Quantifying Soil Carbon Stocks and Sequestration Rate under Tree Canopy Litter in Sudan Savannah

Abstract

Soils of the Sudan Savannah face severe degradation that threatens their ability to serve as soil organic carbon sinks. The impact of tree litter on soil carbon stock and carbon sequestration is essential for enhancing soil fertility, mitigating climate change effects, and sustaining agricultural productivity. Thus, on-farm field experiment was conducted near Biliya Sanda Gate, Usmanu Danfodiyo University, Sokoto, to investigate the contribution of tree canopy litter to soil carbon stock and carbon sequestration rate per year. The experiment was laid out in a Randomized Complete Block Design (RCBD) involving three treatments (Vachellia nilotica, Azadirachta indica, and open cultivated area). Soil samples were collected, prepared and analyzed for selected soil properties (Bulk density, pH and organic carbon) and soil carbon stocks and sequestration were computed using standard procedures. Data obtained was subjected to Analysis of Variance (ANOVA) and Least Significant Difference (LSD) test was used to separate significant means. Results showed that the treatments under the tree canopy significantly improved soil properties (Bulk density, pH and organic carbon), soil carbon stock and carbon sequestration rate than the open cultivated area. The soil carbon sequestration rate of the area in increasing order of the treatments was A. indica (29.03 t C ha-1 yr-1), followed by V. nilotica (20.19 t C ha-1 yr-1), and lastly the open area with the least carbon sequestration rate (11.10 t C ha-1 yr-1). The use of tree canopy in enhancing soil properties and carbon sequestration should be encouraged in the study area.