Assertion: grassland's area | /r/HasProperty | cleared for cropping
Facets:
value: during the collective period
type: TEMPORAL
Source sentences:
text: Vast areas of drier land have also been cleared for cropping; much was marginal for crop production and suffers from periodic drought, which led to the "dust bowl" of the 1930s.
text: In all but the coldest and driest zones, large areas of the better land have been cleared for crops, leaving the poorer pasture to extensive stock rearing; in traditional areas of subsistence farming this is due to increasing human population among agricultural groups; elsewhere expansion of crops into marginal lands has been in the hope of profit, which has often not been realized.
text: Mongolia is almost entirely pastoral; small areas that were cleared for cropping during the collective period have mostly been abandoned for economic reasons.