Response of maize to poultry manure and mineral fertilizer

The effect of mineral fertilizer, poultry manure, and their combination on maize was evaluated in a pot experiment. Six treatments viz 0, 4, 8, 12 tons of poultry manure (PM) ha-1, 60-40-40 kg NPK ha-1 (NPK) and 2 t PM ha-1+30-20-20 Kg NPK ha-1 (2 t + 1/2 NPK) were used in a completely randomized design. Root dry matter of the 2 t+1/2 NPK was greater than that of the 4 t ha-1 and control, and similarly to that of the NPK, 8 and 12 t PM ha-1 treatments. Shoot biomass showed a similar trend as the root dry matter. The NPK treatments and 12 t PM ha-1, rate had high shoot-root ratios. Although the NPK outyielded the other treatments in grain weight, it did differ significantly from that of the 2 t + 1/2 NPK, 8 and 12 t PM ha-1 treatments. Thousand grain weight values did not differ statistically among treatments. The harvest index indicated a higher efficiency of dry matter partitioning into the sink in the combined treatment than in the 4 and 8 t PM ha-1, rates. For practical purposes and from economic point of view, 4 t PM ha1 may be recommended while the combined treatment is promising. Poultry manure appeared more advantageous in supplying C and N to the subsequent crop as more C and N remain in the soil after the maize harvest than mineral fertilizer. The 12 t PM ha-1 rate retained over 40% more C than the mineral fertilizer rate. Further studies, especially in field situations, are recommended (au)