Tillage effects on soil. Physical properties and sunflower (Heliantbus annuus) growth and yield in Ilorin, Nigeria.

Abstract

Soil physical properties and sunflower (Helianthus annuus) yield under convectional tillage (CT) and zero-tillage (Z,TJ. was monitored for 3 consecutive years in Ilorin, Southern Guinea Savannah zone of Nigeria (SGSZN). While bulk density of CT increased slightly over the years, significant decrease of 12 and 8% were observed in ZT at 0.1 and O.2m depths respectively. Also, soil moisture release at 50 kPa increased from 7.5 to l4m3m-3 for ZT and 10 to 12.5m3m-3 for CT. Infiltration rate increased by 13% over the 3 years in ZT and decreased by 12% in C,T. Sunflower plant height and stem diameter were unaffected by tillage (P = 0.05) significantly higher head diameter and seed yield were observed in CT for 1990 and 1991 (P = 0.05) while in 1992 no significant difference was observed in head diameter and seed yield among the tillage treatments (P = 0.05). It was concluded that sunflower growth under ZT may be beneficial to the fragile soils of the SGSZN.

Keywords: Tillage, sunflower, yield, Soil moisture release, Infiltration rates.