Growth and Yield Response of Shallots (Allium cepa L.) on Sandy Soil Using Several Soil Ameliorant Compositions

This study aims to determine the best soil ameliorant composition that can improve the growth and yield of shallots (Allium cepa L.) in sandy soil, as well as to evaluate the effectiveness of weed and chicken manure ameliorant on the growth and yield of shallots. This study was conducted from June to September 2025 in Sungai Hitam, Beringin Raya Village, Muara Bangkahulu District, Bengkulu City, Indonesia, at an altitude of ±10 m above sea level. Soil analysis was carried out at the Soil Science Laboratory of Bengkulu University, Indonesia. This study used a Randomized Complete Block Design (RCBD) with one factor consisting of seven treatment levels, namely the composition of sandy soil, Ultisol, weed compost, and chicken manure. Data were analyzed using ANOVA, followed by a 5% Duncan Multiple Range Test (DMRT) and a 5% t-test. The results of the study indicate that the composition of the soil ameliorant has a significant effect on all growth parameters and yields of shallots, including plant height, number of leaves, number of bulb, average bulb diameter, largest bulb diameter, number of bulb per clump, fresh bulb weight, dry bulb weight, bulb weight loss, and bulb yield per hectare. The best composition for shallot growth and yield was obtained with a composition of 220 kg of sandy soil + 40 kg of Ultisol + 30 kg of weed ameliorant with the variables of plant height (32.40 cm), number of leaves (31.8), number of bulb (9.93), average bulb diameter (21.84 mm), largest bulb diameter (29.28 mm), number of bulb per clump (12.13), fresh bulb weight (138.28 g), dry bulb weight (110.88 g), dry bulb per plot weight (2772.08 g), and bulb yield per hectare (22.18 ton). In addition, the weed ameliorant composition had a better effect on the growth and yield of shallots compared to the chicken manure fertilizer.