Some more determined ideas for the three PhD studies Isaac (N-cycling) Birhanu (C-cycling) Eric (modelling)

Research proposal PhD students How to closely link to LegumeChoice project What to do for the project and what on top for their doctoral requirements Develop a research program that meets the quality demand by the university Plan thoroughly their time in field and in Hohenheim Their planned support to the project and the support provided to them during field work

How to approach? Baseline – Typology definition including selection of field sites – LegumeChoice tool for legume selection Knowledge constraint – Soil fertility status at the selected sites across Actions Sites and partner countries as well – How do selected legume types/species react in a given environment? – Do they fullfil the expected functions desired by farmers? Soil fertility enhancement as fundament for other functions?

How to approach? Assessment – Assessment of current soil fertility status (add-on to activities of Vanlauwe/Titonell) – Approve linkage between typology and soil fertility considering also nutrient status of legumes – Country-explicit assessment to cover particular conditions and constraints (country comparison at a later stage) – Similar methodological approach in each country

How to approach? Activity 1 – Season 2015 – Focus on relevant soil properties: C, N, P (and K) – Detection of any limitation of properties relevant for successful N-fixation – Link with farm trials (needs still thorough thinking what will be done, also with respect to model needs, see slides by Carsten) – Each student covers one country? – Knowledge gains important for Activity 2

How to approach? Activity 2 – Winter 2015/2016 (study program in Hohenheim) – Focus on microbial C and N fluxes and pools (model calibration) – Incubation studies with representative soils from LegumeChoice feld sites and legume types/species (selection on basis of Activity 1) – Understand the underlying processes in the soil as input for model adjustment and Activity 3 – Scenario development

How to approach? Activity 3 – Season 2016 (baseline Season 2015, incubation studies and LegumeChoice decisions) – Process-based field trials to validate results obtained during incubation studies and model parameterization (C and N fluxes rather than stocks, knowledge transfer to farmers) – Decision on plots for more detailed soil analysis – Intra- or inter-country comparision (are farmers‘ demands country-explicit?) – Cross-check similar treatments or research questions across countries

Requirements Access to field sites (transportation) Student support (MSc and BSc students), think about support for field season 2016 Soil analysis Sourcing any relevant secondary data