The Vertical Distribution Characteristics of Carbon to Nitrogen Ratio in Soft Rock and Sand Compound Soil

Abstract

This study takes the soft rock and sand compound ratio communities located in Fuping, Shaanxi Province as the research object. Four treatments of soft rock and sand volume ratios of 0:1 (CK), 1:5 (C1), 1:2 (C2) and 1:1 (C3) were selected to analyze the relationship between carbon-nitrogen ratio (C/N) of compound soil and the soil nutrient and texture. The soil organic carbon and total nitrogen content decreased with the increase of soil depth under different treatments. The average organic carbon content ranged from 1.45-2.70 g·kg-1 and the organic carbon content of 0-10 cm soil layer was significantly higher than 20-30 cm soil layer, compounding ratio had a significant effect on organic carbon. With the increase of volume fraction of soft rock, the organic carbon content of 0-10 cm soil layer was the highest in C3 treatment. The average value of total nitrogen was between 0.28-1.31 g·kg-1, and the total nitrogen content of 0-10 cm soil layer was significantly higher than that of 10-20 cm and 20-30 cm soil layer. In the 0-10 cm soil layer, the total nitrogen content of C3 treatment was significantly higher than other treatments, and the compound ratio and soil layer had significant effects on total nitrogen. The average value of C/N was between 1.72-5.92, which was the lowest at 0-10 cm, and the value decreased with the increase of the volume fraction of soft rock, and the treatment with C3 was the most significant. When the ratio of soft rock to sand was 1:1, it can promote the accumulation of carbon and nitrogen in the surface soil of 0-10 cm and enhance the decomposition of microorganisms.