¹Under Graduate Program of Agrotechnologi, Universitas Sebelas Maret

²Faculty of Agriculture, Universitas Sebelas Maret, Indonesia

Email: t4ufikahmad@gmail.com

The prospect of red ginger development in Indonesia is still good, especially for exports, the traditional medicine industry, food, beverages and cooking spices, where this must be followed by a balanced red ginger productivity so that proper fertilization is needed to yield increase. KCL fertilizer affects the metabolic processes, physiology and plant nutrition. This study aims to determine the effect of giving and obtaining the optimal dose of KCl fertilizer in increasing the growth and yield of red ginger. This research was conducted in March-August 2021 at Pelem, Wonorejo, Jatiyoso, Karanganyar with coordinates 7°43’24.7”S 111°05’31.2”E and the altitude is 800m.asl. The design used was a one-factor Randomized Completely Block Design (RCBD) with 4 levels and repeated 6 times to obtain 24 experimental units. The treatments in this study were as follows: P0: Without KCL fertilizer, P1: Treatment 50kg KCl.ha^-1, P2: Treatment 100kg KCl.ha^-1, P3: Treatment 150kg KCl.ha^-1. The results showed that KCL fertilizer application at a dose of 50kg.ha^-1 tended to increase ginger yields, namely fresh weight per plot with an average of 351.17 grams and rhizome storage weight per plot with an average of 259.17 grams. The application of high doses of KCL fertilizer actually reduced the number of tillers, although it did not change the other growth components.