Biochar and Biochar-Compost Effects on Soil Quality and Maize (Zea mays L.) Performance in Mubi, Northern Guinea Savannah of Nigeria

Abstract

An experiment was conducted at the research farm of the Federal Polytechnic, Mubi, in 2025 cropping season to analyzed the effect of biochar, and biochar-compost on maize performance and soil quality in Mubi. Mubi lies between latitude  10’8’ N and N10’30`N of the equator and longitude 13’10’E and 13’25`E at an altitude of 696 m above sea level located in the Northern Guinea Savanna zone of Nigeria with mean annual rainfall of 1000 mm with peak from July to September. There have been many studies on soil quality and crop yield using different biochar application amounts, but few studies have focused on the combination of different amounts of biochar application mixed with compost in moderately degraded soils. In this study, the methods of mixing biochar alone evenly with the soil (B) and mixing compost (BC)) were used to reveal how biochar, biochar-compost application methods influenced soil quality, crop yield and agronomic characteristics in moderately degraded soil (soil organic matter (SOM), 30.33 g kg⁻¹). The biochar and compost application amounts were 0 (control), 10 (level 1), 15 (level 2), and 20 (level 3) t ha⁻¹ in both the B and BC treatments. The results showed that, compared with control, BC3, B2 and B3 increased maize yield but not significantly. BC1 and B1 had the lowest maize yield. BC2 tended to delay maize leaf senescence. There was a positive linear relationship between soil quality index (SQI) and biochar application amount in BCO. Compared with other treatments, the pH, EC, SOM, available phosphorus, sucrase and catalase activities were highest in BC3. However, the effects of B on soil quality and crop productivity were limited at first but gradually increased with time. Overall, BC3 was beneficial for improving the soil quality and crop productivity in Mubi soils for short-term cultivation.