Effects of combined application of inorganic fertilizer and poultry manure on growth and yield of sweet maize (Zea mays linn. var. saccharata) in Southern Guinea Savannah, Nigeria

Abstract

A field trial was carried out in 2014 cropping season at the nursery unit of the Kwara State Agricultural Development Project, Ilorin, in the Southern Guinea Savanna agro ecological zone of Nigeria. The aim of the study was to investigate the growth and yield responses of sweet maize to combined application of organic poultry manure and inorganic fertilizer. The treatments were: NPK 120 kgN/ha, Poultry manure (Pm) alone at 10 t/ha, 7.5 t/ha Pm + 90 kgN/ha, 5.0 t/ha Pm + 60 kgN/ha and 2.5 t/ha Pm + 25 kgN/ha. The control was without soil amendment. The treatments were arranged in a randomized complete block design and replicated three times. Among the treated plots, 5.0 t/ha Pm + 60 kgN/ha and 2.5 t/ha Pm + 25 kgN/ha were significantly lower in the grain weight and grain yield. The highest number of grains per cob (553.40) and thickest cob (14.18cm) were obtained at the treated plot where, 7.5t/ha Pm was combined with 90kgN/ha. There was no significant different in the grain yield between application of NPK at 120 kgN/ha and 7.5 t/ha Pm mixed with 90 kgN/ha. The study showed that combinations of poultry manure and inorganic fertilizer enhanced the growth and yield of sweet maize. Mixing inorganic fertilizer at 90kgN/ha and 7.5 t/ha, is recommended for adoption in sweet maize in the southern guinea savanna of Nigeria.