Field trials were conducted to examine the responses of Cassava, Maize and Pepper to fertilizers in the alleys of 3, 4 and 6 years oil palm fields. Fertilizers: NPK (1.44 kg/plot), Ferti Plus (9.68 kg/plot) and poultry manure (6.17 kg/plot) were applied two weeks after planting. Results showed that fertilizers significantly influenced N uptake and some indicators of N use efficiencies measured. NPK enhanced uptake and apparent recovery of N and Ferti Plus (organo-mineral fertilizer) and poultry manure promoted agronomic and physiological efficiencies of N use. Uptake and yields of N were higher for sole crops compared with intercrops across the fertilizers. Cassava and maize had enhanced N removed at harvest, Internal utilization efficiency (IE) and apparent recovery efficiency (RE), and pepper had higher IE, Apparent Recovery Efficiency (RE), Agronomic and Physiological Efficiency (PE) of N use. Age of oil palm fields and fertilizers influenced nutrient uptake and use efficiencies of the alley intercrop species. Nitrogen uptake and use efficiencies were highest for 4 and 6 years compared with the 3 years old fields across the intercrop species. NPK and Ferti Plus had higher efficiencies of uptake and use of N compared with poultry manure across the ages of oil palm fields. It is concluded that, alley intercrop species differed in uptake and use efficiencies of N. The alleys of oil palm of 1 to 6 years supported the performance of intercropped arable species and fertilizers enhanced soil nutrients and crop yields.