effect of variation in tillage systems on maize (zea mays l.) establishment and grain yield in a semi-arid tropical climate

on-farm experiments were designed to investigate the response of maize establishment and grain yield to variation in tillage systems. the tillage treatments included arara ploughing followed by zig-zag harrowing and arara ridging (t1); emcot ploughing fol-lowed by zig-zag harrowing and emcot ridging (t2); mouldboard ploughing followed by disc harrowing and mouldboard ridging (t3); disc ploughing followed by disc harrowing and disc ridging (t4); manual ridging (t5). generally, shallow (0-15.0 cm) tilled plots of t1 showed lower root lengths and root length densities than deep (0.28.0 cm) tilled plots of t4. however, there was higher soil penetration resistance (pr) in t1 than in t4. in-creased pr in the range of 4.0 – 4.5 mpa decreased plant height (hp), leaf area index (lai), and maize grain yield (yg). reductions in yg in the range of 35 – 50% can be ex-pected for a reduction in soil moisture contents from 24.2 – 15.7%, w/w. tillage treat-ment significantly (p