A Long-term field experiment was established at the University of Çukurova, Research and Application field of Agriculture Faculty on soil of Arıklı series at 1998. Four P doses like as; 0 (P0) as control, 50 (P50), 100 (P100) as well as 200 kg P2O5 ha-1 (P200) was applied with tree replications. Wheat of Adana-99 species (Triticum aestivum L.) seeds were sown in November 2018 and harvested at May 2019. After harvesting, plant sample and soil samples under different depth and places (0-15 and 15-30 cm soil depth in Rhizosphere and Non-Rhizosphere) were taken. Root, shoot and seed part of wheat and soil C and N sample analyzed by Fisher 2000 model CN analyzer. The Organic Carbon (OC) and Total N (TN) pools were calculated by Ortas and Lal, 2012. Obtained data statistically analyzed and LSD test were realized by JMP 8 computer package program. There was statistically significant difference as N% and C% concentration under P200 doses application. The heights C% and N% concentration was determined with P200 treatment. Also, there was statistically significant different as soil OC amount in Rhizosphere 0-15 soil depth in P 200 doses treatment in which the highest carbon content 46.1 Mg ha-1 was determined. In addition, soil total nitrogen was determined and the highest N was measured in 0-15 cm soil depth. Soil C:N ratio changing from 6.1 to 10.3 and the highest C:N ratio was determined in Non-Rhizosphere 15-30 cm soil depth. Under long-term field conditions, depending on increasing doses P fertilizer wheat plant growth and increased plant N and C concentration. Also, soil OC and TN amount were increased. It seems that the addition of P dose application increased biomass and consequently plant and soil C content. This is supporting our hypothesis.
Keywords: Long-term experiment, Phosphorus, Wheat, Soil Organic Carbon, and Nitrogen.