Carbon mineralization from plant residue-amended soils under varying moisture conditions

2014

English

The effects of soil moisture content and source of carbon on soil carbon mineralization have not been fully investigated. Present study reported significant variations in soil carbon mineralization from soils with different plant residues as the sources of carbon at varying soil moisture contents. Soil samples were mixed with each of milled groundnut, mucuna, maize and bush fallow residues. Calculated fixed volumes of water were added to bring each sample to an air-dried moisture state, 50 % field moisture capacity, and the field moisture capacity state. A control sample was similarly treated but without plant residue additions. All samples were arranged in completely randomized design and incubated at room temperature for 130 days. Carbon mineralization was defined by the rate of CO2-C emissions from the samples during the incubation. The effect of moisture on mineralization was more pronounced at 50 % field capacity. Considerable variations in CO2 release reflected the dominant role of residue composition (N and C/N ratios) on soil C mineralization. The order of CO 2-C evolution increased as: bush fallow < maize = mucuna < groundnut. This demonstrates that, knowledge on residue composition and soil moisture condition is vital to soil organic matter management

Mohammed, A. M.; Naab, J. B.; Nartey, E.; Adiku, S. G. K.