Use of olive pomace as an amendment to improve physico-chemical parameters of soil fertility
¹Mohammed V University, High School of Technology, Civil Engineering and Environment Laboratory (LGCE), Materials Water and Environment team, MA11060 Sale, Morocco
²INRA, Regional Center for Agricultural Research in Rabat, Research unit on Environment and Conservation of Natural Resources, MA10112 Rabat, Morocco
Given their richness in nutritive elements, the majority of agricultural waste is used as soil amendments, including olive oil waste. The purpose of this study is to determine the effects of the use of olive pomace from three extraction systems on the physico-chemical fertility of the soil, after their use as an amendment for faba bean cultivation. The experiment is carried out at the Civil Engineering and Environment Laboratory in the EST of Salé, in pots where the olive pomace has been mixed with the soil, respecting the percentages studied. Several relative physico-chemical parameters of soil fertility were determined at the end of the experiment, namely pH, electrical conductivity (EC), total kjeldhal nitrogen (NTK) content, organic carbon and exchangeable bases concentration and soil cation exchange capacity (CEC) determination. Different percentages of pomace from the three extraction systems were applied (control, 10%, 15%, 25%, 50%, 75% and 100%) for four months of bean germination test. The application of the pomace reduced soil pH, and increased soil organic matter and organic carbon content in proportion to the added percentage of pomace. The available phosphorus and exchangeable potassium content increased significantly (p < 0.05) in pots containing different percentages of pomace compared to their concentrations in the soil (control). The total nitrogen content has not increased sufficiently but remains significantly different from the control, especially for the percentages of 25%, 50% and 75%. For its part, the cation exchange capacity (CEC) is important and will allow a good retention of nutrients for all percentages.