Korelasi Ekstrak Kalium Tanah Ultisol dan Oksisol dengan Respons Tanaman Jagung

Abstract

Ultisol and Oxisol are two kinds of soil that have widcly distribution in Indonesia, which is potential to the developed in crop agriculture like C0111. Low level of potassium nced fertilized that appropriate with thc plants demand. The selected extraction method to measure the potassium needed were detennined through the correlation test between the concentration of potassium soil and the plants response. This expcriment were conducted in Ultisol and Oxisol soil Balambangan Pagar, Lampung Utara to select the best extraction method of potassium soil for corn. The experiment used five status potassium levels, that is very low (OX), low ('1,X), medium (VoX), high Oc.X), very high (X), which X = 631,68 mg KCllpot or equivalent with 1287,32 kg Kel/ha, that is the potassium demand to reach the very high potassium content. Each POk1ssium levels was fertilized with 0, 40, 80, 160, 320 mg KCllpot. Respectively plants response were correlated with the potassium soil that estimated by five method, HCI 25%, Olsen, Morgan Wolf, Morgan Vanema, and NH4-asetic pH 7,0. The result showed that fertilization of K significantly increased the plants only in very low level ofpotassiulll soil as 19,8% in Ultisol and 28,6% in Oxisol. For the increasing height weight of dry pbnts was 1,87-27,27% in Ultisol and 0,26-18,74% in Oxisol. The capability of each method in determining the potassium in soil could be different. Hel 25%, Olsen, Morgan Wolf, Morgan Vancma, dan NH.l-asclic pH 7,0 method were selected to estimate K fertilizer needed in Ultisol for corn,and in Oxisol soil was Olsen and NH4-asetic pH 7,0 method.