The efficiency of phosphorus uptake by plants in an Ultisol soil is very low because most of the soil phosphorus is precipitated by Al and Fe. Oil palm empty fruit bunches can be used as basic materials of biochar and compost, and as sources of isolates of phosphate solubilizing fungi. This study was aimed at elucidating the effect of application of phosphate-solubilizing fungi with biochar and the compost produced from oil palm empty fruit bunches on the growth and yield of maize an Ultisol of Central Kalimantan. This study consisted of two experiments. The first experiment was inoculation of four isolates of phosphate solubilizing fungi isolated from of oil palm empty fruit bunches, i.e. Acremonium (TB1), Aspergillus (TM7), Hymenella (TM1) and Neosartorya (TM8) to 'biocom' media (mixture of biochar and compost generated from oil palm empty fruit bunches) to obtain phosphate-solubilizing fungi that can adapt to the media. In the second experiment, the best results in the first experiment were applied to an Ultisol soil planted with maize. The results showed that the isolates that were best adapted to biocom media were Aspergillus-TB7 with 60:40 proportion (60% biochar + 40% compost) and Neosartorya-TM8 with 70:30 proportions (60% biochar + 40% compost). The use of the first experiment results in the second experiment showed that the application of biocom plus Neosartorya-TM8 (BTM) on an Ultisol soil significantly improved the growth and yield of maize, as well as its the phosphorus uptake and uptake efficiency .

The availability of P in acid soils may be raised through the application of phosphatesolubilizing fungi (PSF). Coal fly ash (CFA) that has a high pH and contains a relatively high P may also be used to raise the availability of P in acid sois. The purpose of this study was to explore the possible use of CFA and PSF in a biochar-compost carrier to improve the availability of P and plant growth in acid soil. Combined applications of two PSF isolates (Aspergillus oryzae = F1, and Neosartorya fischeri = F2) carried in three levels of biochar-compost (80% biochar + 20% compost = B1, 70% biochar + 30% compost = B2, and 60% biochar + 40% compost =B3), and two doses of CFA (60 t/ha = C1, and 80 t/ha = C2) were tested in this study through two experiments. The results of experiment 1 (laboratory experiment) showed that the application of N. fischeri carried in 70% biochar + 30% compost combined with 80 t CFA/ha (F2B2C2 treatment) significantly increased the available P more than other treatments. In comparison with control, the increase of soil available P content ranged from 13% in the F1B1C1 treatment (A. oryzae in 80% biochar + 20% compost combined with 60 t CFA/ha) to 101% in the F2B2C2 treatment (N.fischeri in 70% biochar + 30% compost combined with 80 t CFA/ha). The results of experiment 2 (glasshouse experiment) showed that the highest dry weight of maize shoot was obtained by the F2B2C2 treatment that increased 123% compared to control. The highest P uptake by maize was obtained by the F2B2C2 treatment (N. fischeri in 70% biochar + 30% compost combined with 80 t CFA/ha).

The increment of peat soil productivity meets through ameliorant addition. Ameliorant sources can be obtained from oil palm plantation and electric steam power station waste. The study aimed at investigating the ability of the oil palm fruit empty bunch (OPFEB) biochar, palm oil boiler ash (POBA) and coal fly ash (CFA) as alternative ameliorants besides compost to improve nutrient availability in peat soil of Central Kalimantan. Treatments tested were OPFEB biochar, POBA, CFA, compost, OPFEB biochar+compost, POBA+compost, and CFA+compost. The seven treatments were arranged in a completely randomized design of single factor with four replications. The results revealed that the ameliorants increased peat soil pH at a rate of 0.7 compared to those in initial soil used and available P of 135.7% even though there was no significant increment of exchangeable cations of K, Ca and Mg. Mixing of biochar, POBA or CFA with compost improved nutrients availability in peat soil.

<p>Cultivating of melon particularly in Central Kalimantan has been widely undertaken by farmers, however, the yields have not been able to meet the melon needs of Central Kalimantan's community. One of the breakthroughs in overcoming the problem is by growing melons on swamp floating beds, namely ambul technology. Ambul is growing media from decomposed floating aquatic plants, constructed with bamboo or wooden as a frame, that is let floating on waters. The ambul based on the consideration that the community lacks access to land for most of the year, which reduces opportunities for growing crops. The research design used was Split Plot Design with three kinds of aquatic plants as the main factor namely <em>Eichornia crassipes, Salvinia molesta, Eleocharis palustris</em>, and two melon varieties as subplot factors specifically Action 434 and Amanta. The results showed that the Amanta variety grown on <em>S. molesta</em> media produced the highest value of crop length on 1, 2, 3 weeks after planting (WAP). <em>S. molesta</em> was the best planting media for enhancing flowering by 11.43 days after planting (DAP) and weight of fruit (3.18 kg per plant. The variety of Amanta also had the highest value of root dry weight of 1.33 g per plant and fruit weight of 2.08 kg per plant.</p>

The peatlands have the potential to support food security efforts. However, there is have constraints on soil fertility, especially the P nutrients availability. The biotechnology approach, the application of ameliorant (biochar-compost carrier medium (biocom)) enriched with phosphate solubilizing fungi (PSF) and coal fly ash (CFA), was expected to increase the P-availability in peat soils. The research aimed to study the application of biocom enriched with PSF and CFA to increase soil P-availability and plant P-uptake. The study was conducted using peat soil media with the formulation of CFA and biocom enriched with PSF and CFA as treatments. The treatment effect was observed through soil P available and plant P uptake of maize. The results showed PSF application was inconsistent in improving P available in peat soils in Kalimantan. In Central Kalimantan, Biocom + PSF was able to increase P available in peat soils by up to 406.18% (A. oryzae-Tb7) and 353.44% (N. fischeri-Tm8). However, in South Kalimantan P available in peat soil was only 8.04% (A. oryzae-Tb7) and 12.86% (N. fischeri-Tm8). The CFA+ (biocom+PSF) formulation increased P available in Central Kalimantan peat soils, but it was different from South Kalimantan peat soils. The application of biocom+PSF and CFA has not been able to increase the P uptake of maize plant in peatlands of South Kalimantan.