Integrated Application of Chicken Manure and KCl Enhances Growth and Yield of Shallot (Allium ascalonicum L.) on Peat Soil

Abstract

Peat soils present significant constraints for shallot cultivation due to poor nutrient availability and unfavorable physicochemical properties. This study evaluated the interaction and individual effects of chicken manure and potassium chloride (KCl) on shallot (Allium ascalonicum L.) growth and yield on peat soil. A completely randomized design with two factors—chicken manure (0, 250, 500, 750 g polybag⁻¹) and KCl (0, 0.8, 1.5, 2.2 g polybag⁻¹)—was used with three replications. The combined application of 750 g polybag⁻¹ chicken manure and 2.2 g polybag⁻¹ KCl produced the best results: plant height (39.67 cm), earliest harvest (62.17 days), bulb diameter (27.93 mm), bulbs per clump (7.50), fresh bulb weight (42.74 g clump⁻¹), dry bulb weight (33.03 g clump⁻¹), and lowest weight loss (22.77%), compared to control values of 26.50 cm, 70.33 days, 13.08 mm, 4.17 bulbs, 19.75 g, 9.87 g, and 50.01%, respectively. Chicken manure played a dominant role by supplying nitrogen and phosphorus while improving soil properties, whereas KCl supported assimilate translocation and bulb development. However, at the highest chicken manure level, additional KCl showed no significant effects, indicating nutrient saturation. These findings highlight that integrated fertilization with 750 g chicken manure and 2.2 g KCl per polybag effectively enhances shallot productivity on peat soils, emphasizing the importance of balanced, site-specific nutrient management.