173 INTRODUCTION The soil is a key component to provide many important ecosystem functions. It is a complex substrate, physically and chemically heteroge- neous, that supports a high diversity of micro- bial and faunal taxa, provides food and biomass production, and plays a major role in climate regulation (Larson and Pierce, 1991; Meng et al., 2017). Therefore, the sustainable management of soils requires a regular assessment of their status through the measurement of soil quality indicators. Farm management practices, such as crop rotation, tillage, and fertilization, modify soil properties in the mid-and long-term. Hence, these practices have an impact on crop develop- ment and productivity, and on the agricultural system.s sustainability (De La Fuente and Suárez, 2008; Zubeldia et al., 2018). Over the decades, intensive agricultural prac- tices and the unbalanced use of fertilizers have led to soil quality loss. Alternative systems such as no-till (NT) have emerged as a soil conservation strategy (Masto et al., 2008; Bilgili, Küçük and Tillage, Residues Management, and Nitrogen Fertilization Efects on Soil Organic Status, Soil Quality, and Soft Wheat in the Moroccan Semi-Arid Hiba Et-Tayeb 1* , Khalid Ibno Namr 1 , El Houssine El Mzouri 2 , Bouchra El Bourhrami 1 , Rachid Moussadek 3 1 Geology Department, Geosciences and Environmental Technics Laboratory, Chouaib Doukkali University, Faculty of Sciences, Route Ben Maachou, B.P. 20, 24000 El Jadida, Marocco 2 National Institute for Agronomic Research (INRA), BP589, 26000, CRRA Settat. Morocco 3 National Institute for Agronomic Research (INRA), PB 6570, 10101, CRRA Rabat. Morocco * Corresponding author’s e-mail: ettayeb.h@ucd.ac.ma ABSTRACT Sustainable management of agricultural practices can improve soil organic status, soil quality (SQ), and yields. The study was conducted to test the impact of tillage (conventional (CT) and no-till (NT)), residues (vetch (C 1 ) and uncover soil (C 0 )), and three nitrogen (N) fertilization rates (30, 60, and 90 N kg ha -1 ) on soil organic carbon (SOC), total nitrogen (N), C/N ratio, soft wheat yields and SQ. The experiment was established in 2010 in the Moroccan semi-arid. After ten years, the SOC concentration was greater under NT (9.4 g/kg) compared to CT (8.4 g/kg). Crop residues also enhanced SOC (10 g/kg) contrary to C 0 (8.1 g/kg). Application of N fertilization showed profound efects on total N, increasing levels of N fertilization led to higher total N irrespective of tillage. Crop residues increased total N (0.6 g/kg) better than C 0 plots at the horizon 20–40 cm. Soft wheat revealed an improve- ment under NT (4213.8 kg ha -1 ) versus CT (3785.6 kg ha -1 ) and it responded positively to the N application. For SQ evaluation through the indexing methods (SQI), principal component analysis was done for eight soil indicators to select the minimum data set (MDS), which were subsequently normalized and integrated into the SQI, additive (SQI ANL ), and weighted (SQI WNL ). NT revealed higher scores (0.52; 0.6) than the CT (0.46; 0.53) for SQI ANL and SQI WNL , respectively, at the horizon 0–20 cm. the residues layer on the soil surface improved SQI WNL score (0.59) compared to C 0 (0.55). Moreover, the correlation (r) with yield and the sensitivity (S), allowed us to choose SQI- WNL , as the best index (highest r and S) to evaluate SQ under diferent practices studied. Indeed, SQI WNL revealed an intermediate SQ under NT and at C 1 treatments, compared to CT and C 0 (low SQ). Keywords: no-till, residues; total organic carbon, total nitrogen, soil quality, soil quality index, semi-arid, Morocco. Received: 2022.01.01 Accepted: 2022.01.19 Published: 2022.02.01 Ecological Engineering & Environmental Technology 2022, 23(2), 173–184 htps://doi.org/10.12912/27197050/145962 ISSN 2719-7050, License CC-BY 4.0 ECOLOGICAL ENGINEERING & ENVIRONMENTAL TECHNOLOGY