Citation: Vianney Nsabiyumva, J.M.; Apollonio, C.; Castelli, G.; Petroselli, A.; Sabir, M.; Preti, F. Agricultural Practices for Hillslope Erosion Mitigation: A Case Study in Morocco. Water 2023, 15, 2120. https:// doi.org/10.3390/w15112120 Academic Editors: Vito Ferro and Alessio Nicosia Received: 2 May 2023 Revised: 25 May 2023 Accepted: 30 May 2023 Published: 2 June 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). water Article Agricultural Practices for Hillslope Erosion Mitigation: A Case Study in Morocco Jean Marie Vianney Nsabiyumva 1,2 , Ciro Apollonio 3,4, * , Giulio Castelli 1,5,6 , Andrea Petroselli 7 , Mohamed Sabir 8 and Federico Preti 1 1 Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Piazzale delle Cascine, 18, 50144 Firenze, Italy 2 Polytechnic University of Gitega, Route Nationale No 8, km 4, Gitega BP 490, Burundi 3 Department of Agriculture and Forestry Sciences (DAFNE), Tuscia University, 01100 Viterbo, Italy 4 Associazione Italiana per L’Ingegneria Naturalistica (AIPIN), via San Bonaventura 13, 50145 Firenze, Italy 5 UNESCO Chair in Hydropolitics, University of Geneva, 66 Boulevard Carl-Vogt, 1205 Geneva, Switzerland 6 Environmental Governance and Territorial Development Hub (GEDT), University of Geneva, 66 Boulevard Carl-Vogt, 1205 Geneva, Switzerland 7 Department of Economics, Engineering, Society and Business Organization (DEIM), Tuscia University, 01100 Viterbo, Italy 8 National School of Forest Engineering, BP 511, Avenue Moulay Youssef, Tabriquet-Salé 11 000, Morocco * Correspondence: ciro.apollonio@unitus.it Abstract: In the last decades, the Rif area in Morocco has been frequently affected by soil erosion due to intense rainfall events. In order to help farmers improve their lives and avoid damages caused by this phenomenon, a management project (the MCA Project) aiming to grow fruit trees has been realized. The objective of this study was to evaluate, in three provinces of Morocco, the effect on the hydrological response of selected erosion control management techniques combined with olive tree plantations. The investigated variables were the final infiltration (If), the imbibition of rainwater (Pi), the runoff coefficient (Kr), and the soil detachment (D). In particular, for each investigated soil utilization, three replications of a rain simulation test (80 mm/h) and soil sampling were conducted. Results for surface conditions demonstrate that under vegetation in matorral and fallow, the surface is covered at more than 75% with a high content of organic matter (OM) at 4.5% and 2.6%, respectively. Despite the compaction observed in those land uses, the surface area opened exceeded 90% in the study area. Regarding the soils physical properties, they were rich in silt at more than 40%; the rate of porosity is high where bulk density is low. At the Taounate site, low porosity was at 62% in fallow and at 55% in plowing, with high densities of 1.01 g/cm 2 and 1.2 g/cm 2 , respectively. Tests also demonstrate that vegetation has an important role in moisture conservation in the depths of 0 to 10 cm at all sites with macroagregate stability (MA%) compared to plowing sites. In terms of soil hydrology, vegetation reduces the runoff because, under matorral (it was at 0%), it avoids soil erosion. Keywords: erosion control management; hydrological parameters; runoff risk; Rif; agro-sylvo- pastoral systems; olive trees; agroforestry; soil erosion management; Mediterranean 1. Introduction In the Mediterranean basin, soil erosion due to intense rainfall events, i.e., water erosion, is one of the major processes of land degradation, hence constituting a great source of desertification [1]. Moreover, there is an increasing trend of aridity that accelerates such a process [2]. According to FAO studies [3], water erosion affects 50% of the soil in Turkey, 40% in Morocco, and 35% in Greece. The factors favoring water erosion in this area are generally the fragility of the soil, the irregularity of intense rainfall events, the soil slope, the high air temperatures, which accelerate the mineralization of organic matter, and the vegetation cover reduction caused Water 2023, 15, 2120. https://doi.org/10.3390/w15112120 https://www.mdpi.com/journal/water