Intercropping in the Ouargla Oases under Saharan Conditions: Adoption, Diversity, and Vertical Stratification

Abstract

This study examines the dynamics of intercropping adoption in the Ouargla oases, identifying the determiningfactorsthat influence this practice and itsrole in enhancing the resilience of agricultural systems to climate and socio-economic change. Between September 2021 and April 2024, a surveywasconductedamong 180 farms in three areas (Ouargla, N'goussa, and Sidi Khouiled), using a structured questionnaire. The results show that 75% of farmsadoptintercropping, but there are significantdisparities: N'goussa has the highest rate (82%), followed by Sidi Khouiled (74%) and Ouargla (67%). Adoption ischaracterised by systematic practices in N'goussa (64%), irregular practices in Ouargla (47%), and balanced practices in Sidi Khouiled. A comprehensiveinventoryidentified 57 intercroppedspeciesacross the studyregion, including 21 vegetablecrops, 8 foddercrops, 7 condimentcrops, 11 fruittrees, 6 aromatic and medicinal plants, 2 industrialcrops, and 2 cereals. Speciesdiversityvaried by zone, with N'goussaexhibiting the highestrichness (54 species), followed by Ouargla (50 species) and Sidi Khouiled (48 species). Speciesdiversitydynamicsremained stable between 2022 and 2024, with 57 speciesrecordedin 2022, increasing to 59 in 2023–2024. Correlationanalysisrevealedthat adoption resultedfrom an integrated set of technicalfactors (spacing, treeage), humanfactors (farmerage, education, motivation), organizationalfactors (extension contact, creditaccess, professionalmembership), and socio-psychologicalfactors (personalbeliefs, social influence). Plant stratification remains essential for ecologicalbalance:two-stratum systemsaccounted for 37% of farms in Ouargla, 45% in N'goussa, and 48% in Sidi Khouiled. An innovative two-stratum model combining fruit trees and vegetablecropswithout date palmsispresent on 10% of farms in N'goussa, showcasing local farmers' adaptability. The findings highlight thatintercroppingremains a valuablestrategy for oasis sustainability;itswidespread adoption requirestargeted public policies, including extension services, creditaccess, training for youngfarmers, and the promotion of local diversification initiatives.