Biochar is an organic regulator that improves crop yield by regulating soil properties. In addition, this organic regulator is also effective in reducing CO2 emissions from soil. However, considering the management of CO2 emissions together with many factors and the different properties of soil depending on the biochar content, CO2 emissions can vary. Thus, the study investigated the soil moisture and temperature and H2O emission, which affect the emission, and CO2 emission of biochars with different raw materials applied to the soil in the wetting–drying cycle of the soil. It was determined that biochar applications decreased CO2 emissions, but the share of each biochar material in reduction differed, and CO2 emissions were 82, 51, 20, and 13% lower in straw, hazelnut, apple, and sawdust biochar applications than in soil without biochar, respectively, and significant positive linear relationships of CO2 emissions with soil moisture–temperature and H2O emissions were determined. In addition, in biochar applications, H2O and soil temperature decreased depending on the moisture retention in the soil increased. In the findings, it can be suggested that straw biochar application to soil is more effective in reducing the severity of increasing global warming, and that soil moisture and temperature should be managed to reduce CO2 emissions.
Biochar treatment decreased the CO2 emission from the soil.
Straw biochar caused lower CO2 emission compared to hazelnut, apple, and sawdust biochar.
Biochar treatment decreased H2O emissions and soil temperature, while increased soil moisture.
The relationships of CO2 emission with soil moisture, H2O emission, and soil temperature were positive linear.