Extended Data Fig. 4. Gaps between current and optimal 2015 in terms of NUE, fertilizer use and manure application.
a, Current NUE and target NUE in 2015. b, Current and optimal fertilizer N use in croplands in 2015. The optimal fertilizer use was calculated according to the balance between required N input (determined by target NUE and harvested N) and other N inputs (manure, deposition, irrigation, biological N fixation). c, Current and target manure N recycling to the croplands. FSU, former Soviet Union; MENA, Middle East and North Africa; OECD, Organization for Economic Co-operation and Development; SSA, sub-Saharan Africa.