Impact of Acacia nilotica on Soil Organic Carbon: Implications for Arid Agroforestry with a Case Study of Sardarshahar, Rajasthan, India

Abstract

Soil organic carbon (SOC) is an important indicator of soil quality and plays a significant role in carbon sequestration and climate-change mitigation, particularly in arid ecosystems. In arid ecosystems, maintenance and enhancement of soil organic carbon is particularly important because low rainfall, high temperature, high evapotranspiration and sparse vegetation constrain organic matter accumulation. Agroforestry systems can improve soil organic carbon through litter deposition, root biomass, nutrient cycling and modification of soil microclimatic conditions. The present study evaluates the influence of Acacia nilotica on soil organic carbon in the arid region of Sardarshahar, Rajasthan, India. Soil samples were collected from beneath the tree canopy and from comparatively open areas at two soil depths, 0–15 cm and 15–30 cm. The study compares spatial and depth-wise variation in SOC associated with A. nilotica and examines its implications for carbon management in arid agroforestry systems. The results are expected to demonstrate the role of A. nilotica in improving soil carbon status and maintaining soil fertility under water-limited conditions. SOC under Acacia nilotica was 47.4% higher than the open area at 0-15 cm depth and 43.3 % higher than the open area at 15-30 cm depth. The observed variation in SOC may be associated with litter accumulation, root- derived organic inputs, nutrient cycling and modification of the soil microenvironment beneath the tree canopy. The findings suggest that A. nilotica can contribute to maintaining soil organic carbon.