Responses of Melon (collocynthis Citrullus) and Soil Chemical Properties to Different N - Sources in Ado – Ekiti, Southwestern Nigeria

A two – year field experiment was conducted at the Teaching and Research Farm of the University of Ado – Ekiti, Ekiti State, Nigeria, during 2008 and 2009 cropping seasons to determine the effects of different N – sources on soil nutrient status and yield of melon (Collocynthis citrullus). The experiment was laid out in a Randomized Complete Block Design with three replicates. The different sources of N were: Calcium ammonium nitrate (CAN), Ammonium sulphate (AS), Urea (U), NPK 15 – 15 – 15 and control i.e. no fertilizer (NF). The results indicated that there were significant (P = 0.05) differences among the various N – sources with respect to their effects on soil nutrient status and yield of melon. The percentage decreases in soil organic carbon (SOC) after cropping were 58, 39, 49, 28 and 21 for NF, CAN, AS, U and N P K, respectively. Similarly, application of the different N – sources resulted in decreases in total nitrogen after cropping by 48, 26, 40, 14 and 7% for NF, CAN, AS, U and NPK 15 – 15 – 15, respectively. Averaged over two – years of experimentation, values of melon seed yields were 0.37, 0.61, 0.85, 1.22 and 1.15 t ha-1 for NF, U, CAN, NPK and AS, respectively.