acreage reduction policy; set-aside policy
A government policy, especially in rice farming, to reduce the total area of land under cultivation in order to control supply and support prices.
The government implemented an acreage reduction policy to adjust rice production.
生産調整 is the broader concept of production adjustment, while 減反政策 specifically refers to the policy of reducing cultivated acreage.
Compound of 減 (reduce), 反 (unit of land area, about 10 ares), and 政策 (policy).