COMPARATIVE STUDY ON THE USE OF INORGANIC FERTILIZER AND ORGANIC MANURE ON THE GROWTH AND YIELD INDICES OF ONION (ALLIUM CEPA) IN DAMATURU, YOBE STATE, NIGERIA

Abstract

A field experiment was conducted at the Teaching and Research Orchard Farm of the Federal Polytechnic, Damaturu, Yobe State, to compare the effects of inorganic fertilizer and different organic manure sources on the growth and yield indices of two onion (Allium cepa L.) varieties (Red and White). The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Four treatments were evaluated: Inorganic fertilizer (NPK 15-15-15), Poultry manure (applied at 9 tons/acre), Cattle dung (applied at 9 tons/acre), and a Control (no amendment). Growth parameters (plant height, number of leaves per plant) and yield parameters (bulb diameter, total yield per plot) were collected and analyzed using SPSS. The results indicated that both organic and inorganic amendments significantly () improved the growth and yield of both onion varieties compared to the control. Poultry manure recorded the highest mean total bulb yield ( for Red and for White), outperforming NPK fertilizer and cattle dung. This study demonstrates that poultry manure provides an environmentally sustainable and economically viable alternative to synthetic fertilizers for onion production in semi-arid tropical soils.

Keywords: Allium cepa, Poultry manure, Cattle dung, NPK fertilizer, Yield indices, Semi-arid.