Policy-oriented versus market-induced: Factors influencing crop diversity across China.

Crop diversity is crucial for sustainable farmland ecosystems and global sustainability, and thus is a popular subject of research in ecological economics, agricultural science, and geography. Many studies have revealed the individual impacts of government policies or market changes on crop diversity. However, research on the combined effects of both government policy interventions and market-induced substitutions on changing crop diversity remains limited. This study clarifies the underlying mechanisms leading to changes in crop diversity in light of the joint effects of policies on grain subsidy implemented by the government to encourage monocropping as well as the market-induced forces that stimulate diversified planting. We used Hubei Province, one of the main grain-producing areas in Central China, as a case study. The foremost contribution of this study is its exploration of a global understanding of policy-oriented versus market-induced forces in driving changes in crop diversity at the regional level. Policy-oriented forces played a leading role in the past decline in diversity by restraining an increase in market-induced crop diversity. This leading role was reliant on encouraging certain crops through grain subsidies provided according to the farmers' targeted land use to maximize labor productivity. On the whole, strong implementation of policies on grain subsidy have challenged sustainable farmland ecosystems because of the resulting reduction in crop diversity. We argue that the relationship between top-down food security-oriented policies and bottom-up market-induced crop substitutions for a sustainable farmland ecosystem should be immediately and completely coordinated, while regionally differentiated cropping regulations should also be considered. • Market-induced crop substitution is able to enhance crop diversity. • The national grain subsidy policy encourages large-scale farming with mono-cropping. • The effect of market-induced crop substitution is strongly constrained by the national grain subsidy policy. • The relationship between food safety-oriented grain subsidy policies and market-induced crop substitution should be urgently coordinated. [ABSTRACT FROM AUTHOR]