Comparative assessment of physicochemical properties, functional diversity and enzymatic activities in three Opuntia ficus-indica soils across diverse climatic regions in Morocco

Abstract

In Morocco, Opuntia ficus-indica is grown in various climatic zones, each of which can greatly impact the soil quality and functioning. This study assesses the soil characteristics, bacterial load, functional microbial diversity, and enzymatic activities in O. ficus-indica soils from three distinct regions: Tafrant (subhumid), Fez (semi-arid), and Chichaoua (arid). Soil samples from these regions exhibited varying physicochemical properties, with neutral to alkaline pH, high concentrations of K, Na, and Ca, and biological activities, including microbial metabolic preferences and enzymatic activities. The data analysis and principal component analysis (PCA) revealed significant correlations in O ficus-indica soils across three regions of Morocco. In the subhumid region of Tafrant, there was a notable correlation between Shannon evenness index, amino acid metabolism by the microbial community, and β-galactosidase activity, with high levels of Fe, NH₄⁺, and Cu. Conversely, in the semi-arid region of Fez, strong associations were observed between organic matter content, Mg, P, NO₃-N, and increased microbial load, average well color development (AWCD), carbohydrate and polymer metabolism, and elevated phosphatase activity. The arid region of Chichaoua exhibited a distinct correlation between K and Zn levels, urease activity, and the metabolism of amines and amides substrates. Our results highlight distinct variations in the physicochemical properties, microbial community function, and enzymatic activities of O. ficus-indica soils across the three Morocco's regions. These findings highlight ecosystem uniqueness and offer key insights for biodiversity conservation and soil fertility management.