Vol. 3, Issue 5, Part I (2017)

Abstract
Field experiment was conducted at the University of Calabar Teaching and Research Farm, Calabar in 2014 and 2015 planting seasons to evaluate the effect of different rates of organomineral fertilizer on soil properties, growth and yield of waterleaf in a degraded rainforest Ultisol in Southeastern Nigeria. Four rates of organomineral fertilizer (6, 8, 10 and 12 t/ha) and a control (no amendment) were laid out in a randomized complete block design (RCBD) with three replications. Results obtained showed that the application of different rates of organomineral fertilizer significantly increased (P < 0.05) soil pH, available phosphorus, basic nutrients (Ca, Mg and K), exchangeable acidity and base saturation status of the soil compared to control. There were significant differences (P < 0.05) among rates of application in plant height, number of leaves, number of branches, stem girth and fresh yield of waterleaf. Application of amendment irrespective of the rate of application enhanced waterleaf growth and yields more than the control. The fresh yield of waterleaf was significantly (P < 0.05) increased at all the growth stages measured (4, 7 and 10 weeks after planting (WAP)) as a result of the different rates of the amendment applied compared to the control. The mean fresh yields of 20.8, 24.6 and 24.9 t//ha obtained from plots treated with 12 t/ha of organomineral fertilizer at 4, 7 and 10 WAP, respectively were not significantly higher than the respective yields of 20.6, 23.8 and 23.7 t/ha obtained from 10 t/ha treatment. Therefore, the application of 10 t/ha of organomineral fertilizer is more appropriate for optimum production of waterleaf in a Rainforest Ultisol of Southeastern Nigeria.