Have the agricultural production systems in the North China Plain changed towards to climate smart agriculture since 2000?

Developing climate-smart agricultural systems has become an important strategy to meet the food production, environmental and economic goals simultaneously. However, the comprehensive analyses on the climate-smartness of current agricultural production systems have been lack. Here, we assessed the changes in agricultural production systems and their influences on food productivity, greenhouse gas (GHG) emissions, food carbon footprint (CF), nitrogen and water use efficiency, and economic profit of major crops in the North China Plain (NCP) at sub-provincial level over 2000–2016. We further identified the prior areas and agronomic management practices to be improved where nitrogen and water use efficiency was low, CF was high, or/and economic profit was low. The results showed that wheat, maize, vegetables, and oil crops were always dominant crops in the NCP and maize planting area increased most among all crops types over 2000–2016. The non-uniformity of agricultural landscape led to the decline of Shannon-Wiener Index and Simpson’s diversity Index. Agricultural GHG emissions and CF had spatially explicit patterns, along with crop yields and agricultural inputs. Among the agricultural inputs, fertilizer played a dominant role and contributed about 58.0%, 81.6%, and 77.3% respectively to the CF of wheat, maize, and oil crops, and plastic film contributed up to 55.1% to the CF of vegetables. The CF had a decreasing trend, while nitrogen use efficiency, irrigation water use efficiency and economic profit had an increasing trend, mainly due to increased yields, reduced agricultural inputs including fertilizers and irrigation, and improved agronomic managements. This study demonstrates a framework to evaluate and improve the climate-smartness of agricultural production system accounting for the multiple objectives simultaneously, and provides theoretical guidance and practical methods for government and farmers to improve agricultural production systems.