Perubahan Sifat Kimia Tanah Ultisol Setelah Panen Padi Gogo (Oryza Sativa L.)…

ABSTRACT The research aim to study the change of ultisol soil chemical properties after crop upland rice (Oryza sativa L.) that applied biochar from agricultural waste as rice husk and shell of coconut. The research was conducted at Agricultural Faculty Experimental Unit and soil laboratory, university of riau, pekanbaru city. The research was conducted experimentally with a completely ra…