Assessing the impacts of rural residential land and cropland transition on agricultural production in Northeast China

Transitions between cropland and rural residential land (RRL) significantly impact both the amount of cropland and the yields obtained, whereas these impacts were overlooked in the previous studies. Taking accumulated Normalized Difference Vegetation Index during the growing season as a surrogate of productivity, this study assessed the impacts of RRL expansion and reclamation on agricultural production between 2009 and 2018 in Northeast China (NEC), a region contributing one-fifth of the nation's total grain yield. Especially, the productivity gap between the RRL-reclaimed and traditional cropland was explored and discussed. From 2009 to 2018, the NEC has experienced an intense expansion and reclamation in RRL, resulting in approximately 6.66 x 10(4) ha of cropland disappearing and 1.32 x 10(4) ha supplemented. Transitions in land use between RRL and cropland decreased the regional crop production by 0.08%, with the percentage slightly lower than that of cropland that was lost (0.09%). This was mainly attributed to the productivity gap between the reclaimed and occupied cropland from/to RRL, with the former higher than the latter. Even so, the cropland reclaimed from RRL was less productive than traditional cropland in three provinces in NEC, ranging from 1.6% to 3.9%. This productivity gap varied by crop type and province. After discussing the productivity limitations, suggestions for future land use policy in rural China have been put forward.