The population bomb is an oft repeated environmentalist myth that has no basis in fact. The Netherlands has a population density of around 150 per km2 whilst Kenya has a population density of @20 per km2- which is the over crowded country?
The Green Revolution in Asia has allowed population density there to almost double in the last twenty years without a major famine event in that time frame.
Africa's problem, and we are talking about Africa, is that its soils are low in potassium, nitrogen and sulphur- but aid groups won't allow the use of targeted fertilizers for fear of disrupting traditional lifestyles. Cast iron hoes are heavy to use and slow work rates meaning that a greater proportion of the population is required in farming- where new light-weight steel hoes have been used (Idjwi in the Congo for example) they have led to reduced work in the fields, adoption of less wasteful techniques like deep seeding and weeding, rises in school attendance, improvements in household hygeine as women are no longer required in the fields and even enough spare time to re-establish traditional furniture making and textile industries- but aid groups still insist on handing out traditional cast iron hoes. Mechanization of many of these farms is out of the question but even simple irrigation technology would make many of these farms less prone to drought. the use of lucerne crops to help fix nitrogen in the soil are opposed because they are not native to Africa. In short, many of these aid groups are committed to an ideology that starving to death because of traditional methods is preferable to living with modern methods and technology.