The application of nitrification inhibior CP on the Citrus was studied by using the isotope technique.1. The rate of utilization of the nitrogenous fertilizer was increased when it was used in combination with the nitrification inhibitors.2. The number of the length of shoots
nitrogen content of leaf
amount of ammonium nitrogen pH in soil and the yield of fruit were increased
after the incorporation of nitrification inhibitor CP into nitrogenous fertilizer.3. There was no effect on the quality of fruits in citrus with the application of nitrification inhibitors. The residue of nitrification inhibitor CP in fruits of citrus was very low.