Utilization of nyamplung industrial waste for compost and the response to nyamplung seedlings growth and nitrogen uptake

The solid waste (dregs seed) of nyamplung ( Calophyllum inophyllum ) industry from seed pressing processes could be more than 50% of the dry seed weight. Nyamplung oil industry in Bantul (Yogyakarta) has been produced nyamplung oil 4-5 ton/month that produced dregs seed around 50-60%/ton nyamplung dry seeds. The accumulated waste has been piled up and immediately important to utilize it. This study aimed to determine (i) the effect of bioactivators with ameliorant material application and the interactions among treatments on nyamplung dregs compost quality, and (ii) the growth response, seedling quality index and nitrogen uptake on nyamplung seedlings with nyamplung dregs compost application. The study was arranged in Completely Randomized Design (CRD) factorial. Two bioactivators Prouponic Gb#1 and cattle rumen bio starter were used in the study. The bioactivators were combined by ameliorants (no ameliorant, dolomite, and rice husk ash) with 3 replicates for each treatment. Analyses of soil chemical properties were carried out on nyamplung dregs before and after the treatments applied including: pH, DHL, N Total, C/N ratio, P Total, K Total. Those characters were compared to SNI No.19-7030-2004 on compost quality standards. DHL, C/N ratio, the total N, P, and K met the criteria on SNI. Seedling growth characters (height, diameter, number of leaves) and seedling quality index varied between nyamplung dregs compost treatments and control up to 16 weeks observation. Nyamplung dregs compost application showed the highest N uptake on nyamplung seedlings compared to the controls. Nyamplung seedling quality index was highly influenced by the uptake of N nutrients in the shoots and the roots than by height character and diameter.