Identifying the driving forces of non-grain production expansion in rural China and its implications for policies on cultivated land protection

The rapid expansion of non-grain production (NGP) on cultivated land is of increasing concern regarding grain security in China. Characterizing the developmental mechanism of different NGP types and their responses to current policies is essential for providing critical references for the improvement of cultivated land protection policy. This study was conducted to explore the driving forces of NGP expansion in Tongxiang during three periods (2000-2008, 2008-2012, and 2012-2015). We first mapped the distributions of four types of NGP using multi-temporal high-resolution aerial photos. Then, we identified the driving forces of different NGP types at the parcel level using multinomial logistic regression modelling with geophysical, proximate, neighbourhood and policy variables. Our results showed that the total NGP area in Tongxiang increased from 31.16 ha to 2491.84 ha from 2000 to 2015. Farming conditions, such as soil type and distance to rivers, contributed more than settlements networks to the expansion of NGP in the Tongxiang region. A continuous and significant neighbourhood effect was found among pond fish farming, nursery plantations and duck rearing, demonstrating the strong stimulation of converted NGP parcels to surrounding farmers. Surprisingly, the implementation of policies such as basic farmland and standardized farmland failed to inhibit and actually encouraged NGP expansion. The planning of the main-functional region of grain production had a positive effect on inhibiting the expansion of some NGP types at certain stages. Our study provides valuable insights into the driving forces of NGP expansion at the parcel level and its response to current policies. This study supplements existing research to fully understand the phenomenon of NGP from the perspective of land use decision-making.