Abstract

This study was conducted at the Grdarasha Research Station, College of Agricultural Engineering Sciences, Salahaddin University–Erbil, during the autumn season of 2024 to evaluate the impact of seeding rates on the growth, yield, and quality of two alfalfa (Medicago sativa L.) varieties: a local and an Italian cultivar. A factorial randomized complete block design (RCBD) was employed with three seeding rates (20, 40, and 60 kg ha⁻¹) and three replications. Key parameters assessed included plant height, number of branches, fresh and dry biomass, leaf/stem ratio, chlorophyll content, moisture content, and overall forage yield. Results showed that the Italian variety significantly outperformed the local one in terms of plant height (62.36 cm) and stem dry weight (7.67 g), while the local variety exhibited superior performance in number of branches (21.22), leaf dry weight (21.79 g), and leaf/stem ratio (4.97), indicating a more leaf-oriented growth pattern desirable for forage quality. Among seeding rates, the highest rate of 60 kg ha⁻¹ led to increased plant height (59.18 cm), fresh biomass (20.01 ton ha⁻¹), and dry yield (4.37 ton ha⁻¹), suggesting that higher density promotes productivity, although interactions with variety were evident. Significant variety × seeding rate interactions were observed for biomass yield, chlorophyll content, and moisture percentage. Notably, the local variety at 60 kg ha⁻¹ exhibited the best overall performance across multiple traits, underlining its adaptability and high yield potential under denser planting. The findings demonstrate the importance of optimizing both varietal selection and seeding rates to achieve maximum alfalfa production. These results can guide sustainable forage production practices in the Kurdistan Region’s agro-ecological conditions.