Abstract

Author:
Joel Obiaderi Omeke, Regina Nkeiruka Ezejiofor, Victor Odiamehi Onokebhagbe

Doi: 10.26480/taec.01.2023.01.05

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

This study investigated carbon stock under different agricultural practices in tropical soils of Southeastern Nigeria in two distinct seasons. Six agricultural practices {Natural undisturbed forest land (NUFL); Afforestation (AFP); Continuous cultivated land (CCL); Cattle transit (CT); Grassland (GRL) and Uncultivated land (UCL)} were identified. Carbon stock and flux were investigated at three distinct depths (0-30, 30-60 and 60-90 cm). Experimental design adopted was randomized complete block design. Results showed that under NUFL practices, highest concentrations of carbon were obtained from soil aggregates (macro-aggregates: 1.86 and 1.93 g kg-1; micro-aggregates: 4.48 and 4.64 g kg-1) in both raining and dry seasons. Carbon concentrations in the studied sites diminished with depth. Highest soil organic carbon stock (SOCs) contents of 85.77 and 99.86 kg C ha-1 were obtained from site under NUFL practices. Carbon stocks in the study soils declined with depths 99.86 to 27.31 kg C ha-1; 89.49 to 48.13 kg C ha-1 in raining and dry seasons. High values of CO2 (4.96 and 7.77%) were obtained from soil under intensive cultivation (CCL) in both seasons. Maximum Net carbon fluxes (-22.35 and -23.31) were recorded in soils under CCL practices in raining season and dry season. Net carbon flux was consistently negative and significantly lower in soils under NUFL (-84.68 and -97.88) in both seasons. Conclusively, NUFL and AFP practices enhanced vegetation cover which reduced carbon emissions, improved storage of carbon as well as other soil properties with lower risk of soil degradation when compared to soil under other farming practices.