Calculated virtual surfaces used for feed production according to two alternative methodologies (see Sect. 2.2). (a) Method 1: assuming that the principal use (outlet) of its production determines whether the whole surface is attributed to food (resp. feed) production. (b) Method 2: assuming that the percentage of crop production outlet (food versus feed) is equal to its surface allocation. Note that “Other feed crops” is a composite category (sugar crops, vegetables; see method section). Pulses and roots and tuber are not represented on this graph because of their relative minor importance. 100 Mha are added to the “Other feed crops” category between 1961 and 1984 for statistical reasons (see Data section).