weevil fertilizer is expected to increase the carrying capacity of the soil for the availability of organic matter and nutrients. The purpose of this study was to determine the best concentration or dose of organic liquid fertilizer for banana weevil on the vegetative growth of oil palm (Elaeis guineensis Jacq.) seedlings in the Main Nursery. Based on this statement, this research was compiled with the object of oil palm in the Main Nursery. This research was conducted in the Nursery Practice Garden area at STIP-AP Medan. Soil analysis was carried out at the Soil Laboratory of the Agricultural Technology Research Institute (BPTP) of North Sumatra. The time of the study was carried out for 8 months, from January 2021 - August 2021. This study used a Randomized Block Design (RAK) with 2 factors, namely Factor (1) Liquid Organic Fertilizer Banana Cobs and Factor (2) Compound Fertilizer (NPK) 16:16 :16. The treatment was repeated 3 times, with the number of samples being 2 plants so that the sample population was 54 plants. Parameters observed were seedling height, stem circumference, number of leaves, leaf width, root wet weight, shoot wet weight, shoot dry weight, root dry weight, total nitrogen nutrient content and C-organic nutrient content. The data obtained were analyzed statistically by analysis of variance (ANOVA) with 5% and 1% significant difference tests. The results showed that the treatment of banana weevil liquid organic fertilizer and compound fertilizer had no significant effect on the observed parameters. However, the biomass formed was significantly affected as indicated by the weight parameter. The availability of total nitrogen and C-organic nutrients in Ultisol soil showed a very low classification with total nitrogen values of 0.07 – 0.09% and C-organic values of 0.22 – 0.54%.

Kandungan C-Organik Substrat Ekosistem Mangrove di Danau Air Asin Gili Meno Kabupaten Lombok Utara

Gili Meno Lake is one of the salt water lakes located in North Lombok Regency, West Nusa Tenggara Province. Gili Meno saltwater lake has an area of 6.6 hectares with a diversity of biota (flora and fauna) and unique physical and chemical characteristics of the lake waters. The purpose of this study was to determine the total c-organic content of the mangrove ecosystem and the c-organic content contained in the bottom substrate of mangrove stands. This type of research is descriptive quantitative with purposive random sampling method, which starts with sampling the substrate found under mangrove stands and testing in the laboratory using the Walkley & Black method to obtain carbon content. Based on the results of the study found 5 (five) types of mangroves, namely: 1) Avecennia marina; 2) Bruguera cylindrica; 3) Rhizophora apiculata; 4) Lumnitzera racemosa; and 5) Excoecaria agallocha, with the most dominant species being Avecennia marina. The largest % content of substrate carbon was found in the mangrove species Rhizophora apiculata with a total content of 19.995 %C or equivalent to 307.96 tons C/ha. Meanwhile, the potential for the estimated total carbon content of the substrate in the saltwater lake mangrove ecosystem of Gili Meno is 154.2 ± 99.78 tons C/ha or equivalent to 1020.50 tons C in a total of 6.6 hectares of mangrove ecosystem area of the saltwater lake Gili Meno.

Features of the Hydrocarbon Distribution in the Bottom Sediments of the Norwegian and Barents Seas

The results of the study of hydrocarbons (HCs): aliphatic (AHCs) and polycyclic aromatic hydrocarbons (PAHs) in bottom sediments (2019 and 2020, cruises 75 and 80 of the R/V Akademik Mstislav Keldysh) in the Norwegian-Barents Sea basin: Mohns Ridge, shelf Svalbard archipelago, Sturfiord, Medvezhinsky trench, central part of the Barents Sea, Novaya Zemlya shelf, Franz Victoria trough are presented. It has been established that the organo-geochemical background of the Holocene sediments was formed due to the flow of sedimentary material in the coastal regions of the Barents Sea on shipping routes. The anthropogenic input of HCs into bottom sediments leads to an increase in their content in the composition of Corg (in the sandy sediments of the Kaninsky Bank at an AHC concentration up to 64 μg/g, when its proportion in the composition of Corg reaches 11.7%). The endogenous influence on the of the Svalbard archipelago shelf in Sturfiord and in the Medvezhinsky Trench determines the specificity of local anomalies in the content and composition of HCs. This is reflected in the absence of a correlation between HCs and the grain size composition of sediments and Corg content, as well as a change in hydrocarbon molecular markers. At the same time, the sedimentary section is enriched in light alkanes and naphthalene’s that may be due to emission during point discharge of gas fluid from sedimentary rocks of the lower stratigraphic horizons and/or sipping migration.

Estimation of soil carbon storage under mono-specific Enhalus acoroides meadows in Pari Island, Indonesia

Large seagrass meadows in Indonesia are predicted to have a significant ability in capturing and storing carbon and are useful to mitigate global climate change. However, most of the available data are derived from short-term carbon storage of living biomass, whereas data on long-term carbon storage in the soil is still limited. This study, therefore, aims to measure soil carbon storage in mono-specific Enhalus acoroides meadows in Pari Island. A total of nine soil cores was collected in a 100×100 m2 area. The parameters were soil depth, dry bulk density (DBD), and Corg content. We applied a PVC corer with 7.4 cm in diameter and 80 cm in length to collect the soil. The length of the soil core varied between 8 and 67 cm. The mean (±SE) of soil dry bulk density is 0.98±0.04 gr/cm3 and the median is 1.1 gr/cm3, while Corg content is 2.1±0.1% soil DW (mean±SE) and 1.9% (median). E. acoroides vegetation in Pari Island stores around 63 Mg Corg/ha organic carbon in 8-67cm or 34cm (mean depth) of topsoil. Carbon storage of these mono-specific meadows is comparable to soil carbon storage in the seagrass ecosystems per hectare areas on national, regional, and global levels.

RESPON PERTUMBUHAN DAN HASIL TANAMAN KAILAN TERHADAP PEMBERIAN KAPUR DOLOMIT DAN PUPUK BOKASHI KOTORAN SAPI DI TANAH GAMBUT

The study aimed to determine the response of growth and yield of kailan on the interaction effect of a dolomite lime with bokashi of cow manure and its single factor effect. The experiment was conducted in Completely Randomized Design (CRD) with two factors in three replications. The first factor was dolomite lime which consists of 2 t ha-1 (k1), 5 t ha-1 (k2), 10 t ha-1 (k3) and 15 t ha-1 (k4), while the second factor was bokashi of cow manure consisting of 0 t ha-1 (b0), 10 t ha-1 (b1), 15 t ha-1 (b2), and 20 t ha-1 (b3). By observing growth components consisting of relatif growth rate (RGR), crop growth rate (CGR), net assimilation rate (NAR), shoot/root ratio (S/R), and crop yield. As well as the components of soil nutrient content of N, P, K, C-organic content, pH and cation exchange capacity (CEC). The results showed that the application of dolomite lime at a dose of 15 t ha-1 with bokashi fertilizer at a dose of 20 t ha-1 give the highest value of crop growth rate (CGR), net assimilation rate (NAR), shoot/root ratio (S/R), C-organic content, phosphorus (P), and Potassium in peat soil. The application of bokashi fertilizer at a dose of 15 t ha-1 was not different with 20 t ha-1 in terms of relatif growth rate (RGR), crop yield and cation exchange capacity (CEC), and respectively higher than the dose of 10 t ha-1 and without bokashi fertilizer. The application of dolomite lime at a dose of 10 t ha-1 was not different with 15 t ha-1 on the relative growth rate (RGR), and pH of peat soil, and each dose was higher than the doses of 5 t ha-1 and 2 t ha-1 . In terms of nitrogen (N) content, the application of dolomite lime at a dose of 5 t ha-1 was not different with the dose of 10 t ha-1 , and 15 t ha-1 , the N content was higher than the dose of 2 t ha-1 . The increase in the dose of dolomite lime at 20 t ha-1 of bokashi fertilizer showed a positive linier correlation, except for the Potassium which showed a quadratic correlation. The increase dose of dolomite lime in the bokashi fertilizer, the plant growth rate (PAR), net assimilation rate (NAR), shoot/root ratio (S/R), C-organic content, and phosphorus (P) would increase as well. Each single factor of the dose of dolomite lime and bokashi fertilizer showed a positive linier relationship to the relatif growth rate (RGR), crop yield, N-total, pH, and cation exchange capacity (CEC) of peat soil, except for N-total and pH in bokashi fertilizer.

Soil Aggregate-Associated Carbon Fraction Dynamics during the Process of Tea (Camellia sinensis L.) Planting in Southern Guangxi, China

Revealing the variation in soil aggregate-associated organic carbon (Corg) in tea plantations of various planting ages is crucial to shed more light on the accumulation and decomposition of soil Corg in the tea-planting period. This study measured the concentrations of soil Corg, active carbon (Cact), and recalcitrant carbon (Crec) in different-sized aggregates obtained from tea plantations of various planting ages (8, 17, 25, and 43 years old) at the soil depths of 0–20 and 20–40 cm in southern Guangxi, China. According to the wet-sieving approach, soil aggregates were classified as macro- (>0.25 mm) and micro- (<0.25 mm) aggregates, and the former were further divided into coarse (>2 mm), medium (2–1 mm), and fine (1–0.25 mm) fractions. Based on the mean weight diameter (MWD), the stability of soil aggregates was the highest in the 17-year-old tea plantations, and it was closely related to the concentration of soil Cact (0–20 cm: R2 = 0.9744, p < 0.05; 20–40 cm: R2 = 0.8951, p < 0.05), but not Corg (0–20 cm: R2 = 0.1532, p > 0.05; 20–40 cm: R2 = 0.4538, p > 0.05), during the tea-planting process. In the 0–20 and 20–40 cm soil layers, the coarse and medium macro-aggregates had higher concentrations of Corg, Cact, and Crec, regardless of the tea-planting age; meanwhile, the soil Cact/Crec ratio, indicating the Corg availability, increased as aggregate size increased, implying that the soil Corg was younger and more labile in coarse macro-aggregates relative to finer aggregates. Moreover, the tea-planting age significantly affected the Corg, Cact, and Crec reserves in both soil layers. To be specific, continuous tea planting facilitated the accumulation of soil Corg and Crec, but their reserves’ increase rates decreased over time; meanwhile, the soil Cact reserve increased during the early (from 8 to 17 years) tea-planting stage and later decreased. Therefore, during the middle (from 17 to 25 years) and late (from 25 to 43 years) tea-planting stages, maintaining the soil as an Cact pool plays a vital role in facilitating the formation and stabilization of soil aggregates in southern Guangxi, China.

Agarwood Tree Characteristics based on Different Growing Habitat and Ecophysiological Attributes in the Papuan Tropical Forests

Understanding tropical forest characteristics, including forest derivative products such as agarwood, is pivotal. This study focused on perceiving an ideal habitat of the lowland tropical forest ecosystem of West Papua for agarwood-producing tree species. In further, this study identified a close association of biotic and abiotic characteristics to underpin agarwood-producing tree growth. Six sites in three different locations were established to ascertain forest composition and the associated insects. Soil samples were collected to analyze their physical and chemical properties using the Kjeldahl, the Walky and Black, and Atomic Absorption Spectrophotometry (AAS). In addition, temperature, relative humidity, and light intensity were measured. The results noticed two agarwood producing species, Gyrinops caudate and Aquilaria sp., found at an altitude of 400–402 masl in Manokwari, 200–300 masl in Teluk Wondama, and 167.7 masl in Teluk Bintuni. There were no significant differences in temperature, relative humidity, and light intensity. The soil cation exchange capacity was moderate in Manokwari, but it was low in Teluk Wondama and Teluk Bintuni. Total C-organic content in three research sites was classified as high. However, total N content in the three research sites was in the moderate category. The ideal habitat for agarwood in the West Papua forest is from the lowlands to the highlands. Environmental conditions that support the growth of agarwood are moderate temperature, high humidity, and moderate light intensity. Soil fertility also affected the natural growth of agarwood trees. Keywords: abiotic, agarwood association, lowland tropical forest, soil characteristics