ABSTRACT

Investigation on the effect of biochar, poultry manure and NPK 15:15:15 fertilizer on some soil chemical properties and yield of maize (Zea mays L.) in an L'ltisol in Umudike was conducted in 2016. There were seven treatments consisting of biochar (lOtons/ha), poultry manure (10to.ns/ha), NPK 15:15:15 fertilizer (400kg/ha), biochar (5tons/ha) + NPK 15:15:15 fertilizer (200kg/ha), poultry manure (5tons/ha) + NPK 15:15:15 fertilizer (200kg/ha), biochar (2.5tons/ha) + poultry manure (2.5 tons/ha)+ NPK 15:15:15 fertilizer (lOOkg/ha) then the control. The treatments were replicated three times in a randomized complete block design. Maize variety (Oba Super 11) was used for the study. The result of the study showed that all treatments significantly (P<0.05) increased the soil chemical properties but, biochar 2.5 tons/ha + poultry manure 2.5 tons/ha + NPK 15:15:15 fertilizer lOOkg/ha gave the highest value. The biochar 2.5tons/ha + poultry manure 2.5tons/ha+NPK 15:15:15 lOOkg/ha fertilizer reduced the soil acidity by increasing the soil pH from 5.40 to 6.27 and increased most of the soil chemical parameters such as; the soil organic matter from 1.59% to 4.03%, percentage total nitrogen from 0.06% to 4.03%, available phosphorus from 18.0 mgkg-1 to 51.4 mgkg-1, potassium from 0.26 cmolkg-1 to 0.36 cmolkg-1, magnesium from 1.80 cmolkg-1 to 3.30 cmolkg-1 base saturation from 88.82% to 97.70%, with the control giving the lowest value in all the chemical parameters. Likewise for the yield of maize, all the treatments significantly (P<0.05) increased the yield of maize. Treatment (7) gave the highest number ofmaize cobs (45,566 /ha) and maize yield (14.33 t/ha-1) while the control treatment gave the lowest number of maize cobs (26,667 /ha) and maize yield (4.07 t/ha-1). Therefore the incorporation of biochar+poultry manure+NPK 15:15:15 fertilizer is recommended to increase the soil chemical properties and profitable yield ofmaize in the Ultisols of Umudike.