The effect of different nonwoven mulch applications on growth, yield, and morphological characteristics in spinach ( <i>Spinacia oleracea</i> ): a multi-year evaluation

This study was conducted to determine the effects of nonwoven mulch applications (single-layer, double-layer, and no mulch) on the growth, yield, and morphological characteristics of spinach (Spinacia oleracea L.) plants over a three-year period under open-field conditions. The experiment was a two-factor randomized complete block with year and mulch as factors. Parameters such as leaf number at harvest, aboveground plant and root fresh weight, plant height, leaf morphology, total leaf area, shoot-to-root ratio, specific leaf area, and compactness were evaluated. The year effect was a determining factor in many traits. In particular, aboveground plant fresh weight declined significantly, from an average of ~131 g in 2023 to ~90 g in 2025. Similarly, while the number of leaves was greatest in 2024 (≈17–18 leaves), it decreased significantly in 2025. The single-layer mulch was the most stable and best performing for most of the growth parameters, whereas the double-layer had a limiting effect on somPe traits. In conclusion, the nonwoven mulches had a significant positive effect on the growth and yield of spinach; however, the effects were strongly dependent on the environment during the growing season.