Analysis on the spatio-temporal evolution and influencing factors of China's grain production

Analysis on the spatiotemporal pattern and driving force of the spatial deviation index of grain and economy in counties in China

Studying the spatial relationship and driving forces between grain production and economic development in China can assist in the coordinated development of economic growth and grain production in both China and other developing countries. Based on panel data from 2000 to 2019 covering 2018 county-level units in China, this study comprehensively investigated the spatial distribution, spatial differences, dynamic evolution of distribution, and driving factors of China's county-level spatial deviation index of grain and economy (SDIGE) using methods such as the standard deviation ellipse method, the three-stage nested decomposition of Theil index, kernel density estimation, and geographically weighted regression (GWR) model. The results show that (1) from 2000 to 2019, China's SDIGE showed a development trend of "up-down-up," and the highest SDIGE was in the northeast region, the lowest in the east region, and the spatial pattern of "high in the northeast-low in the east coast" was increasingly prominent. (2) In terms of spatial difference, the overall difference of SDIGE in China from 2000 to 2019 showed a rising trend of development; The average contribution rate of the regional difference to the overall difference was the lowest, maintained at about 17.82%; The average contribution rate of intra city and inter-county differences to the overall difference is the highest, which is about 34.20%. (3) In terms of the driving force, the level of economic development hurts SDIGE, while population density, industrial structure, fiscal decentralisation, and terrain fluctuation have a positive and negative impact on SDIGE. To alleviate the imbalance between China's economic development and grain production, it is necessary to implement differentiated policy measures tailored to the specific characteristics of different regions to assist agricultural producers and enhance the stability of grain production.

Coupling relationship and development patterns of agricultural emission reduction, carbon sequestration, and food security

In-depth exploration of the coupling relationship between agricultural emission reduction and carbon sequestration (ERCS) and food security provides an important basis for promoting sustainable low-carbon development in agriculture. This research investigates the coupling mechanisms and the current state of coordinated development of agricultural ERCS and food security using provincial panel data from 2001 to 2022 in China. The agricultural ERCS level shows an upward trend, with higher levels in the north and lower in the south; externalities are positive in the north but negative in the south. Significant dynamic interactions and spatial correlations between the agricultural ERCS and food security exist, with a local spatial agglomeration pattern of "north-south opposition". Areas of high-high agglomeration are mainly concentrated in the north, while low-low agglomeration areas are primarily in the south. High-high agglomeration areas drive growth in transitional and low-growth areas through diffusion effects. The average coupling coordination degree of provinces increased from 0.432 to 0.473, indicating more coordinated development, and with a decreasing polarization trend. The spatial distributions of the coupling coordination degree and the relative development index are higher in the north and lower in the south, with many areas showing high adjustment, low adjustment, and high antagonism, particularly in the south where the number of high antagonistic areas has decreased. Implementing differentiated development strategies between the north and the south, using spatial agglomeration characteristics to optimize regional policies, focusing on the diffusion effects of high-coupling coordination areas to drive the development of low-growth and transitional areas, and enhancing the lagged terms can promote sustainable coordinated agricultural development.

Spatiotemporal Pattern Evolution of Food and Nutrient Production in China

Ensuring food and nutrient supply is a crucial aspect of achieving food safety. With rapid population growth, urbanization, and social and economic development, the challenges related to China's food and nutrient production have become increasingly prominent. This paper analyzed the characteristics of the spatiotemporal pattern evolution of food and nutrient production in China from 1995 to 2020, utilizing the conversion of various food nutrients and the establishment of a gravity center model. The results showed that: (1) Food production exhibited increasing trends in China, six regions, and 90% of the provinces. Notably, the structure of food production underwent significant changes in China, East China, Central-South China, Southwest China, Northwest China, and 60% of the provinces. (2) The output of all categories of food nutrients demonstrated increasing trends in China, six regions, and most provinces. At three different geographical scales, the changes of six food nutrients production structure showed significant differences. (3) Natural, political, social, economic, and technological factors played pivotal roles in influencing the gravity centers of food and nutrient production in China. The gravity centers of cereal production shifted northeast, while those of root and tuber, oil crops, and stimulants production moved westward. Additionally, the gravity centers of sugar crop, pulse, vegetable, fruit, and aquatic product production moved southwest and those of livestock and poultry production shifted northward. (4) Affected by the food production, the gravity centers of food energy, food protein, and food carbohydrate production shifted northward, while those of food fat, food vitamins, and food minerals production shifted northwest, southwest, and westward, respectively. The results of this study are of great significance for policy adjustments pertaining to the distribution pattern of food production, food security stability, and sustainable development in China.

Assessing Grain Productivity Coupled with Farmers’ Behaviors Based on the Agro-Ecological Zones (AEZ) Model

This study presents a method that dynamically embeds constraints of farmers’ management and input levels to improve a traditional agro-ecological zones (AEZ) model to solve the problem of overestimation of grain production capacity. The proposed method is applied to Yuanjiang county in central China to evaluate the grain productivity of farmland and analyze its spatial distribution characteristics. Our results indicated that (1) The feasibility of the AEZ method coupled with farmers’ behavior had been verified, and the revised model can better improve the accuracy of the evaluation results. (2) Low-value areas of grain production potential are mainly distributed in the central region, high-value areas are mainly distributed in the southwest and northeast regions, and the spatial differentiation characteristics of production potential and total production capacity are the same. (3) The total grain productivity is 935,800 tons, and the total yield gap is 470,100 tons, which is 1.01 times the actual yield, indicating a large potential to increase grain production under the current technicality. The main contribution of this study is to propose a method to dynamically embed farmers’ behavioral factors into the traditional AEZ model, and apply this method to the actual farmland productivity evaluation in small-scale areas, which improves the reliability of the actual regional productivity evaluation results.

Spatiotemporal Heterogeneity Monitoring of Cropland Evolution and Its Impact on Grain Production Changes in the Southern Sanjiang Plain of Northeast China

High-speed cropland changes are taking place in Northeast China, bringing about the sustainable changes in ecological landscape and food production; however, the lack of continuous research limits the revelation of new findings in this region. The integrated approach of land migration tracking, ecological landscape and mathematical statistics was established to conduct a comprehensive survey of land change–landscape–food security in a typical grain-planting region of Northeast China to reveal new changes from 1990 to 2020. Results display that the cropland area continued to increase from 25,885.16 km2 in 1990 to 31,144.46 km2 in 2020, leading to the loss of forest land, grassland, water body and unused land. For cropland structure, the proportion of paddy fields in cropland increased rapidly from 7.18 to 39.53% during 1990–2020; in contrast, upland crops decreased sharply. The richness of landscape presented gradually complex characteristics with SHDI from 0.258 to 0.671 and other ecological indicators underwent similar changes with strong regularity. Total grain production displayed a continuous increase, with values from 523.79 × 104 t to 1839.12 × 104 t, increasing by 2.51 times from 1990 to 2020. We also revealed the contribution rate of unchanged upland crops to grain increments was the largest (i.e., 46.29%), and the conversion of internal cropland structure (i.e., the paddy fields converted from upland crops) contributed 12.17% from 1990 to 2020, showing a positive signal for food security. These new findings provide studies on land use change, ecological landscape and food security in China and abroad.

Spatiotemporal characteristics and influencing factors of grain yield at the county level in Shandong Province, China

China's food security has always been a high priority issue on the political agenda with rapid urbanization affecting agricultural land, and it is challenged by several factors, such as human activities, social politics and policy. Shandong is an important grain-producing province and the second most populous province in China. In this paper, the spatiotemporal characteristics of grain yield and their potential influencing factors were explored at the county level in Shandong by using panel data over a 19-year period. The location Gini coefficient (L-Gini) and exploratory spatial data analysis (ESDA) were used to study the spatial agglomeration characteristics of grain yield, and spatial regression methods (SRMs) were used to analyse the influencing factors. The results indicated that grain yield increased from 38.3 million metric tons to 53.2 million metric tons in 2000-2018, with a growth rate of approximately 28.0%. The increase in grain yield in Shandong was due to the driving effect of radiation from high-yield counties to surrounding moderate-yield counties. This revealed an upward trend of spatial polarization in Shandong's grain yield. In 2000-2018, the L-Gini and global Moran's I increased from 0.330 to 0.479 and from 0.369 to 0.528, respectively. The number of counties in high-high (HH) and low-low (LL) agglomeration areas increased, and the spatial polarization effect was significant. SRMs analysis showed that irrigation investment and non-grain attention have significant positive and negative effects on grain production, respectively. The spatial relationship between grain yield and its influencing factors was explored to provide a reference for formulating scientific and rational agricultural policies.