Influence of tillage systems and nitrogen fertilizer levels on growth and yield of maize (<i>Zea mays</i> l.) hybrids

Abstract

Conservation tillage systems that maintain crop residues on soil surface is being suggested as an alternative to conventional tillage system that encourages soil erosion and decline in crop yield with time. Trials were conducted in 1993 and 1994 to investigate the effect of two tillage practices (conventional and no-tillage) and three nitrogen (N) fertilizer levels (0, 50kg N ha^-1 and 100kg N ha^-1) on growth rate and grain yield of maize hybrids (Hybrid 8522-2 and 8644-3) and TZPB-SR(check). At 0kg N ha^-1 under conventional tillage, growth rate varied from 0.44g-day^-1 at 0-10 days after planting to 1.12g day^-1 at 24-38 days after planting. Similar increases in growth rate were observed at 50kg N ha^-1 and 100kg N ha^-1. Significant interactions were recorded between tillage practices, hybrids and N-rates for grain yield. Grain yields of the varieties (hybrids and check) were significantly higher under conventional tillage practice than the no-tillage practice. Under conventional tillage, grain yield of the hybrids increased from 2.5t ha^-1 at 0kg N ha^-1 to 4.7t ha^-1 at 50kgNha^-1 for hybrid 8522-2 and then dropped significantly to 3.25t ha^-1 at 100kg N ha^-1. On the basis of grain yield, use of hybrid varieties are recommended and under conventional tillage practice.


Key Words: Conservation tillage; conventional tillage; growth rate; maize hybrids; grain yields


Moor J. Agric. Res. Vol.4(1) 2003:26-36