Society of African Journal Editors

Nigerian Journal of Soil and Environmental Research

Nitrogen fertilizer replacement value of legumes with residues incorporated in the guinea savanna zone of Nigeria

Authors: M.K.A Adeboye

Journal: Nigerian Journal of Soil and Environmental Research

Crop rotation with legumes can help reduce the inorganic nitrogen fertilizer need of the following maize as a result of increased nitrogen availability in the soil. The Nitrogen Fertilizer Replacement Value (NFRV) method was used to estimate the nitrogen contribution of grain legumes (soybean, cowpea) and an herbaceous legume (Centrosema pascuorum), to a succeeding maize crop. The legumes and fallow fields were established in 2001 followed by a test crop of maize in 2002 with inorganic fertilizer rate of 0, 20, 40 and 60 kg N ha-1. The soil inorganic nitrogen was significantly (P Key words : Guinea savanna, incorporation, legume residues, N fertilizer replacement value.