Low technical efficiency and excessive usage of chemical fertilizer in grain production is a problem commonly faced by China and many other developing countries, which leads to serious environment pollution and high environmental governance cost. China is the largest rice producing and consuming country, and several kinds of rice are grown in China and all of which are important edible grain. However, there has been no systematic research on kind difference and provincial difference of technical efficiency of chemical fertilizer use (TEFU) for rice production. Using the data of China’s 22 rice production provinces from the China Agricultural Product Cost-Benefit Compilation and the China Statistical Yearbook, this study measures the TEFU for early indica rice, intermediary indica rice, late indica rice, and japonica rice production by using a stochastic frontier production function (SFPF) model, and then analyzes TEFU’s influencing factors using a Tobit model and conducts the robustness check using a panel data fixed effect model. We found that, on average, TEFU for four kinds of rice production were improved significantly during 1997–2018, increasing by 67.70%, 39.93%, 14.76%, and 21.88%, respectively. TEFU for China’s rice production have significant differences among different kinds and production provinces, and still have large improvement potential. Government’s fiscal support to agriculture, agricultural labor productivity, agricultural mechanization, effective irrigation, and implementation of the “Soil Testing and Formulated Fertilization Program” (STFFP) have significant positive impact on TEFU; and natural disaster and fertilizer price have significant negative impact on TEFU.

The problem of food insecurity has become increasingly critical across the world since 2015, which threatens the lives and livelihoods of people around the world and has historically been a challenge confined primarily to developing countries, to which the countries of Central Asia, as typical transition countries, cannot be immune either. Under this context, many countries including Central Asian countries have recognized the importance of trade openness to ensure adequate levels of food security and are increasingly reliant on international trade for food security. Using the 2001–2018 panel data of Central Asian countries, based on food security’s four pillars (including availability, access, stability, and utilization), this study empirically estimates the impact of trade openness and other factors on food security and traces a U-shaped (or inverted U-shaped) relationship between trade openness and food security by adopting a panel data fixed effect model as the baseline model, and then conducts the robustness test by using the least-squares (LS) procedure for the pooled data and a dynamic panel data (DPD) analysis with the generalized method of moments (GMM) approach, simultaneously. The results show that: (1) a U-shaped relationship between trade openness and the four pillars of food security was found, which means that beyond a certain threshold of trade openness, food security status tends to improve in Central Asian countries; (2) gross domestic product (GDP) per capita, GDP growth, and agricultural productivity have contributed to the improvement of food security. Employment in agriculture, arable land, freshwater withdrawals in agriculture, population growth, natural disasters, and inflation rate have negative impacts on food security; and (3) this study confirms that trade policy reforms can finally be conducive to improving food security in Central Asian countries. However, considering the effects of other factors, potential negative effects of trade openness, and vulnerability of global food trade network, ensuring reasonable levels of food self-sufficiency is still very important for Central Asian countries to achieve food security. Our research findings can provide scientific support for sustainable food system strategies in Central Asian countries.

How do Chinese agricultural exports to ASEAN (Association of Southeast Asian Nations) evolve? And what factors affected the evolution pattern? This study measures the trade margins of Chinese agricultural exports to ASEAN by utilizing the 2000-2015 Harmonized System's six-digit agricultural trade data, and further analyzes their determinants by developing an augmented gravity model of international trade. The results indicate that, the main growth source of Chinese agricultural exports to ASEAN has shifted from the extensive margin before the formal establishment of CAFTA (China-ASEAN Free Trade Area) in 2010 to the intensive margin since the formal establishment of CAFTA, but changes in Chinese agricultural exports to ASEAN have always mainly depended on the intensive margin. Since the formal establishment of CAFTA, the evolution pattern of Chinese agricultural exports to ASEAN has shifted from "more varieties, low price, and small quantity" to "less varieties, high price, and large quantity". Relative economic scale, relative population scale, capacity of agricultural export, trade integration, global financial crisis, and common border significantly affect the trade margins of Chinese agricultural exports to ASEAN.