Ganoderma boninense is a pathogen that can attack palm oil plants. This fungus can cause death, causing a decrease in the number of stands and palm oil production. One alternative to control Ganoderma boninense in palm oil is using the biological agent; ‘Trichoderma harzianum’. This research aimed to examine the inhibition of T. harzianum in various media on different spear leaves accumulations on G. boninense in palm oil plants. The research was arranged in a factorial randomized block design. The first factor was T. harzianum application with different media, the second factor was the accumulation of spear leaves on palm oil trees. The data from the observations were analyzed using the analysis of variance, followed by the DMRT at 5% level. The results of statistical tests showed that the application of T. harzianum in various media had no significant effect on the number of spear leaves at 1.5 months after application (MAA) and G. boninense mycelium at 3 MAA, but had a significant effect on the number of spear leaves at 3 MAA, G. boninense mycelium at 1.5 MAA, T. harzianum mycelium at 1.5 and 3 MAA and also significantly affected the root length at 1.5 and 3 MAA. The accumulation of spear leaves significantly affected at 1.5 and 3 MAA but had no significant effect on the observation of G.boninense mycelium, T. harzianum mycelium and the root lengths at 1.5 and 3 MAA. The interaction between T. harzianum in various media and the accumulation of spear leaves had a significant effect on decreasing the number of spear leaves at 1.5 MAA but had no significant effect on G. boninense mycelium, T. harzianum mycelium and the root lengths at 1.5 and 3 MAA. The application of T. harzianum, which was cultured in various media, was able to reduce the accumulation of spear leaves after 3 months of application. The lowest number of spear leaves was found in T. harzianum application with 25% OPEFB + 75% cow dung compost. The best of T. harzianum media in stimulating palm oil’s root growth was 50% OPEFB + 50% cow dung compost.

Mucuna bracteata and Oil Palm Empty Fruit Bunch (OPEFB) forages are large amount of palm oil plantation wastes, but they have not optimally utilized yet. This study analyzed the compost from forage of M. bracteata combined with OPEFB. The study used a complete non factorial randomized design with different treatment composition of M. bracteata and OPEFB as compost material, that is: 100% OPEFB, 75% OPEFB + 25% M. bracteata, 50% OPEFB + 50% M.bracteata, 25% OPEFB + 75% M. bracteata, and 100% M. bracteata. The results showed the differences of M. bracteata and OPEFB as forage composition were significantly affected the content of N, K, and compost yield but did not significantly affect the content of P and C/N ratio of compost. The average of compost C-organic content is 35.97-39.14%, N is 2.3-4.42%, P is 0.53-0.64%, K is 3.75-6.59%, C/N ratio is 8.9-17.9, and compost yield is 56-69%. The greater the composition of M. bracteata, the higher the N content of the compost, but K content is lower and vice versa. If the composting was using OPEFB and M. bracteata as the materials, it is suggested to use a composition of 75% OPEFB and 25% M. bracteata.

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Palm oil mill effluent (POME) is a by-product of palm oil mills. POME application to the field must comply with the regulations issued by the Minister of Environment. The research objective was to determine the soil biological and chemical properties in the rhizosphere of palm oil plant on the land with and without POME application. The research used factorial randomized block design (RBD) with 2 treatments, the first factor was with and without POME application. The second factor was the sample distance from palm oil trees, namely 0 m, 100 cm, 200 cm, 300 cm and 400 cm. Data were analyzed with the analysis of variance at a 5% level and continued with the DMRT at significantly different treatments. The results showed that the POME application had a significant effect on total microbes, soil respiration and cation exchange capacity. The total microbes, C-organic, soil respiration, cation exchange capacity and alkaline saturation on the POME application land were 34.7 x 10−6 CFU ml-1, 2.16%, 1.4 mg C (CO2), 11.1 cmol kg−1 and 40.75%, while on land without POME applications were 1.63 x 10−6 CFU ml−1, 2.32%, 0.52 mg CO2, 7.59 cmol kg−1, and 70.63%. Soil sampling at a distance of 0, 100 cm, 200 cm, 300 cm and 400 cm from the palm oil tree towards the POME application trench had a significant effect on total microbes and soil respiration. The highest of total microbes and soil respiration at 0 cm from oil palm trees were 34.07 x 10−6 CFU ml−1 and 1,14 mg C (CO2). The interaction between soil sampling from the application land and without the application land with the sampling distance treatment from palm oil trees had a significant effect on the soil total microbes parameters. The conclusions of this research were; the application of POME with BOD 180 mgL-1 and COD 593 mgL-1 on palm oil plantations can increase the total soil microbes, soil respiration and cation exchange capacity but did not increase C-organic and alkaline saturation. The closer the application to the palm oil plant rhizosphere, the higher the distribution and microbial activity.

Oil palm empty fruit bunches as a by-product of palm oil fresh fruit bunches processing are generally applied in oil palm plantation areas. This research aim was to determine the effect of oil palm empty fruit bunches application on total microbes and soil respiration. This research used a factorial randomized block design. Factor I is the sampling area, consisting of areas without application and area with the application of oil palm empty fruit bunches (OPEFB). Factor II is the depth of soil sampling, consisting of a depth of 0-10 cm, depth of 10-20 cm, depth of 20-30 cm and depth of 30-40 cm. The total microbes in the area with OPEFB application were 33.373 × 106 CFU ml−1 with soil respiration of 2.257 mg CO2 day−1. On land without OPEFB application, total microbes were 16.64 × 106 CFU ml−1 with soil respiration of 12.20 mg CO2 day−1. On differences in the depth of soil sampling, the highest total microbes were found at a depth of 10-20 cm i.e. 33.998 × 106 with soil respiration of 19.14 mg CO2 day−1. The application of oil palm empty fruit bunches had a positive contribution to increase total microbes and respiration in the soil.