K.K. Nyalemegbe*1 , G.K. Hots
Abstract
Experiments were conducted at Kpong and Kade that, respectively, represent the Coastal Savanna and Humid Forest ecologies of Ghana, to study the response of maize to Actyva fertilizer applications (N23 P10 K5 3S 2MgO 0.3Zn) in the two ecologies. The N23 P10 K5 3S 2MgO 0.3Zn fertilizer was compared with a no fertilizer control and the commonly used fertilizer, 16-6-16 NPK compound fertilizer basal application and top dressing with ammonium sulphate fertilizer or urea. The fertilizers were applied to the maize crop both in single and split applications. Rainfall in Kpong was high and well distributed in the Major Rainy Season but was low and poorly distributed in the Minor Season. At Kade, rainfalls in both the Major and Minor Seasons were high and well distributed. Organic matter content of soils in the Humid Forest ranges from 4.5 to 6% compared with 2% or less in the Coastal Savanna. The Actyva fertilizer applications in the Coastal Savanna gave significantly higher Plant Height, Total Dry Matter at harvest (TDM) and Grain Yield than the unfertilized control. On the other hand, no differences were observed in the Humid Forest, which had growth and yield values that were greater than observed in the Coastal Savanna. Plant Height at tasseling ranged from 317.1 cm to 335.8 cm at Kade, compared with 110 cm to 170.3 cm at Kpong. Grain Yield in the Major Rainy Season in the Humid Forest zone ranged from 3.71 t ha-1 in the control to 4.24 t ha-1 for Actyva at 100 kg N ha-1 (T3), compared with 1.87 t ha-1 to 3.12 t ha-1, respectively, at Kpong. Total Dry Matter was higher under the single fertilizer application than the split application, particularly at the highest levels of fertilizer application (i.e. Actyva at 200 kg N ha-1, T6 and 16-16-16 NPK fertilizer at 100 kg N ha-1, T9). However there was no grain yield difference between the single and split fertilizer applications. The split application of fertilizer thus gave higher Harvest Index than the single application.