Effects of Tillage Methods and Nitrogen Fertilizer on Soil Properties and Performance of Yellow Oleander in Southern Nigeria

A study was conducted at the Research Farms of Biofuel Alternate and Renewable Energy Ltd, Edidi, Kwara State, Nigeria. Zero tillage, ploughing once and ploughing + harrowing and three rates of nitrogen fertilizer (0, 30, 60 Kg ha-1 Urea) were evaluated to assess their effect on soil physical and chemical properties and performance of Yellow Oleander (Thevetia peruviana (Pers.) Schum.). The experiment, designed as 3 x 3 factorial and fitted into randomized complete block design (RCBD) was laid out in split-plots and replicated four times. Ploughing once as against zero tillage and ploughing + harrowing produced higher values for plant height, number of primary branches, kernel number, kernel weight, N, P, K, Ca and Mg. The performance of ploughing once treatment was related to higher soil nutrient. Nitrogen fertilizer improved significantly the growth and yield of Thevetia when compared with the control. There were no significant difference in number and weight of kernel at 30 kg N ha-1 and 60 kg N ha-1. Due to the rising cost of fertilizer, ploughing once and application of 30 kg N ha-1 is recommended for Thevetia production in Nigerian southern guinea savann