Does yield gap still matter? Evidence from rice production in China

Narrowing the yield gap is a crucial way to increase grain production without increasing cultivated land to meet the growing demand for food and nutrients. Although estimation of yield gap in major grains (rice, wheat and maize) has been extensively studied at the field and experimental levels in recent decades, hardly any rigorous evidence-based studies have been performed at the farm level for the last decade in China. In this study, we employ production functions to estimate the yield gaps in rice farming and examine the different rice gaps in, e.g., regions and cultivation systems, using data collected from 1,029 farms in China in 2017. The results show that rice yield gap still existed in the surveyed region, although almost all farms had already achieved their potential yield (with a 2% yield gap). Age and distance between homesteads and plot have a negative effect on the yield gap, while household assets play an important role in narrowing the yield gap at the household level. Yield gap also varies considerably among regions, cultivated systems (i.e., early, one-season and late rice) and varieties. Policies aimed at ensuring grain self-sufficiency are suggested to focus more on technological changes to improve the potential yield rather relying on narrowing the yield gap at the household/farm level in rice production.