Denitrification Capacity of the Widely Distributed Soil Series of the Turkish Republic of Northern Cyprus

Abstract

A laboratory experiment was carried out to determine the denitrification capacity of the Doganci, Geçitkale, Akdeniz, Balikesir, Pamuklu, Zümrütköy and Türkmenköy that are widely distributed soil series of Turkish Republic of Northern Cyprus. Soils are placed in anaerobic jars (20 % initial O₂, 80 % He) with addition of 300 mg kg^-1 NO₃^--N. Produced gases (CO₂, N₂ and N₂O) along with O₂ consumption were determined by gas chromatography. Moreover, ammonium and nitrate concentration of the soils were measured at regular intervals. The measured O₂ consumption and CO₂ production values as parameters of biological activities revealed considerable differences among the soil series studied. The more rapid O₂ consumption and the higher CO₂ production were determined in Balikesir, Zümrütköy and Türkmenköy soil series. Furthermore, O₂ level in the anaerobic jar was immediately dropped in early measurement intervals and was about 0 % at the end of the last measurement, particularly above mentioned soil series. The Zümrütköy soil series has higher CO₂ production in all measurement periods than the others and reached 975 μg CO₂ g dry soil^-1 at the end of experiment where others vary from 257 to 745. The measurements of N₂O and N₂ gases revealed that the most of the denitrification product consists of N₂. Additionally, the highest N₂O and N₂ productions were determined in the Balikesir series with 251 μg N₂O-N g dry soil^-1 and 498 μg N₂-N g dry soil^-1. When all series compared, there were significant differences for the production of N₂ and N₂O production. Nitrate and ammonium analyses measured in relation to time, ammonium content was similar in all series, however, nitrate content significantly decreased according to the measurement period.