Substantial amounts of soil organic carbon and macronutrients are stored in deep soil layers under bamboo plantations

Bamboo is well known for its fast growth, high productivity, and multipurpose uses in different industries. Although bamboo stands are claimed to stock considerable amount of carbon in their biomass and the soil, our knowledge of soil organic carbon (SOC) and macronutrient storage below 100 cm soil depth is limited. Therefore, the objective of this study was to evaluate (1) variations in SOC and macronutrient concentration and stocks up to 500 cm soil depth under different aged bamboo plantations and open forests; (2) the vertical distribution of SOC and macronutrients; and (3) the stratification of SOC along soil depths and stand ages of bamboo. SOC and macronutrient contents decreased with soil depth consistently following distance-decay spatial interaction models. The highest SOC stock was recorded in 30 years old bamboo plantation (243.3 Mg ha⁻¹), while the lowest was in 5 years old bamboo plantations (186.47 Mg ha⁻¹) in the 0–500 cm soil depth. The SOC and macronutrient concentrations in the 0–100 cm were higher in all the bamboo stands than in the open forest. The total carbon stocks increased with increasing bamboo stand age. The stratification ratio of SOC and SOC: clay under different aged bamboo plantations indicated a moderate soil quality and good soil structure. It is concluded that bamboo plantations can serve as effective carbon sinks, contributing to substantial accumulation of SOC and macronutrients in subsurface soil layers. This makes bamboo plantations on degraded land a sustainable strategy for climate change mitigation, soil conservation, and land restoration.