A laboratory experiment was carried out to study the kinetics reaction of zinc added to calcareous soils from different fertilizer sources and extracted by DTPA solution. Where two types of fertilizers were added, the first, nano-zinc fertilizers in the form of nano-metallic zinc oxide (ZnnO), nano-chelated zinc (ZnnDTPA), and nano-zinc humate (ZnnHA), while the second type was the same fertilizer sources, but in their regular form (ZnO, ZnDTPA and ZnHA). All of them were added at a concentration of 100 mg kg-1 and the nano and regular zinc sources were incubated after they were added to the soil to know their physical and chemical behavior during different incubation periods of 0, 5, 10, 20, 40, 80, 120 and 160 days, with two replications for each incubation period

Kinetics Reaction, Nano-zinc Oxide, Calcareous Soil, Kinetic Equations, Zn-DTPA