Gunawan Djajakirana

• Doctor of Philosophy
• Head of Department at IPB University

Electrogenic microbes have been exploited in the microbial fuel cell (MFC) system for harvesting bioelectricity. Electrogens are widely distributed in various environments, but the exploration of this microbial group from ecosystems in Indonesia is still limited. This present study aimed to isolate the electrogenic bacteria from sediments of two wa...

Sutio G, Iskandar, Indriyati LT, Djajakirana G. 2023. Effectiveness of potassium humate and endophytic bacteria from Serratia marcescens strain NPKC3_2_21 in increasing root weight of paddy cultivation in acidic soil. Biodiversitas 24: 6316-6322. Phosphorus (P) deficiency is a significant factor limiting rice agricultural production in acidic soil....

In agricultural activities, fertilization is important. However, in some cases, plants can grow well without continuous fertilization. This due to the influence of plant litter and the presence of undergrowth which is a source of organic matter that supplies nutrients to the soil. The objectives of this study were to know the dynamic of nutrient re...

Electrogen is a microbial group that plays an important role as anodic biocatalyst of microbial fuel cells (MFCs), one of the most extensively studied microbial-based technologies for bioelectricity generation. The aims of this research were to isolate potential electrogenic bacteria from aquaculture pond sediments and conduct a thorough evaluation...

Microbial fuel cell (MFC), a bio-electrochemical device that exploits electroactive microbes, has gained more attention in developing countries, such as Indonesia. Unfortunately, studies related to bio-electrochemistry are often constrained due to the need for precise and high-cost instrumentation, such as data logger/acquisition or data logging-mu...

Microbial fuel cells (MFCs) are bioelectrochemical instruments that exploit living microbes as biocatalysts for the conversion of chemical energy stored in the bonds of substrates into electrical energy. Monitoring of current or voltage generation in microbial fuel cells at rigid time intervals is noteworthy. Unfortunately, bioelectrochemical studi...

p>Nitrous oxide (N₂O) emissions from agricultural activities contribute significantly to global warming. Understanding the factors influencing N₂O emissions is crucial for developing effective mitigation strategies. This review assesses N₂O emissions from various crops cultivated in tropical mineral and peatland soi...

Pest management is a crucial concern, especially when dealing with insect pests that can cause extensive damage to agricultural crops and the economy. One such pest is the rice stem borer (Scirpophaga innotata), which infests rice stems and poses a significant threat. To combat these pests, various microbial agents have been developed for effective...

The application of microbial fuel cells is still facing some challenges due to its low power output and high internal resistance. It is desirable to obtain a stable and consistent power output from an MFC to support practical real-world applications. Five electroactive bacteria (isolate LGf1, LGf11, LGf15, LGf20, and LGf22) isolated from the sedime...

The price of the AB mix is relatively high, so it needed to find another alternative with a more economical price. One of the alternatives is Liquid Organic Fertilizer (LOF). This study aimed to know the quality of LOF made from banana peels and chicken egg shells, the effect of LOF on the water spinach grown in the hydroponic wick system, and the...

Gambut tropik dengan bobot isi yang rendah berdampak pada berkurangnya kemampuan tanah gambut dalam menopang tanaman. Untuk meningkatkan bobot isi gambut maka dilakukan pencampuran tanah mineral dengan tanah gambut. Namun sumber tanah mineral yang dekat ke lahan gambut adalah tanah berbahan induk ultrabasa dengan kandungan logam Nikel (Ni) yang tin...

ABSTRAK Produktivitas bawang merah sangat bergantung pada kondisi lingkungan dengan tingkat kesuburan tanah yang baik. Kompos merupakan material organik yang penting dalam meningkatkan kesehatan dan kesuburan tanah. Penelitian ini bertujuan untuk mengetahui efek pemberian beberapa jenis kompos yang diproses dengan berbagai bioaktivator berbeda pada...

Berbagai jenis fauna dan flora yang berukuran makro, meso, maupun mikro hidup dan berkembang di dalam tanah. Keberadaan organisme tanah tersebut tidak selalu menguntungkan bagi pertumbuhan tanaman. Fusarium oxysporum merupakan salah satu cendawan merugikan yang hidup dan berkembang di dalam tanah yang dapat menyerang tanaman cabai. Hal ini menjadi...

Biochar merupakan bahan alternatif pembenah tanah dari pemanfaatan limbah biomassa berpotensi sebagai bagian dari upaya rehabilitasi lahan terdegradasi, khususnya lahan kering. Biochar juga berfungsi sebagai habitat mikrob tanah yang berperan penting dalam ketersediaan unsur hara bagi tanaman. Pemanfaatan pupuk hayati di bidang pertanian merupakan...

Sandy soil has a low: ability of water retention, aggregate stability, and nutrient content. To improve its quality a mixture of compost and fly ash-bottom ash (FABA) need to be added to this soil. This study was aimed to determine the effect of compost and FABA as an ameliorant on the chemical properties of sandy soil and plant growth of tomato (S...

Tanah berpasir memiliki kemampuan retensi air, kemantapan agregat, dan kadar unsur hara yang tergolong rendah. Untuk meningkatkan kualitas tanah berpasir ini dilakukan upaya pemberian berbagai dosis campuran kompos dan FABA sebagai amelioran. Tujuan penelitian ini yaitu menguji pengaruh pemberian kompos dan FABA sebagai bahan amelioran pada tanah b...

The effectiveness of rock phosphates (RP) on plant growth is often lower than that of chemically synthesized fertilizer SP-36. Phosphate solubilizing microbes (PSM) are potentially used to enhance RP dissolution and agronomic effectiveness for cacao plant. This study was carried out to assess the ability of several PSM to dissolve insoluble phospha...

This study aimed to obtain the candidate isolates of superior decomposer from several plant block areas in the Bogor Botanic Gardens (KRB). Those candidates were expected to be able to utilize in the fermentation process of solid organic waste. The superior decomposer fungi candidates were selected based on their abilities to produce extracellular...

Cordycep militaris (L) is known in oil palm plantations as a natural enemy of nettle caterpillars. This fungus infects the caterpillars that descend down to become pupae around the palm circle, so that the pupae do not develop into imago and the pest's life cycle will be interrupted. This fungus is one of the 3 main entomopathogenic fungi used as b...

Quantification of CO2 flux from peat has been studied with various methods of measurement and data analysis. Several studies have applied regression analysis to assess carbon flux from tropical peatland as a function of groundwater level. Such an analysis simplified the complex nature of peat decomposition, which involved microbial activities. The...

One of the constraints for crop cultivation at high-pH soil is the low content of micronutrients, especially Cu and Zn, such as in East Nusa Tenggara (ENT) Province with dry climatic conditions, hilly topography, and parent material of limestone. In such land conditions, the ENT community used widely for the cultivation of maize and sorghum crops....

p>Soil factors such as pH and the presence of polyvalent cations can influence the net production of dissolved organic carbon (DOC). This study aimed to determine the main factors that control net DOC production. The study was conducted at Buatan Village, Siak Indrapura Regency, Riau Province, Indonesia. Soil and water sampling were done every mont...

Nugraha HW, Djajakirana G, Anwar S, Santosa DA. 2020. Producing renewable electric energy through a microbial fuel cell in the rice field. Biodiversitas 21: 4139-4146. Microbial Fuel Cell (MFC) is an alternative technology that converts chemical energy into electrical energy using microbes. This study aimed to apply MFC technology in the rice field...

Government Regulation (GR) of Indonesia No. 4/2001 concerning Environmental Damage and/or Pollution Control related to Forest and/or Land Fire summarizes the general criteria for damage to soil properties, both on mineral and peat soil due to forest and or land fires. This GR focuses more on soils in its function as a planting medium and only lists...

Sampah organik dari industri tahu pada umumnya hanya dibuang ke aliran sungai di sekitarnya dan tidak dimanfaatkan oleh masyarakat. Limbah cair tahu mengandung banyak protein, sehingga dalam proses dekomposisi menghasilkan amonia yang menyebabkan bau. Kurangnya peneliti yang memahami bahwa limbah tahu juga dapat digunakan sebagai substrat dalam Sel...

em>The growth of cacao in acid soils is commonly limited by some problems such as low available P and pH, and high Al saturation. Therefore, research is needed to solve the problem of coffee cultivation in acid soil. This study aimed to determine the effect of ameliorant, phosphate solubilizing microbes (PSM), and phosphate fertilizers (P) on the g...

Forest and land fires in Indonesia have become the main national and global concern for the last decade. This disaster can cause enormous losses in the economic, social and environmental sectors because it occurs almost every year. The cause of these fires was always strongly believed to be of human activities (anthropogenic). A definite descriptio...

Value of particle density of tropical peat materials commonly is considered to be 1.4 g/cm ³ . This value was based on the measurementusing a pycnometer. However, this value would not be correct for tropical peat that has coarse material that could plug the narrow opening of the pycnometer. Hence, the use of pycnometer to measure particle density o...

Indonesia has around 14 million ha of peatlands which constitutes 7.4% of Indonesia’s land area and very potential to be developed to support national development, especially related to economic strengthening and in enhancing employment opportunities. An expand areas of peatlands in Indonesia are already being utilized for forest plantation of Acac...

p>One way to control or slow down the nutrient release rate from fertilizer is by coating technique. Nowadays the use of biodegradable coating materials for slow-release fertilizer (SRF) is preferable because of environmental issues. This research was aimed to make SRF using starches and cellulose as the coating materials and to test the release ra...

The effects of biochar as soil ameliorants depend on their characteristics that are influenced by the variation in biomass origin and pyrolysis process. In this context, the objective of this study was to determine the chemical and physical characteristics of seven biochar derived from different biomass wastes - rice husk, corn cob, empty oil palm...

Young leaves of two wild ferns (Diplazium esculentum and Stenochlaena palutris) are uniquely eaten among local peoples in Kalimantan Island. These edible ferns are regarded as important sources of Fe and other trace elements essential for human body. In order to investigate the effect of soil environments on the metal content, we analyzed eight ele...

The use of infertile acidic soil as a nursery growing medium has several limiting factors for plant growth. Application of ameliorant is an efforts to improve the quality of growing medium both the chemical, physical, and biological properties and increase seedling growth. This study was aimed to investigate the effect of biochar and organic fertil...

em>Using acid soil as a cacao seedling medium limits the seedling growth due to low fertility, thus necessitating soil ameliorant treatment to improve its chemical, physical, and biological quality. This study aimed to investigate the effect of cacao husks as organic fertilizer and biochar on chemical and biological properties of seedling media and...

Collembola is one of the dominant microarthopods in almost all soils types. They have important function in food webs soil ecosystem. This research was done at Cikasungka oil palm plantation for six months (April until September 2014). The aim of the research was to collect the information of diversity abundance and population fluctuations of Colle...

The majority of Carbon studies on peats focus on soil carbon. It is rare to examine the amounts of carbon in peat water. As a wetland, peat water contains lots of Dissolved Organic Carbon (DOC). This study aims to portray contents of DOC in peat water from agriculture, shrubs and secondary forests. The research site is Rasau Jaya peat dome, which v...

Abstrak. Memperkirakan konsentrasi karbon organik terlarut (Dissolved Organic Carbon, DOC) sering dilakukan dengan metode pembakaran temperatur tinggi pada alat Total Organic Carbon (TOC). Metode ini memerlukan biaya yang besar, serta keterbatasan jumlah alat TOC nampaknya menghambat penelitian DOC di Indonesia. Karena itu data DOC dari badan-badan...

When it falls to the ground, in soil, herbicides interact with soil particles and plant roots. Herbicides that fell to the ground could be absorbed by soil particles, absorbed by the plants roots, carried by run-off, or it will be degraded. Herbicide residues in the soil can cause poisoning in major crops and can cause pollution to the nearest wate...

Agroforestry systems may play a critical role in reducing the vulnerability of farmers' livelihood to droughts as tree-based systems provide several mechanisms that can mitigate the impacts from extreme weather events. Here, we use a replicated throughfall reduction experiment to study the drought response of a cacao/Gliricidia stand over a 13-mont...

SUMMARY Indonesia as one of the oil exporting countries, at the present time has to find other energy sources to substitute for petroleum oil, because the fossil fuel reserve in Indonesia is becoming less and less. The success of peat utilization for energy especially by some temperate zone countries such as Finland and some member states of the fo...

Dalam dua dasawarsa terakhir ini telah terjadi peningkatan minat para pakar ilmu tanah dan lingkungan dalam menentukan jumlah total mikroorganisme dalam contoh tanah. Minat tersebut muncul karena para pakar menyadari pentingnya peranan mikroorganisme tanah di dalam berbagai proses biokimia yang te'rjadi di dalam sistem tanah, proses retensi dan pel...

Samples were taken from the F/H-, A1-, and A2-horizon in the outer zone, ring zone and inner zone of a fairy ring formed by Marasmius oreades (Bolt.) Fr. on a garden lawn. The mineral component of the soil was mainly derived from loess. The amounts of soil organic C, total N. microbial biomass C, and ergosterol were reduced by 46 to 54% in the ring...

Ergosterol and microbial biomass C were measured in 26 arable, 16 grassland and 30 forest soils. The ergosterol content ranged from 0.75 to 12.94 g g-1 soil. The geometric mean ergosterol content of grassland and forest soils was around 5.5 g g-1, that of the arable soils 2.14 g g-1. The ergosterol was significantly correlated with biomass C in the...

Reclamation of peatland of Indonesia has been carried out during the last 35 years for rice production through transmigration projects. One of the transmigration areas is located in the Berbak Delta, Jambi Province, Sumatra. In the early years, those lands produced rice grain up to 5 tons/ha. However, because the soils have changed into acid sulfat...

Bentonite is a mining material with montmorillonite clay mineral as main component. This mineral possesses high cations exchange capacity therefore naturally capable to absorb cationic pollutant. To increase the capability of bentonite in absorbing pollutant, especially to absorb non polar organic substances, this material has to be activated. In t...