Dry matter yield of okra and Nutrient Dynamics with cocoa pod husk-based compost and NPK fertilizer in an Ultisol

Abstract

Dry matter yield of okra with cocoa pod husk-based (CPH) compost was assessed in a pot experiment. Three CPH-based composts: CPH+Neem leaf (CPH+NL), CPH+Poultry manure (CPH+PM) and CPH+PM+NL at the rate of 25, 50, 75, 100 kg N ha-1 each and NPK fertilizer at 40, 50, 60 kg N ha-1 and control, were applied to 5 kg soil each with three replicates and arranged in a completely randomized design. Two varieties of okra (NH47-4 and LD88) were grown. Plant height, stem girth and number of leaves were measured at 6 weeks after sowing while dry matter yield (DMY) and nutrient uptake were determined. Pre- and post- cropping soil analyses were done. Data were analyzed using ANOVA and means separated by DMRT at α = 0.05. DMY for NH47-4 ranged from 6.5g (control) to 16.7g (NPK 60 kg N ha-1) and from 5.1g (control) to 7.5g (CPH+NL 100 kg N ha-1) while LD88 ranged from 8.3 g (control) to 19.1g (CPH+PM 75 kg N ha-1) and 4.0g (control) to 9.6g (CPH+PM75 kgNha-1 ) in main and residual planting respectively. The N, P and K uptake of NH47-4 and LD88 were significantly enhanced with fertilizer treatments compared to the control. After the residual planting, pH of soil ranged from 6.2 (control) to 7.0 (CPH+NL 50 kg N ha-1) with NH47-4 and 6.3 (control) to 6.9 (CPH+PM+NL 50 kg N ha-1) with LD88. Organic carbon ranged from 9.7 gkg-1 (control) to 22.7 gkg-1 (CPH+PM+NL 50 kg N ha-1) with NH47-4 and 13.9 gkg-1 (control) to 20.3 gkg-1 (CPH+PM+NL 50 kg N ha-1) with LD88. Total N ranged from 0.1 gkg-1 (control) to 0.8 gkg-1 (CPH+PM+NL 100 kg N ha-1) with NH47-4 and 0.1 gkg-1 (control) to 0.7 gkg-1 (CPH+PM+NL 75 kg N ha-1) with LD88. The P, Ca, Mg and Na were significantly increased with fertilizer compared to control. It could therefore be concluded that CPH-based compost could be a good fertilizer for okra growth and soil fertility improvement.