Soil organic carbon stocks under different land uses in Chure region of Makawanpur district, Nepal

Abstract

Soil C sequestration through enhanced land use is a good strategy to mitigate the increasing concentration of atmospheric CO2. A study was conducted in Chhatiwan VDC of Makawanpur District to compare soil organic carbon (SOC) stocks of four main land use types such as forest, degraded forest, Khet and Bari land. Stratified random sampling method was used for collecting soil samples. Organic carbon content was determined by Walkley and Black method. Total SOC stock of different types of land followed the order: as Forest (110.0 t ha-1) > Bari (96.5 t ha-1) > Khet (86.8 t ha-1) > Degraded land (72.0 t ha-1). The SOC% declined with soil depths. The SOC% at 0–20 cm depth was highest (1.26 %) that recorded in the forest soils and lowest (0.37%) at 80- 100cm depth in degraded forest land. Thus, the SOC stock varied with land use systems and soil depths. The study suggests a need for appropriate land use strategy and sustainable soil management practices to improve SOC stock.
 SAARC J. Agri., 16(2): 13-23 (2018)

Vertical Distribution of Soil Organic Carbon and Nitrogen in a Tropical Community Forest of Nepal

“…e average soil organic matter and nitrogen concentration in 1 m soil profile depth of tropical community forest was found to be 0.99% ± 0.45% and 0.10% ± 0.05%, respectively (Table 1). ese values were close to the values reported by Paudel and Sah [34] (1.74% ± 0.31% SOC and 0.111% ± 0.01% soil nitrogen in the mixed S. robusta forest), Sharma and Chhetri [28] (0.09% soil nitrogen) and Ghimire et al [35] (0.95% SOC in the S. robusta-dominated forest). is may be due to a similar forest type containing S. robusta as dominant forest species, physiographical range, climatic condition, and soil sampling.…”

“…is may be due to similar forest types containing S. robusta as dominant species. pH was lower than the values reported by Sigdel [ [35] in two S. robusta-dominated tropical forests of Nepal. International Journal of Forestry Research e ANOVA test shows that there was significant difference of SOC (p � 0.001) and nitrogen (p � 0.001) between different soil layers at 5% level of significance.…”

“…Gautam and Mandal [44] also reported positive correlation between SOC and nitrogen in a tropical moist forest in eastern Nepal. Negative correlation between SOC and bulk density of soil was also reported by Ali et al [46] and Ghimire et al [35].…”

“…e stock of SOC and nitrogen in tropical community forest was found to be 122.36 t/ha and 12.74 t/ha, respectively, within 1 m soil profile depth ( Table 2). Ghimire et al [35] quantified 110 t/ha SOC in 1 m soil profile depth in a tropical forest dominated by Shorea robusta in Makwanpur district of Nepal. Our study district (Chitwan) is the neighboring district to Makwanpur district where Ghimire et al's [35] study was conducted and our finding on SOC stock within 1 m soil profile depth is close to theirs.…”

“…Ghimire et al [35] quantified 110 t/ha SOC in 1 m soil profile depth in a tropical forest dominated by Shorea robusta in Makwanpur district of Nepal. Our study district (Chitwan) is the neighboring district to Makwanpur district where Ghimire et al's [35] study was conducted and our finding on SOC stock within 1 m soil profile depth is close to theirs. Result of this research on SOC stock in 1 m soil profile depth is more than that reported by Gurung et al [42] (96.53 t/ha) in S. robusta-dominated forests.…”