TY - JOUR AU - Lestari, Indarti Puji AU - Susila, Anas D. AU - Sutandi, Atang AU - Nursyamsi, Dedi PY - 2020/04/30 Y2 - 2024/03/29 TI - Studi Korelasi K pada Tanah Ultisol untuk Tanaman Bawang Merah (Allium ascalonicum L.) JF - Jurnal Hortikultura Indonesia JA - J Hort Indonesia VL - 11 IS - 1 SE - Articles DO - 10.29244/jhi.11.1.41-50 UR - https://journal.ipb.ac.id/index.php/jhi/article/view/32073 SP - 41-50 AB - Determination of soil nutrient contents requires an appropriate extraction method between the desired soil and plants. The objective of the study was to determine the best soil K extraction method for shallot in Ultisol with a single location approach. The study was carried out in Lebak, Banten Province during March 2015 until May 2016, with two stages, namely manufacture soil K nutrient status and K correlation test through planting in a greenhouse. The manufacture of soil K nutrient status consisted of very low to very high (0X, 1/4X, 1/2X, 3/4X, and X), the value of X represents the highest value of K nutrient absoprtion, equal to 509.6 kg K2O ha-1. On this stage, K fertilizer was incubated for three months, followed by taking soil samples in each plot to analyze the soil K contents. The soil K content was analyzed by using five types of extraction methods, namely Bray I (solution 0.025 N HCl + NH4F 0.03 N), Bray II (NH4F 0.03 N + HCl 0.10 N), Mechlich I (0.0125 M H2SO4 + 0.05 M HCl), HCl 25% and Olsen (NaHCO3 0.5 M, pH 8.5). The K correlation test was carried out in a greenhouse by using a Completely Randomized Design (RAL) with five replications. The results showed that manufacture soil K nutrient status increased K levels in the soil with the indicators of canopy dry weight which giving a quadratic response pattern. The best soil K nutrient extraction method for shallot on the Ultisol soil is Mechlich I, with correlation coefficient value of 0.77. The results of this study can be used for the determination of K fertilization recommendation on shallot in Ultisol soil.Keywords: K nutrient status, K extractant, K fertilization dose ER -