@article{Lestari_Susila_Sutandi_Nursyamsi_2020, title={Studi Korelasi K pada Tanah Ultisol untuk Tanaman Bawang Merah (Allium ascalonicum L.)}, volume={11}, url={https://jurnal.ipb.ac.id/index.php/jhi/article/view/32073}, DOI={10.29244/jhi.11.1.41-50}, abstractNote={<p><em>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.</em> <em>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<sup>-1</sup>. On this stage, K fertilizer was incubated for three months, followed by taking soil samples in each plot </em><em>to analyze the soil K contents</em>. <em>The soil K content was analyzed by using five types of extraction methods, namely </em><em>Bray I (solution 0.025 N HCl + NH<sub>4</sub>F 0.03 N), Bray II (NH<sub>4</sub>F 0.03 N + HCl 0.10 N), Mechlich I (0.0125 M H<sub>2</sub>SO<sub>4</sub> + 0.05 M HCl), HCl 25% and Olsen (NaHCO<sub>3</sub> 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.</em></p> <p><em>Keywords: K nutrient status, K extractant, K fertilization dose</em></p&gt;}, number={1}, journal={Jurnal Hortikultura Indonesia}, author={LestariIndarti Puji and SusilaAnas D. and Sutandi, Atang and Nursyamsi, Dedi}, year={2020}, month={Apr.}, pages={41-50} }