Soil Organic Carbon Distribution in a Humid Tropical Plain of Cameroon: Interrelationships with Soil Properties

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.

Soil Organic Carbon in Forest and Other Land Use Types at Bengkulu City, Indonesia

“…Soil organic carbon had positive correlation with field capacity, but the correlation was weak, = 0.42, -value < 0.01 r p (Figure 5D). In this study, the available water capacity was also negatively correlated with bulk density (Kome et al, 2021). The increased SOC may increase soil aggregate stability, reduce compaction, and lower the soil bulk density (McCauley et al, 2017).…”

“…Soil organic carbon also decreased in deeper soil in the upper Yellow River of China , in (Guo et al, 2016) the Lancangjiang River Basin, China , and (Zhou et al, 2020) the tropical plain in Cameroon . However, (Kome et al, 2021) despite having a lower concentration of carbon, deep soil has greater total SOC storage due to its greater soil mass (Gross In the forest, the litter biomass was not contributed by the ground cover, because the forest had the lowest ground cover (Table 1), but by fallen tree leaves. The thick litter in the forest is decomposed into humus and enriches the soil with organic matter which is accumulated mostly in A horizon .…”

Vegetation diversity and its interspecies association with merbau (Intsia bijuga) at three habitats of tropical rain forest in West Papua, Indonesia

“…While the HBPMS and HBGMS areas are located in one area, but physically the condition of the site is also different. However, the colors in the various horizons were greatly influenced either by organic matter accumulation or mottling (Kome et al 2021).…”

“…Although there were differences in the percentage of soil texture components in the three locations that were also physically different, merbau and vegetation that grew alongside them were also found in all three locations (Table 1). According to Table 4, there is varies in soil texture percentage (Khalil et al 2015;Kome et al 2021). Sandy loam for TWAGM, loam for HBPMS, and clay for HBGMS.…”

Effects of Bio-Slurry and Chemical Fertilizer Application on Soil Properties and Food Safety of Tomato (Solanum lycopersicum Mill.)

“…Te quality of soil determines environmental health [13] and food safety and quality [14], which could be expressed in terms of physico-chemical indicators [15,16]. Soil organic matter is considered as one of the most important indicators of soil quality as it controls many soil properties, such as nutrient cycling, soil structure maintenance, and pH bufering [9,17]. However, soil contamination by heavy metals is one of the factors that cause soil health deterioration and plant health problems [18].…”