Effects of mulch types on soil physicochemical properties, carbon sequestration, growth and yield of Bambara groundnut [Vigna subterranea (L.) Verdc.] in Agbani Area Enugu State

Field trials were conducted in 2017 and 2018 planting season at the Teaching and Research Farm of the Faculty of Agriculture and Natural Resources Management, Enugu State University of Science and Technology, Agbani. The experiment was laid out in randomized complete block design with three replications. The treatments were six different mulching materials (wood shavings, grass mulch, black polythene, clear polythene mulch, sawdust and no mulch material). The obtained results showed that Bambara groundnut grown on plots mulched with Panicum maximum produced significantly (p < 0.05) the highest pod weight per plant 87.50 g plant -1 -1 (2017) and 95.10 g plant (2018) respectively when compared with the other treatments. The result showed a significant difference (p < 0.05) on the number of leaves, leaf area index, and the number of pods per plant at four and eight weeks after planting in 2017 and 2018 planting season respectively. Soil sample tests revealed that plots mulched with sawdust had the highest soil bulk density with a value of 1.43 g cm-3 (2017) and 1.39 g cm-3 (2018) whereas the lowest was recorded in the unmulched plots (control) [1.02 g cm-3 (2017) and 1.00 g cm-3 (2018). Plots mulched with sawdust had more carbon content [0.137 mg c ha-1 (2017) and 0.141 mg c ha-1 (2018)] than the other treatments. Whereas the lowest carbon sequestration value was recorded in control and clear polythene plot treatment with a value of 0.049 mg c ha-1 (2017) and 0.051 mg c ha-1 (2018) respectively. The study showed that that Bambara groundnut grown on plots mulched with sawdust had the highest carbon content than the other mulch type.