The effects of green manure and NPK fertilizer on the growth and yield of maize (Zea mays L) in the mount Cameroon region

This study was carried out in the Mount Cameroon region to evaluate the effects of green manure and fertilizer on the growth and yield of maize. There were eight treatments: Calliandra prunings, Calliandra prunings + fertilizer (60kg/ha NPK), Gliricidia prunings, Gliricidia prunings + fertilizer, Senna prunings, Senna prunings + fertilizer, fertilizer only (120 kg/ha NPK) and control. Results showed that biomass of prunings in the first pruning was highest in Calliandra (5314kg/ha) and this was significantly different from those of Senna (2909kg/ha) and Gliricidia (2112kg/ha). Nitrogen input from the prunings was highly significant (P<0.05) in Calliandra prunings (217 kgN/ha) and least in Gliricidia species (69.0kgN/ha). Maize grain yield in the different treatments was not significantly different in the first and second planting seasons. The highest grain yield during the third cropping season was observed in Calliandra + fertilizer (4696kg/ha) and least in control (3332kg/ha). It was also noted that nitrogen uptake was highest in plots supplied with fertilizer only and lowest in control. Weed biomass was highest in control and in plots supplied with fertilizer only. Soil chemical changes after three cropping periods showed variable changes in treatments. There was decrease in bulk density in plots supplied with Calliandra prunings.