The concentration of population growth in the poorest countries will make it harder for their governments to eradicate poverty and inequality; combat hunger and malnutrition; expand education enrolment and health systems; improve the provision of basic services; and implement other elements of a sustainable development agenda to ensure that no one is left behind (UN/DESA, Population Division, 2015). It showed that while African farm-level costs were comparable to those in Brazil and Thailand, this "competitiveness” was based on: (1) soil mining (the depletion of soil nutrient reserves, leading to soil degradation); and (2) extremely low returns to labour, reflecting few alternative employment opportunities for workers — hardly a model for poverty reduction (World Bank, 2009). Increasing the percentage of irrigated land in sub-Saharan Africa to the Indian levels of 1960 would cost approximately $114 billion.