No abstract

Oil mill wastewater (OMW) is the main liquid discharge from oil mills, it is considered as a dangerous pollutant due to its toxic chemical compounds which are unloaded directly in the environment without any treatment. The aims of this study were to evaluate the effectiveness of OMW adsorption on clay as a good method for the elimination of toxic chemical compounds and to study the application of treated OMW as an irrigation source in agricultural field. For this, Clay was collected from the city of Agourai (Meknes region, Morocco) and characterized by X-ray diffraction, X-ray fluorescence spectrometry, BET and FTIR analysis. Moreover, the treated OMW was analyzed using UHPLC-ESI-MS and the determination of total phenolic content (TPC) was also performed. However, the application of the treated OMW in agricultural field was performed by the determination of its effect on the germination of Lepidium sativum seeds (in vitro) and as a source of irrigation of Vicia faba plants (in situ). The results of this study showed that OMW had the following physicochemical characteristics: average pH of 4.88, TPC of 4.75 g/l, COD of 80 g/l, BOD5 of 18.72 g/l, conductivity of 16.05 cm-1, dry matter of 135.7 g/l and volatile matter of 58.7 g/l. The adsorption on clay had increased the pH from 4.88 to 6.14 and reduced significantly the organic matter (42% of COD and 57.4% of phenolic compounds). UHPLC-ESI-MS analysis showed the presence of a wide variety of organic compounds in OMW, with the appearance of new compounds after adsorption. Moreover, the use of treated OMW as a source of irrigation showed a significant effect on the germination of Lepidium sativum seeds and the growth of Vicia faba plants. From this study, we can conclude that the adsorption on clay is a good method for the treatment of OMW, which became non-toxic for environment and can be used as a source of irrigation in agricultural field.

This study focused on revealing the correlations between rock phosphate-solubilizing bacteria (PSB) counts and differing properties of the rhizosphere soil. One hundred and thirty-two samples of rhizosphere soil of faba bean (Vicia faba L.) were collected and analyzed from 14 agricultural areas in Meknes, Morocco. The results revealed that all the samples were inhabited with indigenous PSB ranging from 3.55 to 0.002 (×10 5 CFU/g soil). The correlations between PSB counts and cation exchange capacity, available phosphorus (P), and pH were insignificant; on the contrary, a highly significant correlation (p ≤ 0.01) was found between the numbers of PSB and total soil bacteria (TB) (r = 0.80), total nitrogen (N) (r = 0.86), and organic matter (r = 0.90). This research enhances our knowledge on PSB population and their interaction with physical, chemical, and biological properties of the rhizosphere soil of faba bean to provide a new index for better use in organic agricultural practices.

The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the subject of our study. Thus, a total of 30 sample trees were subjected to the weight measurements for the estimation of biomass and organic carbon stock in a logging lot in the Azrou forest. The amount of sequestered carbon was then extrapolated in all stand forests studied from the developed carbomass models. The results obtained show that the largest allocation of carbon stock (93%) is in the stem, followed by branches (5%) and foliage (2%). The average carbon storage in this cedar forest is 99.42 tC/ha (aboveground and belowground), or 364.58 t/ha of CO 2 , a value significantly higher than that found in other Moroccan forest ecosystems.

The study was carried out in the forests of the Central Middle Atlas where the soils have a Mediterranean character. The forest formations found include resinous species such as on Atlas cedar (Cedrus atlantica) and maritime mountain pine (Pinus pinaster), and deciduous species of green oak (Quercus rotundifolia) and zeen oak (Quercus canariensis). The morphological description of soils' genetic horizons was based on the opening of soil pedons in the forest formations composing the studied area. Then, physical and chemical characterization of the studied soils was analyzed. According to the Commission of Pedology and Soil Mapping (CPCS, 1967) principles and those of the international system of classification, nomenclature and soil mapping used by FAO (2015), three types of soils were identified as dominant in these forests, namely, the class of browned soils, iron sesquioxide soils and calcimagnesic soils. As a result, they differ in their responses to management practices, their inherent ability to deliver ecosystem services, as well as their resilience to disturbance and vulnerability to degradation.