description
- Globally, the use of nitrogen (N) fertilizer for agricultural purposes is tremendous, with an estimated total of 120 million t/year. Due to high nitrification activity in the soil, much of the N applied to farmland (about 70%) is not absorbed by the crops and gets washed out, resulting in water pollution and the emission of nitrous oxide (N2O), a powerful greenhouse gas (298 times CO2 global warming effect). Suppressing the nitrification rate of agricultural soil could be a sustainable solution. Plant roots can exudate natural compounds that prevent nitrification, a process known as biological nitrification inhibition (BNI). Wheat and maize are staple cereals that require excess fertilizers, and their efficiency has not increased to meet future food demand since 1980. The main aim of this study is to screen root exudates secondary metabolites of diverse wheat and maize genotypes for their BNI compounds and also evaluate the BNI potential under drought stress. Even though wheat and maize are major cereals covering the largest area among food crops, the study of its root exudates and the potential presence of BNI compounds and related BNI capacity have scarcely been studied. Consequently, the discovery possibility of new BNI compounds remains minimally explored in these crops, and root exudate plasticity in response to environmental changes is still extremely limited. The evaluation and selection of crop varieties lowers the nitrogen fertilizer dependency and is suitability for sustainable agriculture translates into specific key activities; 1) biochemical characterization of agronomic and environmental traits of the germplasm collection, 2) measurement of secondary metabolites in root exudates of germplasm lines in glasshouse under drought stress conditions to explore the full diversity of natural metabolic variation and BNI activity, and 3) potential isolation of new BNI compounds, and understand how plant traits and phylogeny are associated to this capacity.