Liming and deep cultivation as long term mitigation actions to lower the rate of peat decomposition and CO2 emissions from peat soils

Abstract: Cultivated drained peat soils have a complex relationship towards CO2 emissions and the contribution to global warming. Many people are unaware that the CO2 emissions from peat soils, also known as organic soils, vary a lot within, and between, the fields. Permanent grassland may not always be the best mitigating action for lowering CO2 emissions. My research was done to provide a wider view on cultivated peat soils and the effects of long-term mitigating treatment towards slowing down the rate of peat decomposition and thus lowering CO2 emissions. The decisions regarding future use of cultivated peat soils should not be limited by incorrect information on the impact on climate change. The study was done by reviewing the literature together with labexperiments that measured the CO2 emissions from samples that had different treatments. The samples’ physical and chemical properties were examined as well. CO2 emissions were measured from undisturbed soil cores representing different treatments. The soil cores were collected in big lysimeters and small steel cylinders. The variables were differences in water content (lysimeter experiment) and altering water retentions (steel cylinders. I had too few samples and data for any statistically significant findings. But I observed differences between the samples and the treatments. The observations were brought to discussion and compared with findings in the literature to provide possible explanations as to how the CO2 emission could be affected. The water content is one of the main driving factors regulating the peat decomposition. Water content has a complex relationship to the physical and chemical properties of the peat soils and the effect on CO2 emissions. It affects temperature response towards microbial degradation as well as structure and abundance of microbial communities that are responsible for the degradation (CO2 emissions) of peat soil. This creates varying rates of peat decomposition and differences in CO2 emissions. I hope that this research provides more general information and wider views on the rate of peat decomposition and CO2 emissions from cultivated peat soils.