Optimizing semi-arid wheat production through synergistic water and nitrogen management: Boosting yield, grain quality, and nitrogen use efficiency

Abstract

Bread wheat production in semi-arid Moroccan regions is challenging, due to water scarcity and inefficient nitrogen use. Consequently, optimizing water and nitrogen management is crucial to ensure sustainable yield and quality. This study aimed to evaluate the effects of varying nitrogen fertilizer rates and environment-specific irrigation regimes on the performance of the Moroccan bread wheat cultivar, focusing on yield, Nitrogen Use Efficiency (NUE), and grain quality. A randomized complete block design with three replicates was conducted across three INRA experimental stations: Sidi El Aidi (drip-irrigation), Merchouch (rainfed), and Afourar (gravitational: surface) irrigation. Three nitrogen rates were tested (N0: 0%; N1: 50% and N2: 100% of the recommended dose). The assessment included yield parameters, components of NUE, and grain and stem protein content. Under drought conditions, applying 50% of recommended nitrogen dose with supplemental drip irrigation, significantly improved yield components. Compared to rainfed and gravitational irrigation, drip irrigation enhanced grain yield by 78.24% and 62.50%, biomass by 59.96% and 61%, and grain number per m² by 45.43% and 75.00%, respectively. Nitrogen input mainly enhanced grain quality and NUE. Although higher nitrogen rates increased protein content, they significantly reduced NUE regardless of the irrigation regimes. Notably, NUE under drip irrigation was 65.6% and 109.0% higher than under rainfed and gravitational irrigation. Combining drip irrigation with 50% reduced nitrogen fertilizer is optimal for wheat yield, NUE, and quality under semi-arid conditions. This integrated strategy supports sustainable wheat production in water- and nitrogen-limited environments, promoting efficient resource use.