地理と自然災害のジャーナル
オープンアクセス

概要

Carbon sequestration in the soil fertilized with digestate as a method of mitigating the CO2

Katarzyna Wojcik Oliveira

The currently observed increase of the CO2 concentration in the atmosphere contributes to the global warming. Carbon sequestration is one of the ways to mitigate the CO2 emissions to the atmosphere. Soil can play a significant role in carbon retention and reduction of the greenhouse effect. On the other hand, soils especially degraded ones and that used as agricultural land require fertilization. One of the method of improving the fertility of the soils involves using the organic waste, which can be a valuable source of nutrients and has a positive effect on the physical and physicochemical properties of soils. The effect of digestate properties on carbon fate in soil were the aim of the study. The pot experiment with using slightly acid soil and two types of digestates, from the biogas plant and the anaerobically stabilized sewage sludge from a municipal wastewater treatment plant were conducted. The digestates were added to the soil in doses that increase the initial carbon concentration to 2% dry weight, and the pots which included the soil-waste mixtures and soil alone (as control sample) were incubated at 20C for 60 days in thermostated chamber. During the experiment the soil samples (in three repetitions) were taken four times, after the 1st, 3rd, 6th and 9th week. The significant decrease of organic carbon content were observed until the 6th week, and then the carbon content was stabilized. In the soil without amendments, the content of organic carbon did not change significantly.