Food security of Africa’s growing population strongly depends on closing the yield gap for cash crops like maize. This can be achieved by increasing the input of N and P fertilizers and applying artificial irrigation, which, however, could substantially increase greenhouse gas (GHG) emissions. Therefore, alternative approaches to intensification must be sought. This project aims to evaluate whether selected plant growth promoting bacteria (PGPB) isolated from agricultural environments in SA and Cameroon can mitigate the negative effects of chemical fertilizers and strengthen drought resistance of maize in degraded sub-Saharan soils. The project aims to establish an empirical link between the use of PGBP, reduced GHG emissions and improved soil quality by measuring GHG emissions and soil chemistry in pot and field experiments in SA and Cameroon. Known and newly isolated PGPB have been characterized and grown to sufficient numbers by project partners in RSA, Cameroon and Italy. Currently, pot and field experiments are ongoing in SA and Cameroon in which GHG emissions are monitored to explore whether better plant health can improve N uptake and thereby reduce nitrous oxide (N2O) emissions locally while improving soil quality by allocating more organic carbon through increased root and litter input. The Norwegian partner has provided equipment for GHG measurements and trained local staff on-site in flux and soil sampling. Gas and soil samples from ongoing experiments are sent to Norway for analysis and flux calculation. The Norwegian partner has also visited the newly established, Norwegian funded GHG laboratory at the Wondo Genet College of Forestry and National Resources, University Hawassa, Ethiopia, to promote South-South collaboration in GHG flux studies. The overall aim of the project is to contribute to developing novel, nature-based solutions to a sustainable intensivation of sub-Saharan crop production. If successful, inoculation approaches can be adapted and extended to Norwegian crop production, where inoculation experiments with N2O reducing bacteria have been proven successful.
Agriculture is a major sources of greenhouse gases (GHG). In Sub-Saharan Africa (SSA), rapid population growth and land scarcity call for increased productivity to ensure food security. Intensification drives farmers’ reliance on inorganic fertilizer which results in increased emissions of GFGs such as nitrous oxide (N2O). Moreover, climate change is predicted to lead to extended periods of drought, further increasing the need for chemical fertilizers. Therefore, alternative approaches to intensification must be sought. One promising approach is the use of plant growth promoting bacteria (PGPB), particularly rhizospheric actinobacteria. Actinobacteria enhance soil quality by increasing the bioavailability of key nutrients, improve soil fertility and inhibit plant pathogens. Additionally, they produce compounds which may alleviate abiotic stress in plants. Maize is an important staple food in SSA where it accounts for 40% of cereal production. We will evaluate whether selected PGPB isolated from natural environments in SA and Cameroon can alleviate negative effects of droughts in chemically fertilized maize. Bacteria with demonstrated bioactivities associated with plant growth promotion e.g. N fixation, P solubilization, biosurfactant and siderophore production, will be formulated into bacterial inoculums and tested in maize exposed to drought stress. We will also investigate whether applying these inoculums reduces GHG emissions by enhancing fertiliser uptake by the crop. Plant-microbe interactions will be studied using molecular techniques such as whole genome sequencing and transcriptomics to confirm the bacteria’s role in the observed phenotype. Bacterial strains will be selected for the isolation and characterization of selected bioactives, and for patenting of novel compounds. The project presents a novel approach towards developing feasible strategies to help achieve climate neutrality in agri-food systems in Africa.
