PERFORMANCE OF MAIZE AND SOYBEAN MIXTURE AS INFLUENCED BY ORGANIC MULCH IN THE SOUTHERN GUINEA SAVANNAH ZONE OF NIGERIA

Influence of different organic mulch materials on soil properties and on the growth and yield response of maize-soybean intercrop was investigated at the Teaching and Research Farm, University of Abuja. The mulch treatments used include; Centrosema pubescens , Sawdust, Rice husk and No- mulch. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications. Soil pH and Electrical conductivity were observed to have been lower under mulched plots. Soil organic carbon was generally low (1-9 g/kg) for maize while for soybean OC across mulch treatment ranged from 2- 17 g/kg; with the highest OC value (17 g/kg) recorded under sawdust. A significantly (P< 0.05) highest maize grain yield (1.01ton/ha) and stem diameter (10.3 cm) was observed under Centrosema pubencens while the least grain yield (0.66 ton/ha) was obtained under sawdust treatment. The highest soybean grain yield of 0.14 ton/ha was recorded under Centrosema pubescens treatment while the lowest grain yield of 0.12 ton/ha was recorded under sawdust treatment. The varied effect of organic mulch treatment on some soil characteristics and also on the growth and yield of maize - soybean mixture is a reflection of the effects of organic mulch on the microclimate of the soil. The organic mulch materials used include sawdust, rice husk and Centrosema pubescens . Sawdust was collected from a saw mill while rice husk was collected from rice mill both within the FCT Centrosema pubescens was collected from the University farm. The collected mulch materials were air dried to a constant weight prior to their measurement and application. Mulch treatment was applied at four (4) levels namely T 1- Centrosema pubescens (17 tons/ha), T 2-Sawdust (28 tons/ha), T 3- Ricehusk (28 tons/ha) and T 4- No-mulch (control) all at 3 WAS. The experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated four times. Routine weeding was done manually using a native hoe. The experiment was terminated 16 WAS.