Institute of Field and Vegetable Crops, National Institute of the Republic of Serbia Agricultural Institute of Slovenia (KIS) Carbon Sequestration by Composting around Mount Etna Latvian State Forest Research Institute „Silava“ Institute of Sustainable Development of Landscapes of the Earth e.V. (DUENE) Naturland e.V. Agricultural Institute of Slovenia Institute of Field and Vegetable Crops Manfred-Hermsen-Stiftung „Green Jackets“ Bronte