Von Thunen's model attempts to explain where agricultural activities will be located in relation to the market (the city). Read about Von Thunen's model HERE.
Boserup's Theory of population is contrasted with Malthus' Theory. Malthus believes that population growth will be eventually too fast for food production to catch up. Boserup believes that when greater food production is needed, humans will find a way either through intensifying land use or developing new equiptment. Read more about her theory HERE.