Effects of Composting on Three CPH Based Fertilizer Materials Used for Cocoa Nursery

Abstract

In its raw or processed form, CPH has the potential to be used as organic fertilizer but few studies have been conducted in Nigeria. This study was designed to examine the utilization of CPH as organic fertilizer to raise cocoa seedlings in nurseries. In this study, composite was made using CPH only and 1:1 v/v of CPH and Goat dung (GD) to mixture by weight. Raw CPH was allowed to decompose naturally. Exhausted soil devoid of any amendment was used as control. The three composite were monitored for 54 days and were used for cocoa seedling production using 25, 50, 100 and 200 kg ha^-1 application rates with four replicates each for 10 weeks. The composted CPH only, showed that it contained 4.9%Nitrogen, 0.6%Phosphorous, 3.6%Potassium, 33.3%Carbon and 17.0% moisture while the uncomposted CPH contained 2.7%Nitrogen, 0.1%Phosphorous, 3.0%Potassium, 31.8%Carbon and 11.7% ash content indicating that composting enhanced Nitrogen, Phosphorous, Potassium and Carbon contents. However, composted CPH+GD (1:1 v/v) contained 5.9%Nitrogen, 0.5%Phosphorous, 4.1%Potassium and 22.0% moisture. Composting thus improved Carbon, Nitrogen, Potassium and moisture contents as compared to composted CPH only and uncomposted CPH (control). The effects of composted CPH+GD (1:1 v/v), composted CPH only and uncomposted CPH on the plant height (16.1cm, 7.5cm and 9.5cm), stem girth (2.6cm, 1.6cm and 1.4cm) and number of leaves (10.5, 5.9 and 5.6) of the planted cocoa seedlings at the tenth week after planting showed that composted CPH+GD (1:1 v/v) medium was highest and significantly different (P<0.05) from those grown on composted CPH only and uncomposted CPH. Application rate of 200 kg ha^-1 supported the highest plant height (15.5cm), stem girth (3.1cm) and number of leaves (11.0) of cocoa seedlings than the lower rates, which were not significantly different from themselves. Nevertheless, the performance of the seedlings raised on composted CPH+GD (1:1 v/v) suggests its potential as a good organic fertilizer for cocoa nursery.