# Integrated effects of vermicompost and town refuse on growth and nutritional status of onion cultivated in calcareous soil

## TL;DR

This study shows that using vermicompost improves onion growth and nutrition in calcareous soil better than town refuse.

## Contribution

The study demonstrates that vermicompost at 20 ton fed-1 is more effective than town refuse in enhancing onion growth and nutritional quality in calcareous soils.

## Key findings

- Vermicompost at 20 ton fed-1 significantly increased chlorophyll, carotene, plant height, bulb diameter, and leaf area.
- Organic amendments elevated macronutrient and micronutrient concentrations and uptake in onion plants.
- Vermicompost improved oil content, soluble sugars, and protein percentage in onion bulbs more than town refuse.

## Abstract

This study investigates the influence of organic amendments vermicompost and town refuse on the growth parameters, nutrient uptake, and biochemical quality of onion (Allium cepa L) grown in calcareous soils. A pot experiment was carried out at Burg El-Arab City, Alex, Egypt. By using three levels (10, 15, and 20 ton fed-1) of both amendments compared to a non-treated control. Results indicated that the application of vermicompost, particularly at 20 ton fed-1 significantly enhanced chlorophyll a, b and carotene levels (0.086, 0.036 and 0.131mg g-1 FW) as well as growth indicators such as plant height, bulb diameter, and total leaf area (44.58 cm, 4.268 cm and 2.894 cm2. Both fresh and dry weights of bulbs and leaves increased notably with organic treatments. Macronutrient (N, P, K) and micronutrient (Fe, Zn, Cu) concentrations and uptake were significantly elevated by increasing amendment levels, with vermicompost showing superior results over town refuse. Additionally, the oil content (9.83%), total soluble sugars (TSS) (15.25%), and protein percentage (28.95%) in onion (Allium cepa L) bulbs improved remarkably under organic treatments. Strong positive correlations were found among most growth and nutrient parameters, indicating that enhanced nutrient availability translates directly to improve physiological and yield responses. The findings suggest that vermicompost is an effective and sustainable amendment for improving onion (Allium cepa L) productivity and nutritional quality under nutrient-poor calcareous soil conditions.