Effekten av olika brukningsmetoder på kolinlagring i åkermark

Sammanfattning: Increased carbon sequestration in agricultural land is an important measure to reduce global warming. Since the soil is a large carbon sink, a small change in the soil organic carbon (SOC) stocks can make a substantial difference to the carbon dioxide content in the atmosphere. An increase in SOC improves the soil health and fertility which in turn gives better yields and a more secure food supply. The purpose of this study is to examine the effect of an application of single and multiple methods in agriculture on soil carbon sequestration. This is achieved through a literature review and field study with analysis of soil samples. The result of this study shows that application of organic fertilizers increase SOC with 33,5% and application of both organic and inorganic fertilizers increase SOC with 27,9%. Organic amendments and cultivation of cover crops can increase SOC by 23% and 11% respectively. Agroforestry increases SOC by 18,3% but the effect varies in different climates. Generally, the results show a greater effect on SOC from an application of multiple methods rather than individual methods. For example, a combination of reduced or no tilling, organic amendments and cover crops can increase SOC by 50%. The analysis of soil samples shows a positive effect on SOC when using methods such as application of no till, cultivation of legumes and cover crops, organic fertilization and organic amendments. Significant effects between fields cultivated with these methods compared to control fields were found for soil water capacity, respiration rate and phospholipid content. In general, the greatest effects on SOC were found in fields with the highest number of combined methods. Future field studies should include more sample replicates from a wider time span to increase the accuracy of the assessment.