ABU JANJANG KELAPA SAWIT SEBAGAI SUBSTITUSI PUPUK KALIUM PADA BAWANG MERAH YANG DIBUDIDAYAKAN DI TANAH GAMBUT

Abstract

The research aims to determine the best dose of oil palm bunch ash as a substitute for
KCl for growth, and yield of shallot plants on peat soil. The research took place from January to
March 2020 located in Bengkulu City. The experimental design used in this research was a
Complete Randomized Block Design with a single factor, a combination of oil palm bunch ash
(OPBA) doses and KCl fertilizer. The treatment combinations were 100% KCl (300 kg KCl/ha),
75% KCl + 25% OPBA (225 kg KCl/ha + 171.10 kg OPBA/ha), 50% KCl + 50% OPBA (150
kg KCl/ ha + 342.20 kg OPBA/ha), 25% KCl + 75% OPBA (75 kg KCl/ha + 513.30 kg
OPBA/ha), and 100% OPBA (689.41 kg OPBA/ha). Each treatment was repeated 4 times. The
collected data was analyzed statistically with Analysis of Variance (ANOVA) using the F test
5% level. Comparisons of mean values between treatments were tested using the Duncan
Multiple Range Test (DMRT) 5% level. The best application combination of OPBA with KCl
in peat soil for shallot plants was 225kg KCl/Ha + 171.10 OPBA/ha (75% KCl + 25% OPBA).
At this dose, the bulb number per clump and dry weight of shallot bulbs reached the best values
compared to the other treatment combinations. Palm oil bunch ash could substitute 25% of
potassium requirements from KCl for cultivated shallot on peat soil.

Key word : oil palm waste, organic fertilizer, peat soil, fertilizer substitution