*2.3. Sample Collection and Preparation*

At least 1 kg of topsoil (a depth 0–10 cm) was collected on the day after planting (DAP 0—days after planting), 34 days after planting (DAP 34), and 48 days after planting (DAP 48) using a soil sampling auger (diameter, 2.3 cm; and height, 10 cm). The soil samples were sieved using a <2 mm diameter sieve, and then stored at −20 ◦C until analysis. The moisture content of soil samples was determined by calculating the difference in soil weight before and after drying at 105 ◦C for 24 h. Scallion samples were collected on the 20, 27, 34, 41, and 48 days (100% mature) after planting (DAP 20, 27, 34, 41, and 48). The individual weight and height of each sample were measured to compare the growth status at the time of sample collection. After removing the root of the scallion and adding dry ice, samples were homogenized using a blender (Blixer® 2, Lobot Coupe, Montceau-les-Mines, France), and then stored at −20 ◦C until analysis.
