Tillage effects on selected properties of an ultisol and adaptability of direct seeded upland rice in Abakaliki, Nigeria
Tillage experiment was conducted for two years (2006-2007) to monitor the effect of selected soil physicochemical properties of an ultisol and adaptability of direct seeded upland rice in Abakaliki. The experiment was established in a randomized complete block design (RCBD). The tillage methods investigated were two compaction passes with or without mulch, tillage with or without mulch and non-tillage with or without mulch. Results showed that soil compaction increased dry bulk density and surface resistance penetration of the soil. Tillage with mulch increased gravimetric water content and total porosity but reduced bulk density and soil surface resistance to penetration. The introduction of mulch in this study reduced bulk density in any of the tillage system, where it was applied. Root growth densities and grain yield were affected by the tillage system. The various tillage systems concentrated root development within the 0-10 cm dept of the soil. Compaction reduced root development at 20-30 cm depth. The tilled plots with mulch gave a 35% increase in grain yield in 2006 and 29% in 2007 over the no tilled plots without mulch. This showed that tillage with mulch plots gave better grain yield than plots without tillage both with mulch or no mulch.
Keywords: Tillage, mulching, tillering, physical soil properties, ultisol, grain yield, upland rice