Enhancing Potato (Solanum tuberosum L.) Production in a Semi-arid Environment in Morocco Using Subsurface Drip Irrigation and Other Water-Saving Strategies

The Fès-Meknès region in Morocco is characterized by a typical Mediterranean climate and the cultivation of water-demanding, locally well-established cash crops, such as potato ( Solanum tuberosum L.). Therefore, this region is likely to experience considerable water conservation benefits following implementation of Subsurface Drip Irrigation (SDI) technology alongside other water management strategies. To investigate this potential, we conducted a field trial comparing surface Drip Irrigation (DI) and SDI, combined with Regulated Deficit Irrigation and mulching as additional water-saving measures. Establishing potato crops solely with SDI proved challenging, leading to non-uniform germination and a 25% yield reduction at the plot level compared to DI. Tuber quality concerns, including disease infestation and malformations due to soil moisture fluctuations, may pose another drawback of SDI. However, plant measurements during the growing season and at harvest suggest that once established, potato plants benefited from the underground water and nutrient source, particularly later in the season, as indicated by (i) higher chlorophyll content; (ii) increased biomass at harvest; and (iii) 20% higher tuber yield from mature individual plants. Despite the initial establishment challenges, this highlights SDI’s potential for improving late-season crop performance. Mulching did not result in any yield effects. Drawbacks for mulch application such as seed contamination and nitrogen immobilization were observed. While Regulated Deficit Irrigation increased plant water stress under hot and dry conditions, as shown by reduced stomatal conductance, it did not significantly impact yield. Thus, strategically reducing irrigation amounts saved 12% water without compromising productivity.