Conservation Agriculture combined with supplemental irrigation enhances resilience and food security in Morocco’s rainfed drylands

Abstract

Morocco’s rainfed drylands are highly vulnerable to recurrent drought and increasing rainfall variability, threatening wheat production and national food security. Conservation agriculture (CA) and strategic supplemental irrigation (SI) offer promising pathways to stabilize yields and improve water productivity in these fragile systems. This study evaluates the combined effects of CA and SI on grain yield, biomass production, and water productivity of wheat at ICARDA’s Merchouch research station during the 2021–2022 season under exceptionally dry growing season. A field experiment was established with two conventional tillage systems (CT) and conservation agriculture (CA)—combined with three water regimes: rainfed (no SI), one supplemental irrigation (20 mm at tillering, 25 January), and two supplemental irrigations (20 mm at tillering + 30 mm on heading). All irrigation was applied via drip, with scheduling guided by soil moisture status, crop stress, and dry spells. Results show that CA consistently outperformed CT across all water regimes. Under rainfed conditions, CA increased grain yield from 442 to 661 kg/ha (+49%) and water productivity from 2.04 to 3.06 kg/mm (+50%) compared with CT. With one SI, CA boosted grain yield from 845 to 1,484 kg/ha (+75%) and water productivity from 3.58 to 6.29 kg/mm (+75%). With two SI events, yields increased from 2,698 to 3,158 kg/ha (+17%) and water productivity from 10.14 to 11.87 kg/mm (+17%). Biomass and straw yields showed similar positive trends under CA, indicating improved overall system productivity. These findings demonstrate that combining CA with modest, well-timed SI can transform vulnerable rainfed wheat into a more productive and water-efficient system. If adopted at scale on suitable dryland areas, CA+SI has strong potential to narrow Morocco’s wheat yield gap, enhance climate resilience, and reduce dependence on imported wheat, thereby contributing directly to national food security.