Optimization of Tillage Practices for Enhanced Sorghum Productivity in Semi-Arid Nigeria

Abstract

Sorghum (Sorghum bicolor (L.) Moench) is a critical cereal for food security in semi-arid regions, yet yields in Nigeria remain suboptimal due to inadequate agronomic practices. This study evaluated four tillage treatments: wide level disc (T1), disc harrow (T2), chisel harrow (T3) and zero tillage (T4) on sorghum growth and yield over two cultivation seasons from 2022 to 2023 in Gombe State, Nigeria. A 4-ha field, divided into four subplots with uniform agronomic practices, was used to measure plant height, tillering, and yield at 2, 4, 6, and 8 weeks after planting (WAP). Early vegetative growth was enhanced by T2 and T3, with taller plants at 6 WAP, though differences largely disappeared by 8 WAP. In season 2, T3 and T2 increased yields by 43.6% and 33.4% over T1, respectively, while T4 showed more modest gains. These results highlight the importance of context-specific tillage strategies. For example, deeper chisel harrowing may be best suited to heavier soils, whereas shallower disc harrowing can optimize moisture retention, root penetration, and nutrient availability in drier, lighter-textured fields. Based on our findings, chisel and disc harrowing are recommended for enhancing sorghum productivity under semi-arid conditions.