Is parent material an important factor in soil carbon and nitrogen mineralization?

Abstract

Conversion of rocks and organic inputs to parent material and soil is a dynamic process controlled by physical, chemical and biological factors. Soil samples were taken from different parent materials (gypsum, marl and serpentine) in Ankara, Turkey to observe how the properties of parent material reflect on some soil characteristics. Their carbon (C) and nitrogen (N) mineralization were respectively determined by CO2 respiration method and the Parnas-Wagner method under the controlled laboratory conditions for 42 days (28 °C, 80% of field capacity). Soil CO2 respiration showed that there were significant differences between each parent material after 42 days of incubation as following: marl > gypsum > serpentine. Soil C mineralization rate in marl was the highest among the other two soils. NH4-N contents and net N mineralization of soils were significantly highest at the 11th day compared to 26th and 42nd days in all soil types (P < 0.05). NO3-N contents were statistically different from each other in the serpentine soil at all of three times (P < 0.05). Generally, no significant differences were found between soils in all N mineralization parameters in each time of incubation. Our findings showed that soil carbon mineralization was affected by the differences in parent materials, their physical and chemical properties such as texture, pH, CaCO3, C and N contents. It can be concluded that response of soil microorganisms in carbon mineralization is more active than in nitrogen mineralization in all soil types due to a low nitrogen content.