Effects of local liming materials on soil properties and yield of waterleaf (Talinum fructicosum (L.) Juss.) in an ultisol of southeast Nigeria

Soils of the tropics are generally acidic mainly due to the high and intensive rainfall that causes excessive loss of the basic cations. High soil acidity is often a limiting factor for plant growth. Liming is the most widely used method to neutralize acidity and improve crop performance. A field trial was conducted at two locations in the University of Calabar Teaching and Research Farm, Calabar, to determine the effects of local liming materials on soil properties and yield of waterleaf. Seven treatments consisting of wood ash (WA), oil palm bunch ash (OPBA), cocoa pod ash (COPA), periwinkle shell ash (PSA), cassava peels ash (CAPA), and carbide waste (CW), each applied at 8 t /ha, and a control (no lime applied) were laid out in a randomized complete block design with three replications. The result showed increase in soil pH from 4.5 before experiment to 5.93 in the plot treated with wood ash. Over all, soil organic carbon, available phosphorus, basic nutrients (Ca, Mg, K, Na) and base saturation were significantly (P < 0.05) increased in plots treated with lime materials. Plant height, number of leaves, number of branches, stem girth, leaf area, fresh and dry matter yield of waterleaf were all significantly increased. However, the highest mean fresh yield of 4.61 t/ha obtained from the WA treated plot was not significantly (P > 0.05) higher than the yield of 4.36 t/ha obtained from OPBA treated plots, but was higher significantly than other treatments. The fresh yield increase was 61, 58, 46, 45, 39 and 35%, while the dry matter yield percentage increase was 63, 56, 53, 50, 42 and 22 for WA, OPBA, COPA, PSA, CAPA and CW. Therefore, for amelioration of soil acidity and better crop performance in the acid Ultisol of Southeast Nigeria, application of either wood ash or oil palm bunch ash is recommended.