Abstract
Soil organic carbon (SOC) determination is very important in the assessment of agronomic potential of a soil. The objective of this study was to determine SOC contents and stock distribution with depth in relation to selected soil properties. Five types of soils, namely, Mollic Endoaquents, Oxyaquic Paleudalfs, Oxyaquic Udifluvents, and Mollic Udifluvents from a humid tropical plain and Typic Eutrudepts from an adjacent foot slope, were studied. The soils have all developed from fluvial sediments. Morphological and physicochemical characteristics of the soils were obtained using standard methods. Soil texture varied across the different sites and within soil profiles with textural classes of genetic horizons ranging from sandy loam to heavy clay. The soils are generally young soils under development as indicated by their high silt/clay ratios which ranged between 0.23 and 2.45. All the soils were generally acidic with pH-H2O values ranging from 4.5 to 6.2. Exchangeable H+ and Al3+ ranged from 0.5 to 2.3 and 0.2 to 3.3 cmolckg−1, respectively. SOC contents are generally higher in surface horizons and decrease with depth. In general, SOC correlated significantly with bulk density (BD) (r = −0.648, p < 0.01 ), water holding capacity (r = 0.589, p < 0.01 ), exchangeable Al3+ (r = 0.707, p < 0.01 ), and exchangeable H+ (r = 0.456, p < 0.05 ). The correlation between SOC and exchangeable Al3+ was strongest in the Mollic Endoaquents (r = 0.931, p < 0.01 ). SOC contents correlated significantly with Munsell soil color attributes, explaining between 40 and 57% of SOC variation. Total SOC stocks at a depth of 100 cm varied between 260.1 and 363.5 t·ha−1, and the variation in SOC stocks across a profile appears to be controlled by genetic horizon depth, while land use type influences SOC stock variations across genetic surface horizons.
Highlights
Soil organic carbon (SOC) is a major indicator of soil quality and productivity and a key driver of most soil processes and functions
SOC is fundamental to the role played by soil in providing ecosystem services such as regulating services, provisioning services, cultural services, and supporting services such as nutrient cycling [2]
A lava flow of this eruption blocked the plain in the north, favoring the creation of a lake. is was followed by the draining of this lake by the Nkam River, causing its disappearance [55]. e northern and eastern parts of the Mbo plain are dominated by the Bamilekeplateau comprised of granite and gneiss, with very steep escarpments. e southern part of the plain is dominated by basalt lava flow from Mount Manengouba which descends progressively towards the plain [56]
Summary
Soil organic carbon (SOC) is a major indicator of soil quality and productivity and a key driver of most soil processes and functions. It influences nutrient retention, microaggregate formation and soil structure, water retention/ storage and infiltration, microbial activity, and pH buffering [1]. SOC is fundamental to the role played by soil in providing ecosystem services such as regulating services (e.g., carbon sequestration, climate and greenhouse gas regulations), provisioning services (e.g., food, water, fuel, fiber), cultural services (e.g., ecotourism and recreation), and supporting services such as nutrient cycling [2]. Apart from the influence of human activities, many biophysical factors influence SOC storage and distribution patterns (Table 1)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
