A clinoptilolite-zeolite sample was obtained from Bayah natural deposit, Banten, whereas the EFBOPB was prepared by employing a slow-pyrolysis process with 300˚C - 400˚C temperature for about eight hours [17] [18]. Three samples of zeolite analyzed consisted of three different particle sizes, i.e., 60 - 80, 80 - 100, and 100 - 150 mesh. The physical characterization included pore structure, pore space area, water and gas (CO₂ and N₂) adsorption capacity by using Brunaer-Emmet-Teller method [19] [20]. In contrast, the chemical properties were determined by using standard laboratory analyses outlined by SNI 13-3494-1994 (ICS 73.080), including pH (in water by pH-meter), organic C (spectrophotometry), Nitrogen (N) (Kjeldahl), Phosphate (P₂O₅) (spectrophotometry), potassium (K₂O) (integrated couple plasma, ICP), cation exchange capacity (titration), selected heavy metals and micro-nutrients (ICP), and bacterial contaminant E. coli and Salmonella (total plate counts). Both physical and chemical analyses were performed at Indonesian Research Institute for Biotechnology and Bioindustry, Bogor, Indonesia.

Mineralogical composition of the best zeolite powder was determined by using x-ray diffraction (XRD) analysis by running at 0˚ - 30˚ 2- θ with Cu Kα at the Chemical Laboratory of the Indonesian Institute of Sciences (IIS) at Serpong, Banten. Identification of the mineral present was carried out by using major intensive peak characterizing the mineral according to [21]. To obtain particle surface appearances a scanning electron microscopy analysis was performed at the same laboratory. Both materials samples were examined with a Scanning Electron Microscope (SEM). The electron beam is accelerated through a high voltage 20 kV and pass through a system of apertures and electromagnetic lenses to produce a thin beam of electrons [22]. In the early stages a material sample leveled with a special tool. After sputter coating the cast with 35 nm of gold-palladium (Au-Pd), electron micrographs were generated using a Jeol JSM-5310LV SEM.

Adsorption capacity analyses of the Bayah zeolite and EFBOPB were performed by using CO₂ and N₂ adsorption analyses at Chemical Laboratory, IIS, Serpong, Banten, employing gas adsorption/desorption isotherm described as follow. Sample was pretreated by heating at 350˚C for 90 minutes under Helium (He) gas (inert) exposure. Adsorption of CO₂ under 5% (v/v) He was carried out at ambient temperature for 30 minutes followed by purging with Helium gas (inert) for 30 minutes at the same temperature. Desorption of CO₂ was conducted at 100˚C - 700˚C temperature with 10˚C·minute⁻¹ increment, hold at 700˚C for 10 minutes. Gas flow rate was maintained at 30 cm³·minute⁻¹. Similar protocol was also applied for N₂ adsorption measurement with gas flow rate of 40 cm³·minute⁻¹. Two MPMs combination were formulated, i.e., 75% zeolite 100 - 150 mesh + 25% EFBOPB and 50% zeolite 100 - 150 mesh + 50% EFBOPB (w/w), and subjected to gas and water adsorption analyses. As EFBOPB adsorb others gases on top of CO₂, then the adsorption measurements of formulated MPMs were carried out in two conditions, with and without CO₂ adsorption.

The zeolite used in this experiment was originated from Bayah, Banten, calcinated at 150˚C for four hours, and pyrolyzed EFBOP (EFBOP biochar or EFBOPB). Two formulations were made by using zeolite/biochar ratios of 50:50 and 75:25 (% w/w). These formulas then inoculated by Bulkholderia cenocepacia, a superior exopolysaccharide-producing bacterium from IRIBB isolate collection which is capable of promoting a stable aggregation of peat soil using Bayah zeolite as carrier [23]. Fresh bacterial culture was prepared by growing the isolate on a 250 mL ATCC liquid medium consisting of (L⁻¹): 0.2 g KH₂PO₄; 0.8 g K₂HPO₄; 0.2 g MgSO₄·7H₂O; 0.1 g CaSO₄·2H₂O; 2.0 mg FeCl₃; Na₂MoO₄·2H₂O (trace); 0.5 g yeast extract; 20 g sucrose; and final pH 7.2 and incubated for 48 - 72 hours at 30˚C. The innoculant was then inoculated into the MPM formulas at 5% (v/w) concentration.

A simulation laboratorial study was carried out to determine the potential function of formulated MPMs in reducing the peat from fire hazard. The experiment used in-land peat from Ciamis, West Java, with decomposition level and bulk density of 0.3 - 0.4 g·cm⁻³, employing a method described by [24]. A special apparatus used was based on the design of IRIBB and Labodia. Parameters observed on peat treated with formulated MPM include speed and patter of fire creeps, water content, and bulk density. The burning test containment used is shown in Figure 1. It was made of stainless steel with 50 × 50 × 50 cm³ size, with inner divider of calcium silicate board and a burner was mounted in the left side with 400 mm length. Temperatures were measured by using thermocouple type K at nine different points i.e., three in each depth of 125, 250, and 375 mm at a distance of 75, 250, and 425 mm. The thermocouple has 15 mm diameter with 500 mm probe length and accuracy of two degrees centigrade. Air flow to induce burning was facilitated by holes with 3.25 cm in diameter in other side of the container representing 1.8% openness of total area of the container. This property

was designed in a specific size in order to provide airflow and to help maintain the perfect burning process. All treatments were recorded by using a Midi Logger GL240 to set electric power, temperature, and burning period. Burning media for this experiment were simulated by using the mixture of rice straw and coarse peat (1:3 and 3:1 w/w) with maximum water content of 15% and bulk density 0.4 - 0.5 g·cm⁻³. The addition of MPM material into the burning medium was zeolite or EFBOPB at 0%; 1%; 1.5%; 2%; and 2.5% (w/w) rate and water content of 10.4% (zeolite) and 5.7% (EFBOPB).

As shown in Table 1, both MPM materials studied have alkaline reaction in which the average pH values of zeolite (7.7) were lower than those of EFBOPB (9.5). In contrast, the contents of N and K were found higher in the former, whereas the opposite was true on the P content and CEC value. Based on the Indonesian Industrial Standard (SNI) for CEC value, the 100 - 150 mesh zeolite (126.45 cmol⁽⁺⁾·kg⁻¹) met the standard of SNI 13-7168-2006 (min 100 cmol⁽⁺⁾·kg⁻¹), whereas that of EFBOPB was far below of zeolite. However, as the MPMs formula at the end should met the minimum requirement of an inorganic soil ameliorant formula set by the Ministry of Agriculture, then it should be oriented to meet this standard as indicated in Table 1. According to this ministerial decree the contents of heavy metals and microbial contaminants in the MPM materials, except for CEC value of EFBOPB, passed the standard values. Based on this evidence, the formulation of MPMs consisting a mixture of 100 - 150 mesh zeolite and EFBOPB at 75:25 and 50:50 (% w/w) composition was made and tested further. This study found that increasing the surface area of the zeolite to 100 - 150 mesh improves the physical and chemical reactions on the zeolite, resulting in a higher CEC value and release of P, K, and micronutrients (Fe, Mn, and Zn) than 60 - 80 or 80 - 100 mesh.

^*)Indonesian Agriculture Ministerial Decree, ^**)Nd (Not detected).

Based on X-ray diffractograms (XRDs) shown in Figure 2, it is indicative that the Bayah natural zeolite was dominated by a clinoptilolite with poly-cations K-Mg [K5.17 Mg0.16 (Al6 Si30 O72). 24H₂O]. There were no significant different in the indicative peaks showing the presence of the mineral among the three particles size analyzed i.e., at the 2 θ position corresponding to 9.8, 22.3, and 25.6 Å particle diameters [15]. However, a smaller size particle tends to produce a background noise in the XRDs. On the other hand, the SEM analyses showed that the MPM formula containing 100 - 150 mesh zeolite particles were aggregated after inoculated with B. cenocepacia (Figure 3). It is indicative that EFBOPB has larger pore sizes compared those of zeolites as shown in Table 1. However, the diameter sizes of pores in zeolite tend to be bigger with decreasing particle size of the mineral. As the capacity of adsorption is directly related to the pores volume, then the 100 - 150 mesh particle was chosen as MPM formula component.

Data shown in Table 2 are the values of CO₂ and NH₃ gases each adsorbed by each MPMs studied. Zeolite material can adsorb CO₂ or NH₃ alone without any other gases involved, whereas the EFBOPB adsorbs more other gases (unidentified) than CO₂ or NH₃. Therefore, the measurement of gases adsorption capacity of the EFBOPB was carried out with and without CO₂ or NH₃ adsorption. The net CO₂ or NH₃ adsorption was then obtained by the different of the two measurements. It is indicative that 100 - 150 mesh zeolites adsorb CO₂ and NH₃

more than those by smaller particle sizes, whereas EFBOPB adsorb other gases (2.54 mmol·g⁻¹ CO₂ and 2.76 mmol NH₃) more than CO₂ (0.08 mmol·g⁻¹) or NH₃ (0.05 mmol·g⁻¹) and the total values (2.61 mmol CO₂ g⁻¹ and 2.81 mmol NH₃ g⁻¹) were higher than those of the zeolites (1.06 to 2.40 mmol CO₂ and 0.84 mmol to 1.03 mmol NH₃ g⁻¹). However, addition of zeolite into EFBOPB in formulated MPM improved the capacity of MPM in adsorbing the gases (2.05 and 1.56 mmol CO₂ g⁻¹ and 2.06 and 1.82 mmol NH₃ g⁻¹ for formula 50:50 and 75:25, respectively). The mechanism causing this phenomenon is unclear yet. Theoretically, in 50:50 formula, the proportion of adsorbing capacity supposed to be 1.24 mmol CO₂ g⁻¹ and 0.54 mmol NH₃ g⁻¹. On the other hand, these values become 1.67 mmol CO₂ g⁻¹ and 0.52 mmol NH₃ g⁻¹ in the 75:25 formula. It is assumed that the capacity of gases adsorption is related to the physical characteristics of the MPM i.e., volume in pores and total area pores. A regression analysis presented in Figure 4 shows that both CO₂ and NH₃ adsorption capacities were highly correlated more with volume in pores compared to the total area pores. This evidence was presumably indicating that the adsorption mechanism was more physically in nature rather than electrostatically.

Furthermore, synthetic nitrogen (N) fertilizers, widely used in agricultural and plantation crop fertilization, are a significant source of greenhouse gas emissions. It is commonly assumed that the use of this N fertilizer significantly contributes to the cause of N₂O emissions from the soil. Agricultural and plantation cultivation technology have advanced considerably in recent years and various efforts have been made in to reduce greenhouse gas emissions, including reducing fertilizer dosage and utilizing soil microorganisms to increase fertility and land productivity. According to research [25], an equivalent emission of 1052.26 - 1209.51 kg CO₂-eq ha⁻¹ for each release of N₂O between 19.11 - 22.17 kg N₂O-N ha⁻¹. According to the Intergovernmental Panel on Climate Change [26], one percent of N₂O-N emissions are caused by the total N applied during fertilization. Based on the findings of the preceding study, additional research on the impact of using N fertilizers and practical efforts are required. This study investigated the potential use of zeolite and its combination with EFBOPB as a molecular sieve material for adsorbing N₂ gas. When compared to 80 - 100 mesh (71.7 cm³·g⁻¹ STP) and 60 - 80 mesh (67.7 cm³·g⁻¹ STP), zeolites with particle sizes of 100 - 150 mesh have a higher adsorption capacity (75.6 cm³·g⁻¹ STP) of N₂ (Table 3). This confirms the previous results showing that the smaller the size of zeolite the higher the capacity in gas adsorption.

One of the final objectives of incorporating the MPMs on the peat soils is to reduce the potential risk of the peat from land firing by improving water holding capacity of the organic material particularly those litters lying on the soil surface which acts as the main source of peat burning [27] [28]. Regression analyses indicates that the dosages of MPMs were linearly correlated with the time of fire spread (Figure 5). The more MPMs is added the longer time needed by the fire to spread out. This evidence leads to the assumption that the phenomenon was taken place due to the increase of water contents in the organic media after the MPMs addition. Data shown in Table 4 support this assumption in which all MPMs studied have WHC (39.10% - 60.50% w/w) higher than the original organic media before the MPMs addition (14.4% w/w).

Although, the data have not reached a maximum level for the dosage’s effect, the slope of the equation indicating that the dosage of EFBOPB would be lower than the zeolite and that of the formula MPMs 75:25 would be higher than the 50:50 formula to achieve the same time of fire spread. This evidence shows that the contribution of EFBOPB on slowing down the spread of fire is higher than that of zeolite. However, further field study is necessary to validate the effects of the formulated MPMs on peat degradation protection upon intensive agricultural practices.