Cropping Systems Design under Different Climate Change Scenarios in Non-Tropical Drylands: A Case Study from Morocco

Abstract

Dryland agriculture in many countries faces increasing exposure to extreme temperatures, more frequent droughts, and greater rainfall variability, which reduces yield and increases production risk. This report synthesizes evidence on climate impacts and adaptation options in non-tropical drylands and derives climate-resilient cropping system designs considering Morocco as a case study. The cropping system design conceptual framework includes: i) a digital twin that combines harmonized inputs (climate, soils, management, and socio-economic constraints), ii) standardized indicators, iii) process-based crop simulation (APSIM) with climate ensembles, and iv) a decision-support layer that selects optimal cropping system designs, considering multi-criteria performance and robustness. Across crops, projections under the high-emissions pathway (RCP8.5) using APSIM Classic indicate larger yield losses in rainfed systems than irrigated; irrigation mitigates but does not eliminate climate-driven yield penalties. The Morocco case study (Settat-semi favorable rainfed) evaluated factorial combinations of (i) diversified rotations, (ii) conventional versus conservation tillage, and (iii) rainfed versus supplementary irrigation, including future climate scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) for Settat. Simulation results show that diversified rotations outperform cereal (wheat and barley)-dominated sequences by increasing biomass production, improving soil organic carbon (SOC) sequestration, and raising median wheat yields. conservation-tillage enhances soil water conservation and yield stability, with largest benefits in dry seasons. Supplementary irrigation reduced interannual yield variability, especially in the more climate-variable Settat environment, and interacts positively with soil improvements that reduce irrigation needs. Highest resilience arises by combining diversified rotations, no-tillage with residue retention, and targeted supplementary irrigation at critical growth stages—an evidence-based bundle for climate-resilient system design in Moroccan drylands.