PERUBAHAN JERAPAN P PADA ULTISOL AKIBAT PEMBERIAN CAMPURAN ABU TERBANG BATUBARA-KOTORAN AYAM Changes of P Sorption on Ultisol due to Addition of Coal Fly Ash-Chicken Manure Mixture - Hermawan, Agus (Department of Soil Science, Faculty of Agriculture, Sebelas Maret University, 2014)