DYNAMICS OF CARBON, NITROGEN, PHOSPHORUS AND POTASSIUM UNDER DIFFERENT Tithonia diversifolia MANAGEMENT SYSTEMS IN A TROPICAL ALFISOL: A GREENHOUSE BIOASSAY

Abstract

The research investigated the dynamics of C, N, P and K under different Tithonia management options.Changes in soil N and P showed significant increase in these nutrients in treatment with incorporatedTithonia + NPK and Mulched Tithonia + NPK respectively. There was a reduction in the soil K at6 WAP in all the treatments except those with NPK and mulched Tithonia. Generally, there was a sustainedincrease in soil organic carbon in all the treatments. There was an increase in N and P contentsof maize plant with successive cycles thus indicating residual effect, most pronounced in treatmentwith incorporated Tithonia + NPK. However, there is the need for K supplementation at the secondmaize cycle. Maize biomass yield indicated the possibility of two cycles with mulched or incorporatedTithonia + NPK fertilizers as most promising option. Economic feasibility should, however, be considered.