A pot trial using maize (Zea mays, L.) grown on an Ultisol labelled with 32P was carried out to evaluatethe agronomic value of nine types of apatite rock phosphates and triple superphosphate. Results show that the effectiveness of tested rock phosphates is variable as compared to superphosphate, when measured at 30 days after planting. However, these rock phosphates were three to five times more effective than triple superphosphate in the second cropping.data.