Abstract
A soil incubation experiment was conducted at the soil science laboratory of Akwa Ibom State University, Obio Akpa campus to evaluate the potentials of ground eggshell as a liming material in an acid sand soil of South eastern Nigeria. The experiment was laid out in a randomized complete block design (RCBD) with six treatments: 0, 0.2, 0.4, 0.6 and 0.8 tons of ground eggshell per hectare and 0.5ton/ha of calcium carbonate respectively as control. The experiment was replicated three times. For each treatment, a 100g of soil was added to plastic containers of equal size and basal diameter. The soil pH (in H20) and total calcium were determined on the incubated soil samples at 24 hours, and subsequently at 3, 6 and 9 weeks of incubation using standard laboratory procedures. The results showed that 8 tons per hectare of ground eggshell per hectare gave a constant change in soil pH up to 6.7, 6.5, 6.4 and 6.7 at 24 hours, 3, 6 and 9 weeks representing 28.4, 25, 25.6 and 30.7percents respectively over control. When compared with CaCO3 as control, application of lower rates reduced soil pH generally at different incubation times. Total calcium in soil increased generally at 24 hours, and in the 3rd and 6th weeks of incubation. Application of 0.8 tons per hectare of eggshell increased total calcium up to 1550, 231.66 and 104 percent over control. Lower rates of eggshell application reduced soil total calcium by 48.7, 30.6 and 26.4percents generally over CaCo3 control. The study has shown that eggshell has potentials to modify and amend acid sand of the study area. Application of 8 tons per hectare of ground eggshell is recommended for soil users in the study area.