Does Decentralized Food Crop Cultivation Threaten Water-Land-Food Nexus? A Spatial Econometric Analysis

The coordinated development of the Water-Land-Food (WLF) nexus is important for realizing sustainable food production and ensuring national food security. Based on the symbiosis system theory, this study used the Entropy weight TOPSIS method to calculate the WLF nexus of 30 provinces, municipalities and autonomous regions in China from 2003 to 2019. Taking the problem of decentralized food crop cultivation in China as the breakthrough point and using the Panel Tobit Model to empirically explore the threat of decentralized food crop cultivation to the WLF nexus. The results indicated that: (i) The average level of decentralized food crop cultivation index in China for the period 2003–2019 is 2.599 and the growth rate is −12.64%, while the WLF nexus index is 0.317, and the growth rate is 2.42%. Decentralized food crop cultivation showed a fluctuating downward trend in all regions of China, especially in the southwest and northwest regions. However, the WLF nexus index level belonging to the northeastern and Huang-Huai-Hai regions of China is higher, which presents a trend of first decreasing and then increasing. (ii) While the extent of decentralized food crop cultivation threatens the coordination of the WLF nexus in China, it has a time lag. (iii) The decentralized food crop cultivation in non-food producing areas (NFPA) rather than major food producing areas (MFPA) will threaten the WLF nexus. (iv) Compared with the higher WLF nexus index region, the negative effect of decentralized food crop cultivation is more obvious in the lower index region. (v) WFL nexus in the adjacent provinces of China showed regional clustering. Decentralized food crop cultivation will threaten the WLF nexus both in the inner province and adjacent regions. This study argues that the government can use financial subsidies to correct the problem of decentralized food crop cultivation, optimize the level of agricultural outsourcing services, and improve the market for water and land rights, thereby enhancing the WLF system coordination in China.