This chapter discusses the main agronomic factors underlying the projections of crop production presented in Chapter 3. The focus is on crop production in developing countries, for which the projections were unfolded into land and yield projections under rainfed (five land classes) and irrigated conditions. Although the underlying analysis was carried out at the level of individual countries, the discussion here is limited to presenting the results at the level of major regions, which unavoidably masks wide intercountry differences. The parameters underlying the livestock production projections will be discussed in Chapter 5. Selected technology issues such as the scope for further yield increases, technologies in support of sustainable agriculture and the role of biotechnology are discussed in Chapter 11. Issues of environment and the possible impact of climate change on crop production are the subjects of Chapters 12 and 13.