Influence of compost supplemented with jatropha cake on soil fertility, growth, and yield of maize (Zea mays L.) in a degraded soil of Ilorin, Nigeria

Abstract

Purpose This study was conducted to determine the efect of compost supplemented with jatropha cake on maize (Zea mays L) yield in a degraded soil and their residual efects on soil fertility in Ilorin, Nigeria. Methods Field trials were conducted at Kwara State University Teaching and Research Farm, Malete, in 2016/2017 crop ping season. The treatments consisted of control, un-amended compost Grade B supplemented with Jatropha cake AJ (30% Grade B + 70% JC) at 1.5 t/ha, BJ (30% Grade B + 70% JC) at 2.0 t/ha, CJ (50% Grade B + 50% JC) at 2.5 t/ha including NPK at 60 kg N/ha. The treatments were arranged in a randomized complete block design (RCBD) and replicated three times. Results Maize grain yield (3.1 t/ha) was obtained from CJ at 2.5 t/ha this was signifcantly (p < 0.05) greater than that of NPK treatment (2.2 t/ha) after the frst cropping. At second trials, maize grain yield values gotten from CJ at 2.5 t/ha were also signifcantly (p < 0.05) greater than that of NPK values. Treatments CJ at 2.5 t/ha signifcantly (p < 0.05) improved soil pH, available P and exchangeable K. Conclusion Fertilizer 50% Grade B + 50% Jatropha cake at 2.5 t/ha had a signifcant and positive efect on soil fertility after harvesting of maize when compared with NPK in both cropping.