Changes in land requirements for food in the Philippines: A historical analysis

Land for food production is limited. We investigate how land demand for food develops as populations grow, diets change and agricultural practices become more intensive. The Philippines provide an excellent case: during the 20th century population grew tenfold implying similar increases in basic dietary needs. To quantify occurring changes, we link average dietary patterns to their arable land requirements. For this, we utilize data on population, dietary patterns and crop yields from 1910 to 2003. While average per capita food supply improved during the century, the amount of land required to feed a person declined, albeit not continuous: it was at about 2500 m2 in 1910, at 2000 m2 in 1960, at 1000 m2 in 1985, and did not change greatly since then. Accounting for population growth, this translates to a fourfold increase in total land required for food from 1910 to 2003. When investigating what drove the observed developments at national level, we find that in the first half of 20th century population growth was linked to increased land requirements, before strong increases in yields were enabling constant land requirements for about two decades. Recently, the combined effect of dietary change and population growth led again to increased land requirements for food. Different yield developments in individual crops caused shifts in the relative land requirements of different food items. Our findings suggest that developments in land requirements for food and underlying factors are often non-linear. Caution is warranted when discussing futures of global food supply, based on assumptions of linear or continuous trends.