The Effects of Organic and Inorganic Amendments on Soil Microbial Biomass Carbon Under Maize (Zea mays) Cultivation in Buea, Southwest Region of Cameroon

Abstract

The application of various fertilizers have been adopted by farmers all over the world to secure food supply that can cope with rapid population growth and urbanization, this has led to concerns on their effect on the natural environment. This study aimed to determine the effects of municipal solid waste compost (MSWC) and urea on soil microbial biomass carbon (MBC) under maize (zea mays) production over a four-month period (April-July 2022). The experiment was a Randomized Complete Block Design (RCBD) with three replicates, and three treatments; organic fertilizer (OF), no fertilizer (NF), synthetic fertilizer (SF) with an amendment rate of 100 kg per hectare. Soil samples were collected at a depth of 0-15cm. The effects of soil amendments on MBC were determined using the chloroform fumigation extraction method. ANOVA was used to determine the difference in MBC. Results showed that MBC varied significantly before and after amendments (p<0.05). All treatments show increased MBC after amendment. However, the largest relative increase occurred in OF plots, an indication that amendment stimulated microbial biomass where baseline MBC was low, showing a highest relative increase of 218.13% compared to 86.49% and 18.59% in NF and SF plots respectively. These findings underscore the potential of organic amendments to provide labile carbon and nutrients that stimulate microbial growth, promoting soil health and sustainability in agricultural practices. More research is needed to understand the dynamics of MBC at different depths with amendments and the effects of seasons on MBC in the volcanic soils of Buea.