1 Loess was the parent material of Lou soil in Guanzhong In the monsoon climate of the warm temperate zone there was an obvious Calcic horizon and Argic horizon in the middle and lower part of Lou soi

Loess is the parent material of Lou soil found in Guanzhong. Lou soil profile exhibits an obvious Calcic horizon and Argic horizon in the middle and lower parts, due to the monsoon climate of the warm temperate zone. The long-term anthropogenic bedding activity has resulted in the formation of Cumulic epipedon on the surface. The profile configuration is mainly A-B or A-B-C, and the overburden layer (Aup+Aupb) of the upper section contains intrusive bodies such as carbon slag and tile. The soil texture is primarily silty loam and silty clay loam, with a noticeable difference in color between dry and moist sections. Soil dry tone mainly ranges from 2.5Y to 10YR, while the moist tone falls between 2.5Y, 5Y, 7.5YR, 10YR, and 2.5GY. Pseudo mycelium or cream-like lime aggregates, clay adhesive film, humus adhesive film, and new bodies of the tattoo class can be observed in the profile. The pH value of the soil is alkaline, ranging from 6.3 to 9.50, and the soil bulk density ranges from 0.64 to 1.75g cm-3 with an average value of 1.20g cm-3. The soil organic carbon content is between 1.67 and 20.5g kg-1, total nitrogen content is between 0.257 and 2.19g kg-1, and the available phosphorus content is between 0.182 and 229.66mg kg-1. The accumulation degree of CaCO3 in the test section varies, with content ranging from 5.79 to 263.74g kg-1. The content of the pile cushion is higher than that of the lower layer, indicating a decreasing trend from top to bottom.