Investigating the degradation of washed and untreated salty ‘Posidonia oceanica’, carob leaf compost, and commercial compost in a calcareous soil under anaerobic conditions

Abstract

The scope of this study was to analyse how different organic soil amendments affect the soil under anaerobic conditions. The trend of using commercial peat compost as a soil amendment has created a lot of environmental issues since it is imported from far away distances and its extraction requires the destruction of a vital habitat. In the Mediterranean, there is an abundance of ‘Posidonia oceanica’ residues which wash ashore on beaches, and carob trees (Ceratonia siliqua) that naturally produce fertile leaf compost. These materials could potentially offer sustainable alternatives to the commercial peat compost. This study aims to analyse the effectiveness of carob leaf compost (CLC), washed ‘Posidonia oceanica’ (WPOC), untreated salty ‘Posidonia oceanica’ (SPOC), and commercial peat compost (CPC) when added to calcareous soil under anaerobic conditions. The results indicated that CLC, WPOC, and CPC are all viable organic soil amendments, with WPOC showing to be the most suitable amendment in anaerobic conditions. While SPOC had poor parameters due to salt effects and high salinity, CLC demonstrated similar efficacy to CPC. This study highlights the potential of farmers and gardeners utilizing CLC and WPOC, as sustainable alternatives to CPC.