Abstract

F. O. Adekayode and M. R. Olojugba

 The increasingly high cost of mineral fertilizers and a preferred economic disposal of wood ash had necessitated a research in the use of wood ash to reduce the rate of fertilizer application for maize production. The comparative effects of wood ash and NPK 15-15-15 on maize were investigated in Akure (70 15’N, 50 15’E), Nigeria in 2008. The four treatments investigated were 4 t/ha wood ash, 300 kg/ha NPK 15-15-15, 200 kg/ha NPK 15-15-15 plus 2t/ha wood ash mixture and a control plot without manure; while the land preparation was ploughed and harrowed once. Downy mildew resistant (DMR) open pollinated maize variety was planted at 60 × 30 cm in a randomized complete block experiment replicated four times, and the manure was applied in a ring at 10 cm from the maize plant. Pre- treatment soil analysis that entailed taking soil samples before the application of manure was carried out. Two maize crops were investigated and the means of data were computed for comparisons across treatments. The total leaf area per plant, leaf area index and the chlorophyll content were correlated to the grain yield. The profitable response was computed to confirm the economic viability. The chlorophyll content and the grain yield were significantly high in 200kg/ha NPK 15-15-15 + 2t/ha wood ash mixture and in 300 kg/ha NPK 15-15-15 compared to other treatments. Corresponding higher net revenues were also obtained which confirmed a mixture of wood ash and inorganic mineral fertilizers to be a suitable agronomic practice for profitable maize production.