1 23 Biochar ISSN 2524-7972 Biochar DOI 10.1007/s42773-020-00059-x Short-term application of biochar increases the amount of fertilizer required to obtain potential yield and reduces marginal agronomic efficiency in high phosphorus- fixing soils Tigist Melaku, Gebermedihin Ambaw, Abebe Nigussie, Amsalu Nebiyu Woldekirstos, Eshetu Bekele & Milkiyas Ahmed