Terraced fields increased soil organic carbon content in croplands of the loess plateau

Terracing is widely distributed in mountainous and hilly areas worldwide to increase grain production, control soil erosion, increase soil moisture, and improve soil quality, potentially impacting soil carbon pools. This study investigates how agricultural activities and ecological restoration measures affect soil carbon pools in terraced areas of the Chinese Loess Plateau. We established an observation system in typical terraces and collected soil samples from 0 to 100 cm depth in terraces with different crops and ecological restoration vegetation. Our results show that terracing effectively increases soil organic carbon (SOC) content, with terraced cropland (7.7 g kg^{- 1}) having higher SOC than sloping cropland (4.9 g kg^{- 1}), In the 0-100 cm layer, SOC content in terraced wheat fields was 1.5 times higher than in sloping wheat fields, with the most significant increase in the top 0-30 cm. This increase is attributed to improved soil and water conservation capacity and agricultural activities. Short-term abandonment led to SOC loss, while replanting fruit trees and crops increased SOC. Our findings provides valuable insights for agricultural management and ecological restoration in terraced areas of the Loess Plateau and contributes to the development of effective carbon sequestration policies for terraced arable lands.