The Effect of Olive Pomace and Biochar on Soil Carbon Content and Some Physical Soil Quality Parameters

In this study, the effects of two different forms of olive mill waste, one of the industrial agricultural wastes, on soil carbon content and some physical soil quality parameters were investigated. In this context, olive pomace and biochar which is obtained from olive mill waste were applied to the soil at doses of 0, 0.5, 1.0 and 1.5 t da-1. Biochar from the slow pyrolysis process of olive pomace (500 ºC) was used in the study. Olive pomace and biochar applications caused significant differences in soil organic carbon (SOC), soil water content (SWC) and bulk density values. The effects of the applications on soil aggregate stability and aggregate formation were realized in different directions and levels at different aggregate sizes. Olive pomace was more effective than biochar, especially in the formation of macro-sized aggregates and the stability of aggregates. In both applications, there was an increase in SWC and SOC, and a decrease in the bulk density and penetration values. In the study, due to the 1.5 ton da-1 olive pomace and biochar applications do not make a significant difference compared to other application levels, it was predicted that 1.0 ton da-1 application level would be sufficient to improve physical soil quality. We observed an improvement in soil structure and related soil water budget which is of great importance in environments where meteorological and agricultural droughts are increasing and sustainable agriculture systems