ASSESSMENT OF CARBON DIOXIDE EMISSIONS FROM DIFFERENT TILLAGE SYSTEMS

The article presents the assessment of energy input and carbon dioxide emissions from fuel combustion (in tractor engine) in different tillage systems. Although the carbon dioxide emissions from fuel combustion are not typically included in the greenhouse gas (GHG) emissions from agriculture, these emissions are directly related to crop production practices and use of machinery. The aim of this study is to evaluate and compare efficiency of the energy input and carbon dioxide emissions from the fuel combustion in winter wheat cultivation considering different tillage systems. The calculations are based on empirical data provided by Latvian crop farmers. In addition, the environmental cost of these carbon dioxide emissions is evaluated as the external (socio-economic) cost of the emitted carbon dioxide by applying the unit cost (unit shadow price) of carbon dioxide. The winter wheat is the most widely produced crop in Latvia, and the results of this case study imply that there is a potential both to improve the efficiency of energy input and to mitigate the emissions of carbon dioxide by reducing the intensity of tillage in Latvian crop production. Reduced tillage needs significantly lower energy input and causes less carbon dioxide emissions (33-46% on a per ha basis and 39-46% on a per tonne of wheat basis), as well as environmental cost than conventional tillage at the same time without significant differences in yields. Nevertheless, the debate on the long-term effects of conservation tillage systems on crop yields, crop diseases, weeds, etc. is open. Therefore, further research is required to assess other environmental aspects.