Effect of Irrigation Depths Using Soil Cover in Arugula (Eruca sativa) Cultivation

Abstract

Effective irrigation management is critical for maximizing crop productivity. This study aimed to investigate the effects of different irrigation depths and soil cover on the productive performance of arugula (Eruca sativa), a crop characterized by a shallow root system and high water sensitivity. The research was conducted in Viçosa, Minas Gerais, Brazil, using a Completely Randomized Design (CRD) in a split-plot scheme. Treatments consisted of two soil cover conditions (with and without polyethylene cover) and five irrigation levels (20%, 40%, 60%, 80%, and 100% of crop evapotranspiration), with four replications. Morphological development was evaluated by measuring plant height at 24 and 31 days after transplanting. Regression analysis at p < 0.05 revealed that soil cover significantly enhanced early growth, with covered plants averaging 3.97 cm taller than bare-soil plants at 24 days. This positive response is attributed to improved thermal stability and reduced evaporation. By day 31, irrigation levels became a dominant predictor of growth, exhibiting a quadratic response. Plant height increased with increasing irrigation from 20% to 60%, but declined significantly at 100% saturation. This decline indicates that over-watering leads to root hypoxia and nutrient leaching, inhibiting vertical elongation. No significant interaction effect was found between the two variables, suggesting the benefits of soil cover remain consistent across varying water depths. Optimal arugula production is achieved by maintaining moderate irrigation depths (40–60%) in combination with soil cover. This management strategy stabilizes the soil microclimate and maximizes water use efficiency, mitigating the risks of both water deficit and excessive saturation.